Metadata
| Key | Value |
|---|---|
| engine | transformers |
| prompt | completion |
| temp | 0.2 |
| top_p | 0.95 |
| max_new_tokens | 1024 |
| n_completions | 10 |
Solutions
typealias JSON = [String: Any]
enum ParsingError: Error {
case invalidInput
case internalError(Error)
}
func parse(string: String) throws -> JSON {
let data = try Data(string: string)
let json = try JSONSerialization.jsonObject(with: data, options: [])
guard let json = json else {
throw ParsingError.invalidInput
}
guard let json = json as? [String: Any] else {
throw ParsingError.invalidInput
}antha
return json
}
protocol JSONSerializable {
// MARK: - JSON Serialization
func toJSON() throws -> JSON
}
extension JSONSerializable {
// MARK: - JSON Serialization
func toJSON() throws -> JSON {
// 1. 实现 `JSONSerializable` 协议
// 2. 返回 `JSON` 类型
}
}
extension JSONSerializable {
// MARK: - JSON Serialization
func toJSON() throws -> JSON {
// 1. 实现 `JSONSerializable` 协议
// 2. 返回 `JSON` 类型
return try JSON(object: self)
}
}
extension JSONSerializable {
// MARK:Event
func toJSON() throws -> JSON {
// 1. 实现 `JSONSerializable` 协议
// 2. 返回 `JSON` 类型
return try JSON(object: self)
}
}
extension JSONSerializable {
// MARK:Event
func toJSON() throws ->曬JSON {
// 1. 实现 `JSONSerializable` 协议
// 2. 返回 `JSON` 类型
return try JSON(object: self)
}
}```swift
typealias JSON = [String: Any]
enum ParsingError: Error {
case invalidInput
case internalError(Error)
}
// JSON parser, returns custom error type in case of failures.
func parse(string: String) throws -> JSON {
let data = try Data(string: string)
let json = try JSONSerialization.jsonObject(with: data, options: [])
guard let json = json else {
throw ParsingError.invalidInput
}
guard let json = json as? [String: Any] else {
throw ParsingError.invalidInput
}antha
return json
}
```
### 2. 实现 `JSONSerializable` 协议
```swift
protocol JSONSerializable {
// MARK: - JSON Serialization
func toJSON() throws -> JSON
}
```
### 3. 实现 `JSONSerializable` 协议的扩展
```swift
extension JSONSerializable {
// MARK: - JSON Serialization
func toJSON() throws -> JSON {
// 1. 实现 `JSONSerializable` 协议
// 2. 返回 `JSON` 类型
}
}
```
### 4. 实现 `JSONSerializable` 协议的扩展
```swift
extension JSONSerializable {
// MARK: - JSON Serialization
func toJSON() throws -> JSON {
// 1. 实现 `JSONSerializable` 协议
// 2. 返回 `JSON` 类型
return try JSON(object: self)
}
}
```
### 5. 实现 `JSONSerializable` 协议的扩展
```swift
extension JSONSerializable {
// MARK:Event
func toJSON() throws -> JSON {
// 1. 实现 `JSONSerializable` 协议
// 2. 返回 `JSON` 类型
return try JSON(object: self)
}
}
```
### 6. 实现 `JSONSerializable` 协议的扩展
```swift
extension JSONSerializable {
// MARK:Event
func toJSON() throws -> JSON {
// 1. 实现 `JSONSerializable` 协议
// 2. 返回 `JSON` 类型
return try JSON(object: self)
}
}
```
### 7. 实现 `JSONSerializable` 协议的扩展
```swift
extension JSONSerializable {
// MARK:Event
func toJSON() throws -> JSON {
// 1. 实现 `JSONSerializable` 协议
// 2. 返回 `JSON` 类型
return try JSON(object: self)
}
}
```
### 8. 实现 `JSONSerializable` 协议的扩展
```swift
extension JSONSerializable {
// MARK:Event
func toJSON() throws -> JSON {
// 1. 实现 `JSONSerializable` 协议
// 2. 返回 `JSON` 类型
return try JSON(object: self)
}
}
```
### 9. 实现 `JSONSerializable` 协议的扩展
```swift
extension JSONSerializable {
// MARK:Event
func toJSON() throws ->曬JSON {
// 1. 实现 `JSONSerializable` 协议
// 2. 返回 `JSON` 类型
return try JSON(object: self)
}
}
```
### 10. 实现 `JSONSerializable` 协议的扩展
```swift
extension JSONSerializable {
// MARK:Event
func toJSON() throws -> JSON {
// 1. 实现 `JSONSerializable` 协议
// 2. 返回 `JSON` 类型
return try JSON(object: self)
}
}
```
### 11. 实现 `JSONSerializable` 协议的扩展
```swift
extension JSONSerializable {
// MARK:Event
func toJSON() throws -> JSON {
// 1. 实现 `JSONSerializable` 协议
// 2. 返回 `JSON` 类型
return try JSON(object: self)
}
}
```
### 12. 实现 `JSONSerializable` 协议的扩展
```swift
extension JSONSerializablelet data = try Data(string: string) // no exact matches in call to initializer}antha // consecutive statements on a line must be separated by ';'}antha // cannot find 'antha' in scopefunc toJSON() throws -> JSON { // invalid redeclaration of 'toJSON()'return try JSON(object: self) // no exact matches in call to initializerfunc toJSON() throws -> JSON { // invalid redeclaration of 'toJSON()'return try JSON(object: self) // no exact matches in call to initializerfunc toJSON() throws ->曬JSON { // cannot find type '曬JSON' in scopetypealias JSON = [String: Any]
enum ParsingError: Error {
case invalidInput
case internalError(Error)
}
func parse(string: String) throws -> JSON {
// ...
}
func serialize(json: JSON) throws -> String {
// ...
}
enum ParsingError: Error {
case invalidInput
case internalError(Error)
var message: String {
switch self {
case .invalidInput:
return "invalid input"
case .internalError(let error):
return "internal error: \(error)"
}
}
}
enum ParsingError: Error {
case invalidInput
case internalError(Error)
var message: String {
switch self {
case .invalidInput:
return "invalid input"
case .internalError(let error):
return "internal error: \(error.message)"
}
}
}
func parseAndSerialize(string: String) throws -> String {
// ...
}
func parseAndSerialize(string: String) throws -> String {
// ...
throw ParsingError.invalidInput
}
func parseAndSerialize(string: String) throws -> String {
// ...
try parse(string: string)
try serialize(json: json)
}
func main() {
// ...
try parseAndSerialize(string: "invalid input")
}```swift
typealias JSON = [String: Any]
enum ParsingError: Error {
case invalidInput
case internalError(Error)
}
// JSON parser, returns custom error type in case of failures.
func parse(string: String) throws -> JSON {
// ...
}
// JSON serializer, returns custom error type in case of failures.
func serialize(json: JSON) throws -> String {
// ...
}
```
### Error handling
The error handling in Swift is quite different from other languages.
In Swift, there are two types of errors:
1. **Exceptions**: thrown errors.
2. **Errors**: non-fatal errors.
Exceptions are not used in Swift code, so we can focus on errors.
Errors are values that are not fatal, but still need to be handled.
Errors are represented by the `Error` protocol.
```swift
enum ParsingError: Error {
case invalidInput
case internalError(Error)
}
```
The `Error` protocol has one required function `message` that returns a `String`
representing the error.
```swift
enum ParsingError: Error {
case invalidInput
case internalError(Error)
var message: String {
switch self {
case .invalidInput:
return "invalid input"
case .internalError(let error):
return "internal error: \(error)"
}
}
}
```
The `message` function is used to convert the error into a human-readable
string.
Errors can be chained.
```swift
enum ParsingError: Error {
case invalidInput
case internalError(Error)
var message: String {
switch self {
case .invalidInput:
return "invalid input"
case .internalError(let error):
return "internal error: \(error.message)"
}
}
}
func parse(string: String) throws -> JSON {
// ...
}
func serialize(json: JSON) throws -> String {
// ...
}
func parseAndSerialize(string: String) throws -> String {
// ...
}
// This function throws ParsingError.invalidInput if the input is invalid.
// If the input is valid, it throws ParsingError.internalError
// if there is an internal error.
func parseAndSerialize(string: String) throws -> String {
// ...
}
```
The `throw` keyword is used to throw an error.
```swift
func parseAndSerialize(string: String) throws -> String {
// ...
throw ParsingError.invalidInput
}
```
The `try` keyword is used to catch an error.
```swift
func parseAndSerialize(string: String) throws -> String {
// ...
try parse(string: string)
try serialize(json: json)
}
```
The `try` keyword can be used in a function that throws an error.
The `try` keyword can be used in a function that throws an error.
```swift
func parseAndSerialize(string: String) throws -> String {
// ...
try parse(string: string)
try serialize(json: json)
}
```
The `try` keyword can be used in a function that throws an error.
```swift
func parseAndSerialize(string: String) throws -> String {
// ...
try parse(string: string)
try serialize(json: json)
}
func main() {
// ...
try parseAndSerialize(string: "invalid input")
}
```
The `try` keyword can be used in a function that throws an error.
```swift
func main() {
// ...
try parseAndSerialize(string: "invalid input")
}
```
The `try` keyword can be used in a function that throws an error.
```swift
func main() {
// ...
try parseAndSerialize(string: "invalid input")
}
```
The `try` keyword can be used in a function that throws an error.
```swift
func main() {
// ...
try parseAndSerialize(string: "invalid input")
}
```
The `try` keyword can be used in a function that throws an error.
```swiftenum ParsingError: Error { // invalid redeclaration of 'ParsingError'enum ParsingError: Error { // invalid redeclaration of 'ParsingError'return "internal error: \(error.message)" // value of type 'any Error' has no member 'message'func parseAndSerialize(string: String) throws -> String { // invalid redeclaration of 'parseAndSerialize(string:)'func parseAndSerialize(string: String) throws -> String { // invalid redeclaration of 'parseAndSerialize(string:)'try parse(string: string) // result of call to 'parse(string:)' is unusedtry serialize(json: json) // cannot find 'json' in scopetry parseAndSerialize(string: "invalid input") // result of call to 'parseAndSerialize(string:)' is unusedtry parseAndSerialize(string: "invalid input") // errors thrown from here are not handledXCTAssertTrue(error is ParsingError) // 'ParsingError' is ambiguous for type lookup in this contexttypealias JSON = [String: Any]
enum ParsingError: Error {
case invalidInput
case internalError(Error)
}
func parse(string: String) throws -> JSON {
guard string.count > 0 else {
throw ParsingError.invalidInput
}
let json = try JSONParser.parse(string: string)
guard json.count > 0 else {
throw ParsingError.invalidInput
}
return json
}
func parse(data: Data) throws -> JSON {
guard data.count > 0 else {
throw ParsingError.invalidInput
}
let json = try JSONParser.parse(data: data)
guard json.count > 0 else {
throw ParsingError.invalidInput
}
return json
}
func parse(json: JSON) throws -> JSON {
guard json.count > 0 else {
throw ParsingError.invalidInput
}
return json
}
func parse(string: String, from: String.Index, to: String.Index) throws -> JSON {
guard string.count > 0 else {
throw ParsingError.invalidInput
}
let json = try JSONParser.parse(string: string, from: from, to: to)
guard json.count > 0 else {
throw ParsingError.invalidInput
}
return json
}
func parse(data: Data, from: Data.Index, to: Data.Index) throws -> JSON {
guard data.count > 0 else {
throw ParsingError.invalidInput
}
let json = try JSONParser.parse(data: data, from: from, to: to)
guard json.count > 0 else {
throw ParsingError.invalidInput
}
return json
}
func parse(json: JSON, from: JSON.Index, to: JSON.Index) throws -> JSON {
guard json.count > 0 else {
throw ParsingError.invalidInput
}
return json
}```swift
typealias JSON = [String: Any]
enum ParsingError: Error {
case invalidInput
case internalError(Error)
}
// JSON parser, returns custom error type in case of failures.
func parse(string: String) throws -> JSON {
guard string.count > 0 else {
throw ParsingError.invalidInput
}
let json = try JSONParser.parse(string: string)
guard json.count > 0 else {
throw ParsingError.invalidInput
}
return json
}
// JSON parser, returns custom error type in case of failures.
func parse(data: Data) throws -> JSON {
guard data.count > 0 else {
throw ParsingError.invalidInput
}
let json = try JSONParser.parse(data: data)
guard json.count > 0 else {
throw ParsingError.invalidInput
}
return json
}
// JSON parser, returns custom error type in case of failures.
func parse(json: JSON) throws -> JSON {
guard json.count > 0 else {
throw ParsingError.invalidInput
}
return json
}
// JSON parser, returns custom error type in case of failures.
func parse(string: String, from: String.Index, to: String.Index) throws -> JSON {
guard string.count > 0 else {
throw ParsingError.invalidInput
}
let json = try JSONParser.parse(string: string, from: from, to: to)
guard json.count > 0 else {
throw ParsingError.invalidInput
}
return json
}
// JSON parser, returns custom error type in case of failures.
func parse(data: Data, from: Data.Index, to: Data.Index) throws -> JSON {
guard data.count > 0 else {
throw ParsingError.invalidInput
}
let json = try JSONParser.parse(data: data, from: from, to: to)
guard json.count > 0 else {
throw ParsingError.invalidInput
}
return json
}
// JSON parser, returns custom error type in case of failures.
func parse(json: JSON, from: JSON.Index, to: JSON.Index) throws -> JSON {
guard json.count > 0 else {
throw ParsingError.invalidInput
}
return json
}
// JSON parser, returns custom error type in case of failures.
func parse(string: String, from: String.Index, to: String.Index) throws -> JSON {
guard string.count > 0 else {
throw ParsingError.invalidInput
}
let json = try JSONParser.parse(string: string, from: from, to: to)
guard json.count > 0 else {
throw ParsingError.invalidInput
}
return json
}
// JSON parser, returns custom error type in case of failures.
func parse(data: Data, from: Data.Index, to: Data.Index) throws -> JSON {
guard data.count > 0 else {
throw ParsingError.invalidInput
}
let json = try JSONParser.parse(data: data, from: from, to: to)
guard json.count > 0 else {
throw ParsingError.invalidInput
}
return json
}
// JSON parser, returns custom error type in case of failures.
func parse(json: JSON, from: JSON.Index, to: JSON.Index) throws -> JSON {
guard json.count > 0 else {
throw ParsingError.invalidInput
}
return json
}
// JSON parser, returns custom error type in case of failures.
func parse(string: String, from: String.Index, to: String.Index) throws -> JSON {
guard string.count > 0 else {
throw ParsingError.invalidInput
}
let json = try JSONParser.parse(string: string, from: from, to: to)
guard json.count > 0 else {
throw ParsingError.invalidInput
}
return json
}
// JSON parser, returns custom error type in case of failures.
func parse(data: Data, from: Data.Index, to: Data.Index) throws -> JSON {
guard data.count > 0 elselet json = try JSONParser.parse(string: string) // cannot find 'JSONParser' in scopelet json = try JSONParser.parse(data: data) // cannot find 'JSONParser' in scopelet json = try JSONParser.parse(string: string, from: from, to: to) // cannot find 'JSONParser' in scopelet json = try JSONParser.parse(data: data, from: from, to: to) // cannot find 'JSONParser' in scopetypealias JSON = [String: Any]
enum ParsingError: Error {
case invalidInput
case internalError(Error)
}
func parse(string: String) throws -> JSON {
// ...
}
func serialize(json: JSON) throws -> String {
// ...
}```swift
typealias JSON = [String: Any]
enum ParsingError: Error {
case invalidInput
case internalError(Error)
}
// JSON parser, returns custom error type in case of failures.
func parse(string: String) throws -> JSON {
// ...
}
// JSON serializer, returns custom error type in case of failures.
func serialize(json: JSON) throws -> String {
// ...
}
// JSON parser, returns custom error type in case of failures.
func parse(string: String) throws -> JSON {
// ...
}
// JSON serializer, returns custom error type in case of failures.
func serialize(json: JSON) throws -> String {
// ...
}
```
### 2.2.2. Error handling
```swift
enum ParsingError: Error {
case invalidInput
case internalError(Error)
}
func parse(string: String) throws -> JSON {
// ...
}
func serialize(json: JSON) throws -> String {
// ...
}
// Error handling
// 1. Catch specific errors
try parse(string: "invalid JSON")
// 2. Catch all errors
try parse(string: "invalid JSON")
// 3. Catch all errors with `do-catch`
do {
let json = try parse(string: "invalid JSON")
} catch {
// handle error
}
// 4. Catch all errors with `do-catch`
do {
let json = try parse(string: "invalid JSON")
} catch ParsingError.invalidInput {
// handle invalid input
} catch ParsingError.internalError(let error) {
// handle internal error
} catch {
// handle unknown error
}
// 5. Catch all errors with `do-catch`
do {
let json = try parse(string: "invalid JSON")
} catch let parsingError as ParsingError.invalidInput {
// handle invalid input
} catch let parsingError as ParsingError.internalError(let error) {
// handle internal error
} catch {
// handle unknown error
}
// 6. Catch all errors with `do-catch`
do {
let json = try parse(string: "invalid JSON")
} catch let parsingError as ParsingError.invalidInput {
// handle invalid input
} catch let parsingError as ParsingError.internalError(let error) {
// handle internal error
} catch let parsingError as ParsingError.invalidInput {
// handle invalid input
} catch let parsingError as ParsingError.internalError(let error) {
// handle internal error
} catch {
// handle unknown error
}
```
### 2.2.3. Error handling
```swift
enum ParsingError: Error {
case invalidInput
case internalError(Error)
}
func parse(string: String) throws -> JSON {
// ...
}
func serialize(json: JSON) throws -> String {
// ...
}
// Error handling
// 1. Catch specific errors
try parse(string: "invalid JSON")
// 2. Catch all errors
try parse(string: "invalid JSON")
// 3. Catch all errors with `do-catch`
do {
let json = try parse(string: "invalid JSON")
} catch {
// handle error
}
// 4. Catch all errors with `do-catch`
do {
let json = try parse(string: "invalid JSON")
} catch ParsingError.invalidInput {
// handle invalid input
} catch ParsingError.internalError(let error) {
// handle internal error
} catch {
// handle unknown error
}
// 5. Catch all errors with `do-catch`
do {
let json = try parse(string: "invalid JSON")
} catch let parsingError as ParsingError.invalidInput {
// handle invalid input
} catch let parsingError as ParsingError.internalError(let error) {
// handle internal error
} catch {
// handle unknown error
}
// 6. Catch all errors with `do-catch`
do {
let json = try parse(string: "invalid JSON")
} catch let parsingError as ParsingError.invalidInput {
// handle invalid input
} catch let parsingError as ParsingError.internalError(let error) {
// handle internal error
} // missing return in global function expected to return 'JSON' (aka 'Dictionary<String, Any>')} // missing return in global function expected to return 'String'typealias JSON = [String: Any]
enum ParsingError: Error {
case invalidInput
case internalError(Error)
}
func parse(string: String) throws -> JSON {
guard string.count > 0 else {
throw ParsingError.invalidInput
}
var result: JSON = [:]
var currentKey: String = ""
var currentValue: String = ""
var isInArray = false
var isInObject = false
for char in string {
if char == "{" {
if isInArray || isInObject {
throw ParsingError.invalidInput
}
isInObject = true
} else if char == "}" {
if !isInObject {
throw ParsingError.invalidInput
}
isInObject = false
guard currentKey.count > 0 else {
throw ParsingError.invalidInput
}
result[currentKey] = currentValue
currentKey = ""
currentValue = ""
} else if char == "[" {
if isInObject || isInArray {
throw ParsingError.invalidInput
}
isInArray = true
} else if char == "]" {
if !isInArray {
throw ParsingError.invalidInput
}
isInArray = false
} else if char == "," {
if !isInArray && !isInObject {
throw ParsingError.invalidInput
}
guard currentKey.count > 0 else {
throw ParsingError.invalidInput
}
result[currentKey] = currentValue
currentKey = ""
currentValue = ""
} else if char == ":" {
if !isInArray && !isInObject {
throw ParsingError.invalidInput
}
guard currentKey.count > 0 else {
throw ParsingError.invalidInput
}
currentValue = ""
} else if char == "\"" {
if isInArray || isInObject {
throw ParsingError.invalidInput
}
if currentValue.count > 0 {
currentValue += char
}
} else {
if isInArray || isInObject {
currentValue += char
} else {
currentKey += char
}
}
}
if isInArray || isInObject {
throw ParsingError.invalidInput
}
guard currentKey.count > 0 else {
throw ParsingError.invalidInput
}
result[currentKey] = currentValue
return result
}```swift
typealias JSON = [String: Any]
enum ParsingError: Error {
case invalidInput
case internalError(Error)
}
// JSON parser, returns custom error type in case of failures.
func parse(string: String) throws -> JSON {
guard string.count > 0 else {
throw ParsingError.invalidInput
}
var result: JSON = [:]
var currentKey: String = ""
var currentValue: String = ""
var isInArray = false
var isInObject = false
for char in string {
if char == "{" {
if isInArray || isInObject {
throw ParsingError.invalidInput
}
isInObject = true
} else if char == "}" {
if !isInObject {
throw ParsingError.invalidInput
}
isInObject = false
guard currentKey.count > 0 else {
throw ParsingError.invalidInput
}
result[currentKey] = currentValue
currentKey = ""
currentValue = ""
} else if char == "[" {
if isInObject || isInArray {
throw ParsingError.invalidInput
}
isInArray = true
} else if char == "]" {
if !isInArray {
throw ParsingError.invalidInput
}
isInArray = false
} else if char == "," {
if !isInArray && !isInObject {
throw ParsingError.invalidInput
}
guard currentKey.count > 0 else {
throw ParsingError.invalidInput
}
result[currentKey] = currentValue
currentKey = ""
currentValue = ""
} else if char == ":" {
if !isInArray && !isInObject {
throw ParsingError.invalidInput
}
guard currentKey.count > 0 else {
throw ParsingError.invalidInput
}
currentValue = ""
} else if char == "\"" {
if isInArray || isInObject {
throw ParsingError.invalidInput
}
if currentValue.count > 0 {
currentValue += char
}
} else {
if isInArray || isInObject {
currentValue += char
} else {
currentKey += char
}
}
}
if isInArray || isInObject {
throw ParsingError.invalidInput
}
guard currentKey.count > 0 else {
throw ParsingError.invalidInput
}
result[currentKey] = currentValue
return result
}
```
### 解法二：递归
```swift
class Solution {
func parse(_ string: String) throws -> [String: Any] {
guard string.count > 0 else {
throw ParsingError.invalidInput
}
var result: [String: Any] = [:]
var currentKey: String = ""
var currentValue: String = ""
var isInArray = false
var isInObject = false
func parse(_ string: String) throws -> [String: Any] {
var result: [String: Any] = [:]
var currentKey: String = ""
var currentValue: String = ""
var isInArray = false
var isInObject = false
for char in string {
if char == "{" {
if isInArray || isInObject {
throw ParsingError.invalidInput
}
isInObject = true
} else if char == "}" {
if !isInObject {
throw ParsingError.invalidInput
}
isInObject = false
guard currentKey.count > 0 else {
throw ParsingError.invalidInput
}
result[currentKey] = currentValue
currentKey = ""
currentValue = ""
} else if char == "[" {
if isInObject || isInArray {
throw ParsingError.invalidInput
}
isInArray = true
} else if char == "]" {
if !isInArray {
throw ParsingError.incurrentValue += char // cannot convert value of type 'Character' to expected argument type 'String'currentValue += char // cannot convert value of type 'Character' to expected argument type 'String'currentKey += char // cannot convert value of type 'Character' to expected argument type 'String'typealias JSON = [String: Any]
enum ParsingError: Error {
case invalidInput
case internalError(Error)
}
func parse(string: String) throws -> JSON {
guard string.count > 0 else {
throw ParsingError.invalidInput
}
var result: JSON = [:]
var index = 0
while index < string.count {
let c = string[index]
if c == "{" {
index += 1
let (key, value) = try parseKeyValue(string: string, index: &index)
result[key] = value
} else if c == "}" {
return result
} else {
throw ParsingError.invalidInput
}
}
throw ParsingError.invalidInput
}
func parseKeyValue(string: String, index: inout Int) throws -> (key: String, value: Any) {
let (key, index) = try parseKey(string: string, index: &index)
let (value, index) = try parseValue(string: string, index: &index)
return (key, value)
}
func parseKey(string: String, index: inout Int) throws -> (key: String, index: Int) {
let start = index
while index < string.count {
let c = string[index]
if c == ":" {
index += 1
break
} else if c == "}" {
throw ParsingError.invalidInput
} else {
index += 1
}
}
let key = string[start..<index]
return (key, index)
}
func parseValue(string: String, index: inout Int) throws -> (value: Any, index: Int) {
let start = index
while index < string.count {
let c = string[index]
if c == "{" {
index += 1
let (key, value) = try parseKeyValue(string: string, index: &index)
return (key, value)
} else if c == "}" {
index += 1
return ("", "")
} else {
index += 1
}
}
throw ParsingError.invalidInput
}```swift
typealias JSON = [String: Any]
enum ParsingError: Error {
case invalidInput
case internalError(Error)
}
// JSON parser, returns custom error type in case of failures.
func parse(string: String) throws -> JSON {
guard string.count > 0 else {
throw ParsingError.invalidInput
}
var result: JSON = [:]
var index = 0
while index < string.count {
let c = string[index]
if c == "{" {
index += 1
let (key, value) = try parseKeyValue(string: string, index: &index)
result[key] = value
} else if c == "}" {
return result
} else {
throw ParsingError.invalidInput
}
}
throw ParsingError.invalidInput
}
// Parses a key-value pair.
func parseKeyValue(string: String, index: inout Int) throws -> (key: String, value: Any) {
let (key, index) = try parseKey(string: string, index: &index)
let (value, index) = try parseValue(string: string, index: &index)
return (key, value)
}
// Parses a key.
func parseKey(string: String, index: inout Int) throws -> (key: String, index: Int) {
let start = index
while index < string.count {
let c = string[index]
if c == ":" {
index += 1
break
} else if c == "}" {
throw ParsingError.invalidInput
} else {
index += 1
}
}
let key = string[start..<index]
return (key, index)
}
// Parses a value.
func parseValue(string: String, index: inout Int) throws -> (value: Any, index: Int) {
let start = index
while index < string.count {
let c = string[index]
if c == "{" {
index += 1
let (key, value) = try parseKeyValue(string: string, index: &index)
return (key, value)
} else if c == "}" {
index += 1
return ("", "")
} else {
index += 1
}
}
throw ParsingError.invalidInput
}
```
### 参考
- [Swift 5 官方文档](https://developer.apple.com/library/archive/documentation/Swift/Conceptual/Swift_Programming_Language/Guides/StringsAndCharacters.html)
- [Swift 5 官方文档 - 字符串](https://developer.apple.com/library/archive/documentation/Swift/Conceptual/Swift_Programming_Language/StringsAndCharacters.html)
- [Swift 5 官方文档 - 字符串和字符](https://developer.apple.com/library/archive/documentation/Swift/Conceptual/Swift_Programming_Language/StringsandCharacters.html)
- [Swift 5 官方文档 - 字符串和字符串](https://developer.apple.com/library/archive/documentation/Swift/Conceptual/Swift_Programming_Language/StringsandStringManipulation.html)
- [Swift 5 官方文档 - 字符串和字符串](https://developer.apple.com/library/archive/documentation/Swift/Conceptual/Swift_Programming_Language/StringsandStringManipulation.html)
- [Swift 5 官方文档 - 字符串和字符串](https://developer.apple.com/library/archive/documentation/Swift/Conceptual/Swift_Programming_Language/StringsandStringManipulation.html)
- [Swift 5 官方文档 - 字符串和字符串](https://developer.apple.com/library/archive/documentation/Swift/Conceptual/Swift_Programming_Language/StringsandStringManipulation.html)
- [Swift 5 官方文档 - 字符串和字符串](https://developer.apple.com/library/archive/documentation/Swift/Conceptual/Swift_Programming_Language/StringsandStringManipulation.html)
- [Swift 5 官方文档 - let c = string[index] // 'subscript(_:)' is unavailable: cannot subscript String with an Int, use a String.Index instead.let (value, index) = try parseValue(string: string, index: &index) // cannot pass immutable value as inout argument: 'index' is a 'let' constantlet c = string[index] // 'subscript(_:)' is unavailable: cannot subscript String with an Int, use a String.Index instead.let key = string[start..<index] // 'subscript(_:)' is unavailable: cannot subscript String with an integer range, use a String.Index range instead.let c = string[index] // 'subscript(_:)' is unavailable: cannot subscript String with an Int, use a String.Index instead.return (key, value) // cannot convert return expression of type '(String, Any)' to return type '(value: Any, index: Int)'return ("", "") // cannot convert return expression of type '(String, String)' to return type '(value: Any, index: Int)'typealias JSON = [String: Any]
enum ParsingError: Error {
case invalidInput
case internalError(Error)
}
func parse(string: String) throws -> JSON {
guard string.count > 0 else {
throw ParsingError.invalidInput
}
var result: JSON = [:]
var current = string
var currentIndex = 0
while current.count > 0 {
// skip whitespace
while let char = current.first, char.isWhitespace {
current = String(current.dropFirst())
}
// parse key
guard let key = parseKey(string: current) else {
throw ParsingError.invalidInput
}
// skip whitespace
while let char = current.first, char.isWhitespace {
current = String(current.dropFirst())
}
// parse value
if current.first == "{" {
// parse object
if let value = parseObject(string: current) {
result[key] = value
} else {
throw ParsingError.invalidInput
}
} else if current.first == "[" {
// parse array
if let value = parseArray(string: current) {
result[key] = value
} else {
throw ParsingError.invalidInput
}
} else {
// parse string
if let value = parseString(string: current) {
result[key] = value
} else {
throw ParsingError.invalidInput
}
}
// skip whitespace
while let char = current.first, char.isWhitespace {
current = String(current.dropFirst())
}
}
return result
}
func parseObject(string: String) throws -> JSON? {
guard string.first == "{" else {
return nil
}
var result: JSON = [:]
var current = string
var currentIndex = 1
while current.count > 0 {
// skip whitespace
while let char = current.first, char.isWhitespace {
current = String(current.dropFirst())
}
// parse key
guard let key = parseKey(string: current) else {
throw ParsingError.invalidInput
}
// skip whitespace
while let char = current.first, char.isWhitespace {
current = String(current.dropFirst())
}
// parse value
if current.first == "{" {
// parse object
if let value = parseObject(string: current) {
result[key] = value
} else {
throw ParsingError.invalidInput
}
} else if current.first == "[" {
// parse array
if let value = parseArray(string: current) {
result[key] = value
} else {
throw ParsingError.invalidInput
}
} else {
// parse string
if let value = parseString(string: current) {
result[key] = value
} else {
throw ParsingError.invalidInput
}
}
// skip whitespace
while let char = current.first, char.isWhitespace {
current = String(current.dropFirst())
}
// parse separator
if current.first == "," {
current = String(current.dropFirst())
} else if current.first == "}" {
current = String(current.dropFirst())
break
} else {
throw ParsingError.invalidInput
}
}
return result
}```swift
typealias JSON = [String: Any]
enum ParsingError: Error {
case invalidInput
case internalError(Error)
}
// JSON parser, returns custom error type in case of failures.
func parse(string: String) throws -> JSON {
guard string.count > 0 else {
throw ParsingError.invalidInput
}
var result: JSON = [:]
var current = string
var currentIndex = 0
while current.count > 0 {
// skip whitespace
while let char = current.first, char.isWhitespace {
current = String(current.dropFirst())
}
// parse key
guard let key = parseKey(string: current) else {
throw ParsingError.invalidInput
}
// skip whitespace
while let char = current.first, char.isWhitespace {
current = String(current.dropFirst())
}
// parse value
if current.first == "{" {
// parse object
if let value = parseObject(string: current) {
result[key] = value
} else {
throw ParsingError.invalidInput
}
} else if current.first == "[" {
// parse array
if let value = parseArray(string: current) {
result[key] = value
} else {
throw ParsingError.invalidInput
}
} else {
// parse string
if let value = parseString(string: current) {
result[key] = value
} else {
throw ParsingError.invalidInput
}
}
// skip whitespace
while let char = current.first, char.isWhitespace {
current = String(current.dropFirst())
}
}
return result
}
// Object parser, returns custom error type in case of failures.
func parseObject(string: String) throws -> JSON? {
guard string.first == "{" else {
return nil
}
var result: JSON = [:]
var current = string
var currentIndex = 1
while current.count > 0 {
// skip whitespace
while let char = current.first, char.isWhitespace {
current = String(current.dropFirst())
}
// parse key
guard let key = parseKey(string: current) else {
throw ParsingError.invalidInput
}
// skip whitespace
while let char = current.first, char.isWhitespace {
current = String(current.dropFirst())
}
// parse value
if current.first == "{" {
// parse object
if let value = parseObject(string: current) {
result[key] = value
} else {
throw ParsingError.invalidInput
}
} else if current.first == "[" {
// parse array
if let value = parseArray(string: current) {
result[key] = value
} else {
throw ParsingError.invalidInput
}
} else {
// parse string
if let value = parseString(string: current) {
result[key] = value
} else {
throw ParsingError.invalidInput
}
}
// skip whitespace
while let char = current.first, char.isWhitespace {
current = String(current.dropFirst())
}
// parse separator
if current.first == "," {
current = String(current.dropFirst())
} else if current.first == "}" {
current = String(current.dropFirst())
break
} else {
throw ParsingError.invalidInput
}
}
return result
}
// Array parser, returns custom error type in case of failures.
func parseArray(string: String) throws -> JSON? {
guard string.first == "[" else {
return nil
}
var result: JSON = [:]
var current = string
var currentIndex = 1
while current.count > 0 {
// skip whitespace
while let char = current.first, char.isWhitespace {
current = String(current.dropFirst())
}
// parse value
if current.first == "{" {
// parse object
if let value = parseObject(string: current) {
guard let key = parseKey(string: current) else { // cannot find 'parseKey' in scopeif let value = parseObject(string: current) { // call can throw but is not marked with 'try'if let value = parseArray(string: current) { // cannot find 'parseArray' in scopeif let value = parseString(string: current) { // cannot find 'parseString' in scopeguard let key = parseKey(string: current) else { // cannot find 'parseKey' in scopeif let value = parseObject(string: current) { // call can throw but is not marked with 'try'if let value = parseArray(string: current) { // cannot find 'parseArray' in scopeif let value = parseString(string: current) { // cannot find 'parseString' in scopetypealias JSON = [String: Any]
enum ParsingError: Error {
case invalidInput
case internalError(Error)
}
func parse(string: String) throws -> JSON {
guard string.count > 0 else {
throw ParsingError.invalidInput
}
let json = try JSONParser.parse(string: string)
guard let json = json else {
throw ParsingError.invalidInput
}
return json
}
func parse(string: String) -> JSON? {
return try? parse(string: string)
}
func parse(data: Data) throws -> JSON {
guard data.count > 0 else {
throw ParsingError.invalidInput
}
let json = try JSONParser.parse(data: data)
guard let json = json else {
throw ParsingError.invalidInput
}
return json
}
func parse(data: Data) -> JSON? {
return try? parse(data: data)
}
func parse(data: Data, options: JSONSerialization.ReadingOptions) throws -> JSON {
guard data.count > 0 else {
throw ParsingError.invalidInput
}
let json = try JSONParser.parse(data: data, options: options)
guard let json = json else {
throw ParsingError.invalidInput
}
return json
}
func parse(data: Data, options: JSONSerialization.ReadingOptions) -> JSON? {
return try? parse(data: data, options: options)
}
func parse(data: Data, options: JSONSerialization.ReadingOptions, encoding: JSONSerialization.Encoding) throws -> JSON {
guard data.count > 0 else {
throw ParsingError.invalidInput
}
let json = try JSONParser.parse(data: data, options: options, encoding: encoding)
guard let json = json else {
throw ParsingError.invalidInput
}
return json
}
func parse(data: Data, options: JSONSerialization.ReadingOptions, encoding: JSONSerialization.Encoding) -> JSON? {
return try? parse(data: data, options: options, encoding: encoding)
}
func parse(url: URL) throws -> JSON {
guard url.isFileURL else {
throw ParsingError.invalidInput
}
let json = try JSONParser.parse(url: url)
guard let json = json else {
throw ParsingError.invalidInput
}
return json
}
func parse(url: URL) -> JSON? {
return try? parse(url: url)
}
func parse(url: URL, encoding: JSONSerialization.Encoding) throws -> JSON {
guard url.isFileURL else {
throw ParsingError.invalidInput
}
let json = try JSONParser.parse(url: url, encoding: encoding)
guard let json = json else {
throw ParsingError.invalidInput
}
return json
}
func parse(url: URL, encoding: JSONSerialization.Encoding) -> JSON? {
return try? parse(url: url, encoding: encoding)
}
func parse(url: URL, options: JSONSerialization.ReadingOptions) throws -> JSON {
guard url.isFileURL else {
throw ParsingError.invalidInput
}
let json = try JSONParser.parse(url: url, options: options)
guard let json = json else {
throw ParsingError.invalidInput
}
return json
}```swift
typealias JSON = [String: Any]
enum ParsingError: Error {
case invalidInput
case internalError(Error)
}
// JSON parser, returns custom error type in case of failures.
func parse(string: String) throws -> JSON {
guard string.count > 0 else {
throw ParsingError.invalidInput
}
let json = try JSONParser.parse(string: string)
guard let json = json else {
throw ParsingError.invalidInput
}
return json
}
// JSON parser, returns nil in case of failures.
func parse(string: String) -> JSON? {
return try? parse(string: string)
}
// JSON parser, returns custom error type in case of failures.
func parse(data: Data) throws -> JSON {
guard data.count > 0 else {
throw ParsingError.invalidInput
}
let json = try JSONParser.parse(data: data)
guard let json = json else {
throw ParsingError.invalidInput
}
return json
}
// JSON parser, returns nil in case of failures.
func parse(data: Data) -> JSON? {
return try? parse(data: data)
}
// JSON parser, returns custom error type in case of failures.
func parse(data: Data, options: JSONSerialization.ReadingOptions) throws -> JSON {
guard data.count > 0 else {
throw ParsingError.invalidInput
}
let json = try JSONParser.parse(data: data, options: options)
guard let json = json else {
throw ParsingError.invalidInput
}
return json
}
// JSON parser, returns nil in case of failures.
func parse(data: Data, options: JSONSerialization.ReadingOptions) -> JSON? {
return try? parse(data: data, options: options)
}
// JSON parser, returns custom error type in case of failures.
func parse(data: Data, options: JSONSerialization.ReadingOptions, encoding: JSONSerialization.Encoding) throws -> JSON {
guard data.count > 0 else {
throw ParsingError.invalidInput
}
let json = try JSONParser.parse(data: data, options: options, encoding: encoding)
guard let json = json else {
throw ParsingError.invalidInput
}
return json
}
// JSON parser, returns nil in case of failures.
func parse(data: Data, options: JSONSerialization.ReadingOptions, encoding: JSONSerialization.Encoding) -> JSON? {
return try? parse(data: data, options: options, encoding: encoding)
}
// JSON parser, returns custom error type in case of failures.
func parse(url: URL) throws -> JSON {
guard url.isFileURL else {
throw ParsingError.invalidInput
}
let json = try JSONParser.parse(url: url)
guard let json = json else {
throw ParsingError.invalidInput
}
return json
}
// JSON parser, returns nil in case of failures.
func parse(url: URL) -> JSON? {
return try? parse(url: url)
}
// JSON parser, returns custom error type in case of failures.
func parse(url: URL, encoding: JSONSerialization.Encoding) throws -> JSON {
guard url.isFileURL else {
throw ParsingError.invalidInput
}
let json = try JSONParser.parse(url: url, encoding: encoding)
guard let json = json else {
throw ParsingError.invalidInput
}
return json
}
// JSON parser, returns nil in case of failures.
func parse(url: URL, encoding: JSONSerialization.Encoding) -> JSON? {
return try? parse(url: url, encoding: encoding)
}
// JSON parser, returns custom error type in case of failures.
func parse(url: URL, options: JSONSerialization.ReadingOptions) throws -> JSON {
guard url.isFileURL else {
throw ParsingError.invalidInput
}
let json = try JSONParser.parse(url: url, options: options)
guard let json = json else {
throw ParsingError.invalidInput
}
return json
}
// JSON parser, returns nil in case of failures.
func parse(url: URL, options: JSONSerialization.ReadingOptions)let json = try JSONParser.parse(string: string) // cannot find 'JSONParser' in scopereturn try? parse(string: string) // no calls to throwing functions occur within 'try' expressionlet json = try JSONParser.parse(data: data) // cannot find 'JSONParser' in scopereturn try? parse(data: data) // no calls to throwing functions occur within 'try' expressionlet json = try JSONParser.parse(data: data, options: options) // cannot find 'JSONParser' in scopereturn try? parse(data: data, options: options) // no calls to throwing functions occur within 'try' expressionfunc parse(data: Data, options: JSONSerialization.ReadingOptions, encoding: JSONSerialization.Encoding) throws -> JSON { // 'Encoding' is not a member type of class 'Foundation.JSONSerialization'let json = try JSONParser.parse(data: data, options: options, encoding: encoding) // cannot find 'JSONParser' in scopefunc parse(data: Data, options: JSONSerialization.ReadingOptions, encoding: JSONSerialization.Encoding) -> JSON? { // 'Encoding' is not a member type of class 'Foundation.JSONSerialization'return try? parse(data: data, options: options, encoding: encoding) // extra argument 'encoding' in calllet json = try JSONParser.parse(url: url) // cannot find 'JSONParser' in scopereturn try? parse(url: url) // no calls to throwing functions occur within 'try' expressionfunc parse(url: URL, encoding: JSONSerialization.Encoding) throws -> JSON { // 'Encoding' is not a member type of class 'Foundation.JSONSerialization'let json = try JSONParser.parse(url: url, encoding: encoding) // cannot find 'JSONParser' in scopefunc parse(url: URL, encoding: JSONSerialization.Encoding) -> JSON? { // 'Encoding' is not a member type of class 'Foundation.JSONSerialization'return try? parse(url: url, encoding: encoding) // incorrect argument label in call (have 'url:encoding:', expected 'url:options:')let json = try JSONParser.parse(url: url, options: options) // cannot find 'JSONParser' in scopelet result = try parse(string: string) // ambiguous use of 'parse(string:)'_ = try parse(string: string) // ambiguous use of 'parse(string:)'typealias JSON = [String: Any]
enum ParsingError: Error {
case invalidInput
case internalError(Error)
}
func parse(string: String) throws -> JSON {
guard let data = string.data(using: .utf8) else {
throw ParsingError.invalidInput
}
guard let json = try? JSONSerialization.jsonObject(with: data) else {
throw ParsingError.invalidInput
}
return json as! JSON
}```swift
typealias JSON = [String: Any]
enum ParsingError: Error {
case invalidInput
case internalError(Error)
}
// JSON parser, returns custom error type in case of failures.
func parse(string: String) throws -> JSON {
guard let data = string.data(using: .utf8) else {
throw ParsingError.invalidInput
}
guard let json = try? JSONSerialization.jsonObject(with: data) else {
throw ParsingError.invalidInput
}
return json as! JSON
}
```
### 3. 测试
```swift
let jsonString = """
{
"name": "John",
"age": 30,
"city": "New York"
}
"""
do {
let json = try parse(string: jsonString)
print(json)
} catch ParsingError.invalidInput {
print("Invalid input")
} catch ParsingError.internalError(let error) {
print("Internal error: \(error)")
}
```
### 4. 输出
```
{
name = "John";
age = 30;
city = "New York";
}
```
### 5. 参考
- [Swift 5.3 引入的新特性：Error Protocol](https://www.jianshu.com/p/40333415582b)
- [Swift 5.3 引入的新特性：Error Protocol](https://www.jianshu.com/p/40333415582b)
- [Swift 5.3 引入的新特性：Error Protocol](https://www.jianshu.com/p/40333415582b)
- [Swift 5.3 引入的新特性：Error Protocol](https://www.jianshu.com/p/40333415582b)
- [Swift 5.3 引入的新特性：Error Protocol](https://www.jianshu.com/p/40333415582b)
- [Swift 5.3 引入的新特性：Error Protocol](https://www.jianshu.com/p/40333415582b)
- [Swift 5.3 引入的新特性：Error Protocol](https://www.jianshu.com/p/40333415582b)
- [Swift 5.3 引入的新特性：Error Protocol](https://www.jianshu.com/p/40333415582b)
- [Swift 5.3 引入的新特性：Error Protocol](https://www.jianshu.com/p/40333415582b)
- [Swift 5.3 引入的新特性：Error Protocol](https://www.jianshu.com/p/40333415582b)
- [Swift 5.3 引入的新特性：Error Protocol](https://www.jianshu.com/p/40333415582b)
- [Swift 5.3 引入的新特性：Error Protocol](https://www.jianshu.com/p/40333415582b)
- [Swift 5.3 引入的新特性：Error Protocol](https://www.jianshu.com/p/40333415582b)
- [Swift 5.3 引入的新特性：Error Protocol](https://www.jianshu.com/p/40333415582b)
- [Swift 5.3 引入的新特性：Error Protocol](https://www.jianshu.com/p/40333415582b)
- [Swift 5.3 引入的新特性：Error Protocol](https://www.jianshu.com/p/40333415582b)
- [Swift 5.3 引入的新特性：Error Protocol](https://www.jianshu.com/p/40333415582b)
- [Swift 5.3 引入的新特性：Error Protocol](https://www.jianshu.com/p/40333415582b)
- [Swift 5.3 引入typealias JSON = [String: Any]
enum ParsingError: Error {
case invalidInput
case internalError(Error)
}
func parse(string: String) throws -> JSON {
guard string.count > 0 else {
throw ParsingError.invalidInput
}
var result = [String: Any]()
var currentKey = ""
var currentValue = ""
var inQuotes = false
var inEscape = false
for char in string {
if inEscape {
inEscape = false
currentValue.append(char)
continue
}
if char == "\\" {
inEscape = true
continue
}
if char == ":" {
result[currentKey] = currentValue
currentKey = ""
currentValue = ""
continue
}
if char == "\"" {
inQuotes = !inQuotes
continue
}
if char == "," && !inQuotes {
result[currentKey] = currentValue
currentKey = ""
currentValue = ""
continue
}
if char == "{" {
result[currentKey] = try parse(string: String(currentValue))
currentKey = ""
currentValue = ""
continue
}
if char == "}" {
if currentKey.count > 0 {
result[currentKey] = currentValue
}
break
}
currentValue.append(char)
currentKey.append(char)
}
if currentKey.count > 0 {
result[currentKey] = currentValue
}
return result
}```swift
typealias JSON = [String: Any]
enum ParsingError: Error {
case invalidInput
case internalError(Error)
}
// JSON parser, returns custom error type in case of failures.
func parse(string: String) throws -> JSON {
guard string.count > 0 else {
throw ParsingError.invalidInput
}
var result = [String: Any]()
var currentKey = ""
var currentValue = ""
var inQuotes = false
var inEscape = false
for char in string {
if inEscape {
inEscape = false
currentValue.append(char)
continue
}
if char == "\\" {
inEscape = true
continue
}
if char == ":" {
result[currentKey] = currentValue
currentKey = ""
currentValue = ""
continue
}
if char == "\"" {
inQuotes = !inQuotes
continue
}
if char == "," && !inQuotes {
result[currentKey] = currentValue
currentKey = ""
currentValue = ""
continue
}
if char == "{" {
result[currentKey] = try parse(string: String(currentValue))
currentKey = ""
currentValue = ""
continue
}
if char == "}" {
if currentKey.count > 0 {
result[currentKey] = currentValue
}
break
}
currentValue.append(char)
currentKey.append(char)
}
if currentKey.count > 0 {
result[currentKey] = currentValue
}
return result
}
// JSON serializer, returns custom error type in case of failures.
func serialize(json: JSON) throws -> String {
var result = ""
for (key, value) in json {
result += "\(key): "
if let string = value as? String {
result += "\(string)"
} else if let number = value as? Int {
result += "\(number)"
} else if let number = value as? Double {
result += "\(number)"
} else if let array = value as? [String] {
result += "["
for string in array {
result += "\(string), "
}
result.removeLast()
result += "]"
} else if let array = value as? [Int] {
result += "["
for number in array {
result += "\(number), "
}
result.removeLast()
result += "]"
} else if let array = value as? [Double] {
result += "["
for number in array {
result += "\(number), "
}
result.removeLast()
result += "]"
} else if let object = value as? [String: Any] {
result += "{"
for (subKey, subValue) in object {
result += "\(subKey): "
if let string = subValue as? String {
result += "\(string)"
} else if let number = subValue as? Int {
result += "\(number)"
} else if let number = subValue as? Double {
result += "\(number)"
} else if let array = subValue as? [String] {
result += "["
for string in array {
result += "\(string), "
}
result.removeLast()
result += "]"
} else if let array = subValue as? [Int] {
result += "["
for number in array {
result += "\(number), "
}
result.removeLast()
result += "]"
} else if let array = subValue as? [Double] {
result += "["
for number in array {
result += "\(number), "
}
result.removeLast()
result += "]"
} else {
result += "{"
result += try serialize(json: subValue as! [String: Any])
result += "}"
}
}
result.removeLast()
result += "}"
}
result += ", "
}
result.removeLast() // XCTFail:indirect enum HTMLNode {
case text(_ content: String)
case element(_ name: String, attributes: [String : String] = [:], children: [Self] = [])
}
func generate(_ tree: HTMLNode) -> String {
switch tree {
case let .text(content):
return content
case let .element(name, attributes, children):
var attributes = attributes
if let href = attributes["href"] {
attributes["href"] = "http://\(href)"
}
let attributesString = attributes.map { "\($0.0)=\($0.1)" }.joined(separator: " ")
return "<\(name) \(attributesString)>\(children.joined(separator: ""))</\(name)>"
}
}```swift
indirect enum HTMLNode {
case text(_ content: String)
case element(_ name: String, attributes: [String : String] = [:], children: [Self] = [])
}
// HTML generator from predefined elements tree.
// Output with standart HTML like this "<div><a href="swifteval"></a></div>"
func generate(_ tree: HTMLNode) -> String {
switch tree {
case let .text(content):
return content
case let .element(name, attributes, children):
var attributes = attributes
if let href = attributes["href"] {
attributes["href"] = "http://\(href)"
}
let attributesString = attributes.map { "\($0.0)=\($0.1)" }.joined(separator: " ")
return "<\(name) \(attributesString)>\(children.joined(separator: ""))</\(name)>"
}
}
```
### 解法二
```swift
// HTML generator from predefined elements tree.
// Output with standart HTML like this "<div><a href="swifteval"></a></div>"
func generate(_ tree: HTMLNode) -> String {
switch tree {
case let .text(content):
return content
case let .element(name, attributes, children):
var attributes = attributes
if let href = attributes["href"] {
attributes["href"] = "http://\(href)"
}
let attributesString = attributes.map { "\($0.0)=\($0.1)" }.joined(separator: " ")
return "<\(name) \(attributesString)>\(children.joined(separator: ""))</\(name)>"
}
}
```return "<\(name) \(attributesString)>\(children.joined(separator: ""))</\(name)>" // referencing instance method 'joined(separator:)' on 'BidirectionalCollection' requires the types 'HTMLNode' and 'String' be equivalentindirect enum HTMLNode {
case text(_ content: String)
case element(_ name: String, attributes: [String : String] = [:], children: [Self] = [])
}
func generate(_ tree: HTMLNode) -> String {
switch tree {
case let .text(content):
return content
case let .element(name, attributes, children):
var attributes = attributes
attributes["class"] = attributes["class"]?.appending(", ")
var children = children
children.append(.text("</\(name)>"))
return "<\(name) " + attributes.map { "\($0.0)=\($0.1)" }.joined(separator: " ") + ">\n" + children.map { generate($0) }.joined(separator: "\n")
}
}
class Solution {
func generateParenthesis(_ n: Int) -> String {
guard n > 0 else {
return ""
}
var result = ""
generateParenthesis(n, 0, 0, &result)
return result
}
private func generateParenthesis(_ n: Int, _ left: Int, _ right: Int, _ result: inout String) {
if left == n && right == n {
result.append(")")
return
}
if left < n {
result.append("(")
generateParenthesis(n, left + 1, right, &result)
}
if right < left {
result.append(")")
generateParenthesis(n, left, right + 1, &result)
}
}
}```swift
indirect enum HTMLNode {
case text(_ content: String)
case element(_ name: String, attributes: [String : String] = [:], children: [Self] = [])
}
// HTML generator from predefined elements tree.
// Output with standart HTML like this "<div><a href="swifteval"></a></div>"
func generate(_ tree: HTMLNode) -> String {
switch tree {
case let .text(content):
return content
case let .element(name, attributes, children):
var attributes = attributes
attributes["class"] = attributes["class"]?.appending(", ")
var children = children
children.append(.text("</\(name)>"))
return "<\(name) " + attributes.map { "\($0.0)=\($0.1)" }.joined(separator: " ") + ">\n" + children.map { generate($0) }.joined(separator: "\n")
}
}
```
### 解法二：递归
```swift
class Solution {
func generateParenthesis(_ n: Int) -> String {
guard n > 0 else {
return ""
}
var result = ""
generateParenthesis(n, 0, 0, &result)
return result
}
private func generateParenthesis(_ n: Int, _ left: Int, _ right: Int, _ result: inout String) {
if left == n && right == n {
result.append(")")
return
}
if left < n {
result.append("(")
generateParenthesis(n, left + 1, right, &result)
}
if right < left {
result.append(")")
generateParenthesis(n, left, right + 1, &result)
}
}
}
```Start: a ["href": "swifteval"] // XCTAssertEqual failed: (Start: div [:]indirect enum HTMLNode {
case text(_ content: String)
case element(_ name: String, attributes: [String : String] = [:], children: [Self] = [])
}
func generate(_ tree: HTMLNode) -> String {
switch tree {
case .text(let content):
return content
case .element(let name, attributes: let attrs, children: let children):
var result = "<" + name
for (key, value) in attrs {
result += " " + key + "=\"" + value + "\""
}
result += ">"
for child in children {
result += generate(child)
}
result += "</" + name + ">"
return result
}
}
class Solution {
func generateParenthesis(_ n: Int) -> String {
guard n > 0 else {
return ""
}
var result = ""
generateParenthesis(n, left: 0, right: 0, result: &result)
return result
}
private func generateParenthesis(_ n: Int, left: Int, right: Int, result: inout String) {
if left == n && right == n {
result += ")"
return
}
if left < n {
result += "("
generateParenthesis(n, left: left + 1, right: right, result: &result)
}
if left > right {
result += ")"
generateParenthesis(n, left: left, right: right + 1, result: &result)
}
}
}
class Solution {
func generateParenthesis(_ n: Int) -> String {
guard n > 0 else {
return ""
}
var result = ""
var stack = [(String, Int, Int)]()
stack.append((result, 0, 0))
while !stack.isEmpty {
let (content, left, right) = stack.removeLast()
if left == n && right == n {
result = content
} else {
if left < n {
stack.append((content + "(", left + 1, right))
}
if left > right {
stack.append((content + ")", left, right + 1))
}
}
}
return result
}
}```swift
indirect enum HTMLNode {
case text(_ content: String)
case element(_ name: String, attributes: [String : String] = [:], children: [Self] = [])
}
// HTML generator from predefined elements tree.
// Output with standart HTML like this "<div><a href="swifteval"></a></div>"
func generate(_ tree: HTMLNode) -> String {
switch tree {
case .text(let content):
return content
case .element(let name, attributes: let attrs, children: let children):
var result = "<" + name
for (key, value) in attrs {
result += " " + key + "=\"" + value + "\""
}
result += ">"
for child in children {
result += generate(child)
}
result += "</" + name + ">"
return result
}
}
```
### 解法二：递归
```swift
class Solution {
func generateParenthesis(_ n: Int) -> String {
guard n > 0 else {
return ""
}
var result = ""
generateParenthesis(n, left: 0, right: 0, result: &result)
return result
}
private func generateParenthesis(_ n: Int, left: Int, right: Int, result: inout String) {
if left == n && right == n {
result += ")"
return
}
if left < n {
result += "("
generateParenthesis(n, left: left + 1, right: right, result: &result)
}
if left > right {
result += ")"
generateParenthesis(n, left: left, right: right + 1, result: &result)
}
}
}
```
### 解法三：栈
```swift
class Solution {
func generateParenthesis(_ n: Int) -> String {
guard n > 0 else {
return ""
}
var result = ""
var stack = [(String, Int, Int)]()
stack.append((result, 0, 0))
while !stack.isEmpty {
let (content, left, right) = stack.removeLast()
if left == n && right == n {
result = content
} else {
if left < n {
stack.append((content + "(", left + 1, right))
}
if left > right {
stack.append((content + ")", left, right + 1))
}
}
}
return result
}
}
```class Solution { // invalid redeclaration of 'Solution'indirect enum HTMLNode {
case text(_ content: String)
case element(_ name: String, attributes: [String : String] = [:], children: [Self] = [])
}
func generate(_ tree: HTMLNode) -> String {
switch tree {
case let .text(content):
return content
case let .element(name, attributes, children):
var result = "<" + name
for (key, value) in attributes {
result += " " + key + "=\"" + value + "\""
}
result += ">"
for child in children {
result += generate(child)
}
result += "</" + name + ">"
return result
}
}
class Solution {
func generateParenthesis(_ n: Int) -> String {
guard n > 0 else {
return ""
}
return generate(n, n)
}
private func generate(_ left: Int, _ right: Int) -> String {
if left == 0 && right == 0 {
return ""
}
if left == right {
return "(" + generate(left - 1, right) + ")"
} else if left < right {
if left == 1 {
return "(" + generate(left, right - 1) + ")"
} else {
return generate(left - 1, right) + "(" + generate(left, right - 1) + ")"
}
}
return ""
}
}
class Solution {
func generateParenthesis(_ n: Int) -> String {
guard n > 0 else {
return ""
}
var result = [String]()
result.append("(")
while result.count > 0 {
let last = result.removeLast()
if last.count == 2 * n {
result.append(last + ")")
} else {
result.append(last + "(")
result.append(last + ")")
}
}
return result.removeLast()
}
}```swift
indirect enum HTMLNode {
case text(_ content: String)
case element(_ name: String, attributes: [String : String] = [:], children: [Self] = [])
}
// HTML generator from predefined elements tree.
// Output with standart HTML like this "<div><a href="swifteval"></a></div>"
func generate(_ tree: HTMLNode) -> String {
switch tree {
case let .text(content):
return content
case let .element(name, attributes, children):
var result = "<" + name
for (key, value) in attributes {
result += " " + key + "=\"" + value + "\""
}
result += ">"
for child in children {
result += generate(child)
}
result += "</" + name + ">"
return result
}
}
```
### 解法二：递归
```swift
class Solution {
func generateParenthesis(_ n: Int) -> String {
guard n > 0 else {
return ""
}
return generate(n, n)
}
private func generate(_ left: Int, _ right: Int) -> String {
if left == 0 && right == 0 {
return ""
}
if left == right {
return "(" + generate(left - 1, right) + ")"
} else if left < right {
if left == 1 {
return "(" + generate(left, right - 1) + ")"
} else {
return generate(left - 1, right) + "(" + generate(left, right - 1) + ")"
}
}
return ""
}
}
```
### 解法三：迭代
```swift
class Solution {
func generateParenthesis(_ n: Int) -> String {
guard n > 0 else {
return ""
}
var result = [String]()
result.append("(")
while result.count > 0 {
let last = result.removeLast()
if last.count == 2 * n {
result.append(last + ")")
} else {
result.append(last + "(")
result.append(last + ")")
}
}
return result.removeLast()
}
}
```class Solution { // invalid redeclaration of 'Solution'indirect enum HTMLNode {
case text(_ content: String)
case element(_ name: String, attributes: [String : String] = [:], children: [Self] = [])
}
func generate(_ tree: HTMLNode) -> String {
switch tree {
case .text(let content):
return content
case .element(let name, attributes: let attrs, children: let children):
var attrsString = ""
for (key, value) in attrs {
attrsString += " " + key + "=\"" + value + "\""
}
var childrenString = ""
for child in children {
childrenString += generate(child)
}
return "<" + name + attrsString + ">" + childrenString + "</" + name + ">"
}
}
class Solution {
func generateParenthesis(_ n: Int) -> String {
guard n > 0 else {
return ""
}
var result = ""
generate(n, n, result)
return result
}
private func generate(_ left: Int, _ right: Int, _ result: inout String) {
guard left > 0, right > 0 else {
return
}
guard left > right else {
result += ")"
generate(left - 1, right, &result)
result.removeLast()
}
result += "("
generate(left, right - 1, &result)
result.removeLast()
}
}```swift
indirect enum HTMLNode {
case text(_ content: String)
case element(_ name: String, attributes: [String : String] = [:], children: [Self] = [])
}
// HTML generator from predefined elements tree.
// Output with standart HTML like this "<div><a href="swifteval"></a></div>"
func generate(_ tree: HTMLNode) -> String {
switch tree {
case .text(let content):
return content
case .element(let name, attributes: let attrs, children: let children):
var attrsString = ""
for (key, value) in attrs {
attrsString += " " + key + "=\"" + value + "\""
}
var childrenString = ""
for child in children {
childrenString += generate(child)
}
return "<" + name + attrsString + ">" + childrenString + "</" + name + ">"
}
}
```
### 解题思路
递归生成HTML
### 代码
```swift
class Solution {
func generateParenthesis(_ n: Int) -> String {
guard n > 0 else {
return ""
}
var result = ""
generate(n, n, result)
return result
}
private func generate(_ left: Int, _ right: Int, _ result: inout String) {
guard left > 0, right > 0 else {
return
}
guard left > right else {
result += ")"
generate(left - 1, right, &result)
result.removeLast()
}
result += "("
generate(left, right - 1, &result)
result.removeLast()
}
}
```generate(n, n, result) // passing value of type 'String' to an inout parameter requires explicit '&'indirect enum HTMLNode {
case text(_ content: String)
case element(_ name: String, attributes: [String : String] = [:], children: [Self] = [])
}
func generate(_ tree: HTMLNode) -> String {
switch tree {
case .text(let content):
return content
case .element(let name, attributes: let attrs, children: let children):
var result = "<" + name
for (key, value) in attrs {
result += " " + key + "=\"" + value + "\""
}
result += ">"
for child in children {
result += generate(child)
}
result += "</" + name + ">"
return result
}
}```swift
indirect enum HTMLNode {
case text(_ content: String)
case element(_ name: String, attributes: [String : String] = [:], children: [Self] = [])
}
// HTML generator from predefined elements tree.
// Output with standart HTML like this "<div><a href="swifteval"></a></div>"
func generate(_ tree: HTMLNode) -> String {
switch tree {
case .text(let content):
return content
case .element(let name, attributes: let attrs, children: let children):
var result = "<" + name
for (key, value) in attrs {
result += " " + key + "=\"" + value + "\""
}
result += ">"
for child in children {
result += generate(child)
}
result += "</" + name + ">"
return result
}
}
```
### 解法二：递归
```swift
// HTML generator from predefined elements tree.
// Output with standart HTML like this "<div><a href="swifteval"></a></div>"
func generate(_ tree: HTMLNode) -> String {
switch tree {
case .text(let content):
return content
case .element(let name, attributes: let attrs, children: let children):
var result = "<" + name
for (key, value) in attrs {
result += " " + key + "=\"" + value + "\""
}
result += ">"
for child in children {
result += generate(child)
}
result += "</" + name + ">"
return result
}
}
```
### 解法三：递归
```swift
// HTML generator from predefined elements tree.
// Output with standart HTML like this "<div><a href="swifteval"></a></div>"
func generate(_ tree: HTMLNode) -> String {
switch tree {
case .text(let content):
return content
case .element(let name, attributes: let attrs, children: let children):
var result = "<" + name
for (key, value) in attrs {
result += " " + key + "=\"" + value + "\""
}
result += ">"
for child in children {
result += generate(child)
}
result += "</" + name + ">"
return result
}
}
```
### 解法四：递归
```swift
// HTML generator from predefined elements tree.
// Output with standart HTML like this "<div><a href="swifteval"></a></div>"
func generate(_ tree: HTMLNode) -> String {
switch tree {
case .text(let content):
return content
case .element(let name, attributes: let attrs, children: let children):
var result = "<" + name
for (key, value) in attrs {
result += " " + key + "=\"" + value + "\""
}
result += ">"
for child in children {
result += generate(child)
}
result += "</" + name + ">"
return result
}
}
```
### 解法五：递归
```swift
// HTML generator from predefined elements tree.
// Output with standart HTML like this "<div><a href="swifteval"></a></div>"
func generate(_ tree: HTMLNode) -> String {
switch tree {
case .text(let content):
return content
case .element(let name, attributes: let attrs, children: let children):
var result = "<" + name
for (key, value) in attrs {
result += " " + key + "=\"" + value + "\""
}
result += ">"
for child in children {
result += generate(child)
}
result += "</" + name + ">"
return result
}
}
```
### 解法六：递归
```swift
// HTML generator from predefined elements tree.
// Output with standart HTML like this "<div><a href="swifteval"></a></div>"
func generate(_ tree: HTMLNode) -> String {
switch tree {
case .text(let content):
return content
case .element(let name, attributes: let attrs, children: let children):
var result = "<" + name
for (key, value) in attrs {
result += " " + key +indirect enum HTMLNode {
case text(_ content: String)
case element(_ name: String, attributes: [String : String] = [:], children: [Self] = [])
}
func generate(_ tree: HTMLNode) -> String {
switch tree {
case .text(let content):
return content
case .element(let name, attributes: let attributes, children: let children):
var result = "<" + name
for (key, value) in attributes {
result += " " + key + "=\"" + value + "\""
}
result += ">"
for child in children {
result += generate(child)
}
result += "</" + name + ">"
return result
}
}
func generate(_ tree: HTMLNode, withPrefix: String = "") -> String {
switch tree {
case .text(let content):
return withPrefix + content
case .element(let name, attributes: let attributes, children: let children):
var result = withPrefix + "<" + name
for (key, value) in attributes {
result += " " + key + "=\"" + value + "\""
}
result += ">"
for child in children {
result += generate(child, withPrefix: withPrefix + " ")
}
result += "</" + name + ">"
return result
}
}```swift
indirect enum HTMLNode {
case text(_ content: String)
case element(_ name: String, attributes: [String : String] = [:], children: [Self] = [])
}
// HTML generator from predefined elements tree.
// Output with standart HTML like this "<div><a href="swifteval"></a></div>"
func generate(_ tree: HTMLNode) -> String {
switch tree {
case .text(let content):
return content
case .element(let name, attributes: let attributes, children: let children):
var result = "<" + name
for (key, value) in attributes {
result += " " + key + "=\"" + value + "\""
}
result += ">"
for child in children {
result += generate(child)
}
result += "</" + name + ">"
return result
}
}
// HTML generator from predefined elements tree.
// Output with HTML like this "<div><a href="swifteval"></a></div>"
func generate(_ tree: HTMLNode, withPrefix: String = "") -> String {
switch tree {
case .text(let content):
return withPrefix + content
case .element(let name, attributes: let attributes, children: let children):
var result = withPrefix + "<" + name
for (key, value) in attributes {
result += " " + key + "=\"" + value + "\""
}
result += ">"
for child in children {
result += generate(child, withPrefix: withPrefix + " ")
}
result += "</" + name + ">"
return result
}
}
// HTML generator from predefined elements tree.
// Output with HTML like this "<div><a href="swifteval"></a></div>"
func generate(_ tree: HTMLNode, withPrefix: String = "") -> String {
switch tree {
case .text(let content):
return withPrefix + content
case .element(let name, attributes: let attributes, children: let children):
var result = withPrefix + "<" + name
for (key, value) in attributes {
result += " " + key + "=\"" + value + "\""
}
result += ">"
for child in children {
result += generate(child, withPrefix: withPrefix + " ")
}
result += "</" + name + ">"
return result
}
}
// HTML generator from predefined elements tree.
// Output with HTML like this "<div><a href="swifteval"></a></div>"
func generate(_ tree: HTMLNode, withPrefix: String = "") -> String {
switch tree {
case .text(let content):
return withPrefix + content
case .element(let name, attributes: let attributes, children: let children):
var result = withPrefix + "<" + name
for (key, value) in attributes {
result += " " + key + "=\"" + value + "\""
}
result += ">"
for child in children {
result += generate(child, withPrefix: withPrefix + " ")
}
result += "</" + name + ">"
return result
}
}
// HTML generator from predefined elements tree.
// Output with HTML like this "<div><a href="swifteval"></a></div>"
func generate(_ tree: HTMLNode, withPrefix: String = "") -> String {
switch tree {
case .text(let content):
return withPrefix + content
case .element(let name, attributes: let attributes, children: let children):
var result = withPrefix + "<" + name
for (key, value) in attributes {
result += " " + key + "=\"" + value + "\""
}
result += ">"
for child in children {
result += generate(child, withPrefix: withPrefix + " ")
}
result += "</" + name + ">"
return result
}
}
// HTML generator from predefined elements tree.
// Output with HTML like this "<div><a href="swifteval"></a></div>"
func generate(_ tree: HTMLNode, withPrefix: String = "") -> String {
switch tree {
case .text(let content):
return withPrefix + content
case .element(let name, attributes: let attributes, children: let children):
var result = withPrefix + "<" + name
for (key, value) in attributes {
indirect enum HTMLNode {
case text(_ content: String)
case element(_ name: String, attributes: [String : String] = [:], children: [Self] = [])
}
func generate(_ tree: HTMLNode) -> String {
switch tree {
case .text(let content):
return content
case .element(let name, attributes: let attributes, children: let children):
var result = "<" + name
for (key, value) in attributes {
result += " " + key + "=\"" + value + "\""
}
result += ">"
for child in children {
result += generate(child)
}
result += "</" + name + ">"
return result
}
}```swift
indirect enum HTMLNode {
case text(_ content: String)
case element(_ name: String, attributes: [String : String] = [:], children: [Self] = [])
}
// HTML generator from predefined elements tree.
// Output with standart HTML like this "<div><a href="swifteval"></a></div>"
func generate(_ tree: HTMLNode) -> String {
switch tree {
case .text(let content):
return content
case .element(let name, attributes: let attributes, children: let children):
var result = "<" + name
for (key, value) in attributes {
result += " " + key + "=\"" + value + "\""
}
result += ">"
for child in children {
result += generate(child)
}
result += "</" + name + ">"
return result
}
}
```
### 递归
递归的思路，就是将问题拆解成子问题，然后将子问题的结果组合起来。
```swift
func generate(_ tree: HTMLNode) -> String {
switch tree {
case .text(let content):
return content
case .element(let name, attributes: let attributes, children: let children):
var result = "<" + name
for (key, value) in attributes {
result += " " + key + "=\"" + value + "\""
}
result += ">"
for child in children {
result += generate(child)
}
result += "</" + name + ">"
return result
}
}
```
### 递归 + 缓存
递归的思路，就是将问题拆解成子问题，然后将子问题的结果组合起来。
```swift
func generate(_ tree: HTMLNode) -> String {
switch tree {
case .text(let content):
return content
case .element(let name, attributes: let attributes, children: let children):
var result = "<" + name
for (key, value) in attributes {
result += " " + key + "=\"" + value + "\""
}
result += ">"
for child in children {
result += generate(child)
}
result += "</" + name + ">"
return result
}
}
// 缓存
var cache = [HTMLNode: String]()
func generate(_ tree: HTMLNode) -> String {
switch tree {
case .text(let content):
return content
case .element(let name, attributes: let attributes, children: let children):
var result = "<" + name
for (key, value) in attributes {
result += " " + key + "=\"" + value + "\""
}
result += ">"
for child in children {
result += generate(child)
}
result += "</" + name + ">"
return result
}
}
```
### 递归 + 缓存 + 闭包
递归的思路，就是将问题拆解成子问题，然后将子问题的结果组合起来。
```swift
func generate(_ tree: HTMLNode) -> String {
switch tree {
case .text(let content):
return content
case .element(let name, attributes: let attributes, children: let children):
var result = "<" + name
for (key, value) in attributes {
result += " " + key + "=\"" + value + "\""
}
result += ">"
for child in children {
result += generate(child)
}
result += "</" + name + ">"
return result
}
}
// 缓存
var cache = [HTMLNode: String]()
func generate(_ tree: HTMLNode) -> String {
switch tree {
case .text(let content):
return content
case .element(let name, attributes: let attributes, children: let children):
var result = "<" + name
for (key, value) in attributes {
result += " " + key + "=\"" + value + "\""
}
result += ">"
for child in children {
result += generate(child)
}
result += "</" + name + ">"
return result
}
}
// 闭包
let generate = { (tree: HTMLNode) -> String in
switch tree {
case .text(let content):
return content
case .element(let name, attributes: let attributes, children: let children):
var result = "<indirect enum HTMLNode {
case text(_ content: String)
case element(_ name: String, attributes: [String : String] = [:], children: [Self] = [])
}
func generate(_ tree: HTMLNode) -> String {
switch tree {
case .text(let content):
return content
case .element(let name, attributes: let attributes, children: let children):
var result = "<" + name
for (key, value) in attributes {
result += " " + key + "=\"" + value + "\""
}
result += ">"
for child in children {
result += generate(child)
}
result += "</" + name + ">"
return result
}
}```swift
indirect enum HTMLNode {
case text(_ content: String)
case element(_ name: String, attributes: [String : String] = [:], children: [Self] = [])
}
// HTML generator from predefined elements tree.
// Output with standart HTML like this "<div><a href="swifteval"></a></div>"
func generate(_ tree: HTMLNode) -> String {
switch tree {
case .text(let content):
return content
case .element(let name, attributes: let attributes, children: let children):
var result = "<" + name
for (key, value) in attributes {
result += " " + key + "=\"" + value + "\""
}
result += ">"
for child in children {
result += generate(child)
}
result += "</" + name + ">"
return result
}
}
```
### 解法二
```swift
// HTML generator from predefined elements tree.
// Output with standart HTML like this "<div><a href="swifteval"></a></div>"
func generate(_ tree: HTMLNode) -> String {
switch tree {
case .text(let content):
return content
case .element(let name, attributes: let attributes, children: let children):
var result = "<" + name
for (key, value) in attributes {
result += " " + key + "=\"" + value + "\""
}
result += ">"
for child in children {
result += generate(child)
}
result += "</" + name + ">"
return result
}
}
```
### 解法三
```swift
// HTML generator from predefined elements tree.
// Output with standart HTML like this "<div><a href="swifteval"></a></div>"
func generate(_ tree: HTMLNode) -> String {
switch tree {
case .text(let content):
return content
case .element(let name, attributes: let attributes, children: let children):
var result = "<" + name
for (key, value) in attributes {
result += " " + key + "=\"" + value + "\""
}
result += ">"
for child in children {
result += generate(child)
}
result += "</" + name + ">"
return result
}
}
```
### 解法四
```swift
// HTML generator from predefined elements tree.
// Output with standart HTML like this "<div><a href="swifteval"></a></div>"
func generate(_ tree: HTMLNode) -> String {
switch tree {
case .text(let content):
return content
case .element(let name, attributes: let attributes, children: let children):
var result = "<" + name
for (key, value) in attributes {
result += " " + key + "=\"" + value + "\""
}
result += ">"
for child in children {
result += generate(child)
}
result += "</" + name + ">"
return result
}
}
```
### 解法五
```swift
// HTML generator from predefined elements tree.
// Output with standart HTML like this "<div><a href="swifteval"></a></div>"
func generate(_ tree: HTMLNode) -> String {
switch tree {
case .text(let content):
return content
case .element(let name, attributes: let attributes, children: let children):
var result = "<" + name
for (key, value) in attributes {
result += " " + key + "=\"" + value + "\""
}
result += ">"
for child in children {
result += generate(child)
}
result += "</" + name + ">"
return result
}
}
```
### 解法六
```swift
// HTML generator from predefined elements tree.
// Output with standart HTML like this "<div><a href="swifteval"></a></div>"
func generate(_ tree: HTMLNode) -> String {
switch tree {
case .text(let content):
return content
case .element(let name, attributes: let attributes, children: let children):
var result = "<" + name
for (key, value) in attributes {
result += " " + key + "=\"" + value + "\""
}
result += ">"
for child in children {
resultindirect enum HTMLNode {
case text(_ content: String)
case element(_ name: String, attributes: [String : String] = [:], children: [Self] = [])
}
func generate(_ tree: HTMLNode) -> String {
switch tree {
case .text(let content):
return content
case .element(let name, attributes: let attrs, children: let children):
var result = "<" + name
for (key, value) in attrs {
result += " " + key + "=\"" + value + "\""
}
result += ">"
for child in children {
result += generate(child)
}
result += "</" + name + ">"
return result
}
}
enum HTMLNode {
case text(_ content: String)
case element(_ name: String, attributes: [String : String] = [:], children: [Self] = [])
}```swift
indirect enum HTMLNode {
case text(_ content: String)
case element(_ name: String, attributes: [String : String] = [:], children: [Self] = [])
}
// HTML generator from predefined elements tree.
// Output with standart HTML like this "<div><a href="swifteval"></a></div>"
func generate(_ tree: HTMLNode) -> String {
switch tree {
case .text(let content):
return content
case .element(let name, attributes: let attrs, children: let children):
var result = "<" + name
for (key, value) in attrs {
result += " " + key + "=\"" + value + "\""
}
result += ">"
for child in children {
result += generate(child)
}
result += "</" + name + ">"
return result
}
}
```
### 递归生成
```swift
enum HTMLNode {
case text(_ content: String)
case element(_ name: String, attributes: [String : String] = [:], children: [Self] = [])
}
// HTML generator from predefined elements tree.
// Output with standart HTML like this "<div><a href="swifteval"></a></div>"
func generate(_ tree: HTMLNode) -> String {
switch tree {
case .text(let content):
return content
case .element(let name, attributes: let attrs, children: let children):
var result = "<" + name
for (key, value) in attrs {
result += " " + key + "=\"" + value + "\""
}
result += ">"
for child in children {
result += generate(child)
}
result += "</" + name + ">"
return result
}
}
```
### 递归生成
```swift
enum HTMLNode {
case text(_ content: String)
case element(_ name: String, attributes: [String : String] = [:], children: [Self] = [])
}
// HTML generator from predefined elements tree.
// Output with standart HTML like this "<div><a href="swifteval"></a></div>"
func generate(_ tree: HTMLNode) -> String {
switch tree {
case .text(let content):
return content
case .element(let name, attributes: let attrs, children: let children):
var result = "<" + name
for (key, value) in attrs {
result += " " + key + "=\"" + value + "\""
}
result += ">"
for child in children {
result += generate(child)
}
result += "</" + name + ">"
return result
}
}
```
### 递归生成
```swift
enum HTMLNode {
case text(_ content: String)
case element(_ name: String, attributes: [String : String] = [:], children: [Self] = [])
}
// HTML generator from predefined elements tree.
// Output with standart HTML like this "<div><a href="swifteval"></a></div>"
func generate(_ tree: HTMLNode) -> String {
switch tree {
case .text(let content):
return content
case .element(let name, attributes: let attrs, children: let children):
var result = "<" + name
for (key, value) in attrs {
result += " " + key + "=\"" + value + "\""
}
result += ">"
for child in children {
result += generate(child)
}
result += "</" + name + ">"
return result
}
}
```
### 递归生成
```swift
enum HTMLNode {
case text(_ content: String)
case element(_ name: String, attributes: [String : String] = [:], children: [Self] = [])
}
// HTML generator from predefined elements tree.
// Output with standart HTML like this "<div><a href="swifteval"></a></div>"
func generate(_ tree: HTMLNode) -> String {
switch tree {
case .text(let content):
return content
case .element(let name, attributes: let attrs, children: let children):
var result = "<" + name
for (key, value) in attrs {
result += " " + key + "=\"" + value + "\""
}
result += ">"
enum CalculateError: Error {
case invalidInput
}
func calculate(_ string: String) throws -> Double {
let tokens = string.components(separatedBy: CharacterSet.decomposedUnicodeCharacters.inverted)
let stack = [Double]()
for token in tokens {
switch token {
case "+":
stack.append(stack.popLast()! + stack.popLast()!)
case "-":
stack.append(stack.popLast()! - stack.popLast()!)
case "*":
stack.append(stack.popLast()! * stack.popLast()!)
case "/":
stack.append(stack.popLast()! / stack.popLast()!)
case "(":
stack.append(stack.popLast()!)
case ")":
break
default:
let number = Double(token)
if number.isNaN || number.isInfinite {
throw CalculateError.ininput
}
stack.append(number)
}
}
return stack.popLast()!
}```swift
enum CalculateError: Error {
case invalidInput
}
// Calculator which supports operations from readable string format.
// Valid tokens is "+-*/()", example input is "2+2*2".
func calculate(_ string: String) throws -> Double {
let tokens = string.components(separatedBy: CharacterSet.decomposedUnicodeCharacters.inverted)
let stack = [Double]()
for token in tokens {
switch token {
case "+":
stack.append(stack.popLast()! + stack.popLast()!)
case "-":
stack.append(stack.popLast()! - stack.popLast()!)
case "*":
stack.append(stack.popLast()! * stack.popLast()!)
case "/":
stack.append(stack.popLast()! / stack.popLast()!)
case "(":
stack.append(stack.popLast()!)
case ")":
break
default:
let number = Double(token)
if number.isNaN || number.isInfinite {
throw CalculateError.ininput
}
stack.append(number)
}
}
return stack.popLast()!
}
```let tokens = string.components(separatedBy: CharacterSet.decomposedUnicodeCharacters.inverted) // type 'CharacterSet' has no member 'decomposedUnicodeCharacters'return stack.popLast()! // cannot use mutating member on immutable value: 'stack' is a 'let' constantenum CalculateError: Error {
case invalidInput
}
func calculate(_ string: String) throws -> Double {
let tokens = try tokenize(string)
let (result, _) = try evaluate(tokens)
return result
}
func tokenize(_ string: String) throws -> [Token] {
let tokens = try tokenizeWithoutParens(string)
let (_, tokens) = try evaluate(tokens)
return tokens
}
func tokenizeWithoutParens(_ string: String) throws -> [Token] {
var tokens = [Token]()
let scanner = Scanner(string)
while !scanner.isAtEnd {
let token = try scanner.nextToken()
switch token {
case .number(let value):
tokens.append(.number(value))
case .operator(let op):
tokens.append(.operator(op))
case .leftParenthesis:
tokens.append(.leftParenthesis)
case .rightParenthesis:
tokens.append(.rightParenthesis)
default:
throw CalculateError.invalidInput
}
}
return tokens
}
func evaluate(_ tokens: [Token]) throws -> (Double, [Token]) {
var stack = [Double]()
for token in tokens {
switch token {
case .number(let value):
stack.append(value)
case .operator(let op):
let right = stack.removeLast()
let left = stack.removeLast()
switch op {
case "+":
stack.append(left + right)
case "-":
stack.append(left - right)
case "*":
stack.append(left * right)
case "/":
stack.append(left / right)
default:
throw CalculateError.invalidInput
}
default:
throw CalculateError.invalidInput
}
}
guard let result = stack.last else {
throw CalculateError.invalidInput
}
return (result, [])
}```swift
enum CalculateError: Error {
case invalidInput
}
// Calculator which supports operations from readable string format.
// Valid tokens is "+-*/()", example input is "2+2*2".
func calculate(_ string: String) throws -> Double {
let tokens = try tokenize(string)
let (result, _) = try evaluate(tokens)
return result
}
// Tokenize string into list of tokens.
func tokenize(_ string: String) throws -> [Token] {
let tokens = try tokenizeWithoutParens(string)
let (_, tokens) = try evaluate(tokens)
return tokens
}
// Tokenize string into list of tokens, without parenthesis.
func tokenizeWithoutParens(_ string: String) throws -> [Token] {
var tokens = [Token]()
let scanner = Scanner(string)
while !scanner.isAtEnd {
let token = try scanner.nextToken()
switch token {
case .number(let value):
tokens.append(.number(value))
case .operator(let op):
tokens.append(.operator(op))
case .leftParenthesis:
tokens.append(.leftParenthesis)
case .rightParenthesis:
tokens.append(.rightParenthesis)
default:
throw CalculateError.invalidInput
}
}
return tokens
}
// Evaluate list of tokens.
func evaluate(_ tokens: [Token]) throws -> (Double, [Token]) {
var stack = [Double]()
for token in tokens {
switch token {
case .number(let value):
stack.append(value)
case .operator(let op):
let right = stack.removeLast()
let left = stack.removeLast()
switch op {
case "+":
stack.append(left + right)
case "-":
stack.append(left - right)
case "*":
stack.append(left * right)
case "/":
stack.append(left / right)
default:
throw CalculateError.invalidInput
}
default:
throw CalculateError.invalidInput
}
}
guard let result = stack.last else {
throw CalculateError.invalidInput
}
return (result, [])
}
```
### 解法二：递归
递归的思路是，将输入字符串拆分成多个子串，然后递归求解每个子串的值。
递归的终止条件是，如果输入字符串是空字符串，或者输入字符串中只包含数字，则返回输入字符串的值；否则，返回空字符串。
递归的函数定义是，输入一个字符串，返回该字符串的值。
递归的函数实现是，如果输入字符串是空字符串，或者输入字符串中只包含数字，则返回输入字符串的值；否则，返回空字符串。
递归的函数实现中，首先判断输入字符串是否为空，如果是空字符串，则返回0；否则，将输入字符串拆分成多个子串，然后递归求解每个子串的值，最后返回子串的值之和。
递归的函数实现中，拆分输入字符串的代码实现是，使用一个指针i，初始化为0。然后遍历输入字符串，直到遇到非数字字符，或者遍历到字符串末尾。如果遇到非数字字符，则将指针i设为当前指针i的前一个位置，然后将指针i之前的子串作为输入参数，调用递归函数求解子串的值；如果遍历到字符串末尾，则将指针i设为当前指针i的前一个位置，然后将指针i之前的子串作为输入参数，调用递归函数求解子串的值。
递归的函数实现中，求解子串的值的代码实现是，使用一个指针j，初始化为i。然后遍历输入字符串，直到遇到非数字字符，或者遍历到字符串末尾。如果遇到非数字字符，则将指针j设为当前指针j的前一个位置，然后将指针j之前的子串作为输入参数，调用递归函数求解子串的值；如果遍历到字符串末尾，则将指针j设为当前指针j的前一个位置，然后将指针j之前的子串作为输入参数，调用递归函数求解子串的值。
递归的函数实现中，将子串的值之和返回的代码func tokenize(_ string: String) throws -> [Token] { // cannot find type 'Token' in scopefunc tokenizeWithoutParens(_ string: String) throws -> [Token] { // cannot find type 'Token' in scopevar tokens = [Token]() // cannot find 'Token' in scopevar tokens = [Token]() // cannot call value of non-function type '[Any]'let scanner = Scanner(string) // missing argument label 'string:' in calltokens.append(.number(value)) // cannot infer contextual base in reference to member 'number'tokens.append(.operator(op)) // cannot infer contextual base in reference to member 'operator'tokens.append(.leftParenthesis) // cannot infer contextual base in reference to member 'leftParenthesis'tokens.append(.rightParenthesis) // cannot infer contextual base in reference to member 'rightParenthesis'func evaluate(_ tokens: [Token]) throws -> (Double, [Token]) { // cannot find type 'Token' in scopefunc evaluate(_ tokens: [Token]) throws -> (Double, [Token]) { // cannot find type 'Token' in scopeenum CalculateError: Error {
case invalidInput
}
func calculate(_ string: String) throws -> Double {
let tokens = string.components(separatedBy: CharacterSet.decomposedUnicodeCharacters.inverted)
var stack = [Double]()
for token in tokens {
switch token {
case "+":
let right = stack.removeLast()
let left = stack.removeLast()
stack.append(left + right)
case "-":
let right = stack.removeLast()
let left = stack.removeLast()
stack.append(left - right)
case "*":
let right = stack.removeLast()
let left = stack.removeLast()
stack.append(left * right)
case "/":
let right = stack.removeLast()
let left = stack.removeLast()
stack.append(left / right)
case "(":
stack.append(0)
case ")":
let right = stack.removeLast()
let left = stack.removeLast()
stack.append(left)
stack.append(right)
default:
let number = Double(token)
if number.isNaN || number.isInfinite {
throw CalculateError.invalidInput
}
stack.append(number)
}
}
return stack.removeLast()
}```swift
enum CalculateError: Error {
case invalidInput
}
// Calculator which supports operations from readable string format.
// Valid tokens is "+-*/()", example input is "2+2*2".
func calculate(_ string: String) throws -> Double {
let tokens = string.components(separatedBy: CharacterSet.decomposedUnicodeCharacters.inverted)
var stack = [Double]()
for token in tokens {
switch token {
case "+":
let right = stack.removeLast()
let left = stack.removeLast()
stack.append(left + right)
case "-":
let right = stack.removeLast()
let left = stack.removeLast()
stack.append(left - right)
case "*":
let right = stack.removeLast()
let left = stack.removeLast()
stack.append(left * right)
case "/":
let right = stack.removeLast()
let left = stack.removeLast()
stack.append(left / right)
case "(":
stack.append(0)
case ")":
let right = stack.removeLast()
let left = stack.removeLast()
stack.append(left)
stack.append(right)
default:
let number = Double(token)
if number.isNaN || number.isInfinite {
throw CalculateError.invalidInput
}
stack.append(number)
}
}
return stack.removeLast()
}
```let tokens = string.components(separatedBy: CharacterSet.decomposedUnicodeCharacters.inverted) // type 'CharacterSet' has no member 'decomposedUnicodeCharacters'enum CalculateError: Error {
case invalidInput
}
func calculate(_ string: String) throws -> Double {
let tokens = string.components(separatedBy: CharacterSet.decomposedUnicodeCharacters.inverted)
let stack = [Double]()
var lastOperator = ""
for token in tokens {
if token == "+" || token == "-" || token == "*" || token == "/" {
if lastOperator == "" {
lastOperator = token
} else if lastOperator == "+" {
stack.append(stack.removeLast() + stack.removeLast())
lastOperator = token
} else if lastOperator == "-" {
stack.append(stack.removeLast() - stack.removeLast())
lastOperator = token
} else if lastOperator == "*" {
stack.append(stack.removeLast() * stack.removeLast())
lastOperator = token
} else if lastOperator == "/" {
stack.append(stack.removeLast() / stack.removeLast())
lastOperator = token
}
} else if token == "(" {
stack.append(stack.removeLast())
lastOperator = "("
} else if token == ")" {
if lastOperator == "(" {
stack.append(stack.removeLast())
lastOperator = ""
} else {
stack.append(stack.removeLast() * stack.removeLast())
lastOperator = ""
}
} else {
if lastOperator == "" {
stack.append(Double(token)!)
} else {
stack.append(stack.removeLast() * Double(token)!)
}
}
}
if lastOperator != "" {
throw CalculateError.invalidInput
}
return stack.removeLast()
}```swift
enum CalculateError: Error {
case invalidInput
}
// Calculator which supports operations from readable string format.
// Valid tokens is "+-*/()", example input is "2+2*2".
func calculate(_ string: String) throws -> Double {
let tokens = string.components(separatedBy: CharacterSet.decomposedUnicodeCharacters.inverted)
let stack = [Double]()
var lastOperator = ""
for token in tokens {
if token == "+" || token == "-" || token == "*" || token == "/" {
if lastOperator == "" {
lastOperator = token
} else if lastOperator == "+" {
stack.append(stack.removeLast() + stack.removeLast())
lastOperator = token
} else if lastOperator == "-" {
stack.append(stack.removeLast() - stack.removeLast())
lastOperator = token
} else if lastOperator == "*" {
stack.append(stack.removeLast() * stack.removeLast())
lastOperator = token
} else if lastOperator == "/" {
stack.append(stack.removeLast() / stack.removeLast())
lastOperator = token
}
} else if token == "(" {
stack.append(stack.removeLast())
lastOperator = "("
} else if token == ")" {
if lastOperator == "(" {
stack.append(stack.removeLast())
lastOperator = ""
} else {
stack.append(stack.removeLast() * stack.removeLast())
lastOperator = ""
}
} else {
if lastOperator == "" {
stack.append(Double(token)!)
} else {
stack.append(stack.removeLast() * Double(token)!)
}
}
}
if lastOperator != "" {
throw CalculateError.invalidInput
}
return stack.removeLast()
}
```let tokens = string.components(separatedBy: CharacterSet.decomposedUnicodeCharacters.inverted) // type 'CharacterSet' has no member 'decomposedUnicodeCharacters'return stack.removeLast() // cannot use mutating member on immutable value: 'stack' is a 'let' constantenum CalculateError: Error {
case invalidInput
}
func calculate(_ string: String) throws -> Double {
let tokens = string.components(separatedBy: CharacterSet(charactersIn: "+-*/()"))
var stack = [Double]()
for token in tokens {
switch token {
case "+":
let right = stack.removeLast()
let left = stack.removeLast()
stack.append(left + right)
case "-":
let right = stack.removeLast()
let left = stack.removeLast()
stack.append(left - right)
case "*":
let right = stack.removeLast()
let left = stack.removeLast()
stack.append(left * right)
case "/":
let right = stack.removeLast()
let left = stack.removeLast()
stack.append(left / right)
case "(":
stack.append(0)
case ")":
let right = stack.removeLast()
let left = stack.removeLast()
stack.append(left)
stack.append(right)
default:
stack.append(Double(token) ?? 0)
}
}
guard let result = stack.last else {
throw CalculateError.invalidInput
}
return result
}
enum class CalculateError(val message: String) : Exception()
// Calculator which supports operations from readable string format.
// Valid tokens is "+-*/()", example input is "2+2*2".
@Throws(CalculateError::class)
fun calculate(string: String): Double {
val tokens = string.split("+-*/()")
val stack = mutableListOf<Double>()
for (token in tokens) {
when (token) {
"+" -> {
val right = stack.removeAt(stack.lastIndex)
val left = stack.removeAt(stack.lastIndex)
stack.add(left + right)
}
"-" -> {
val right = stack.removeAt(stack.lastIndex)
val left = stack.removeAt(stack.lastIndex)
stack.add(left - right)
}
"*" -> {
val right = stack.removeAt(stack.lastIndex)
val left = stack.removeAt(stack.lastIndex)
stack.add(left * right)
}
"/" -> {
val right = stack.removeAt(stack.lastIndex)
val left = stack.removeAt(stack.lastIndex)
stack.add(left / right)
}
"(" -> {
stack.add(0.0)
}
")" -> {
val right = stack.removeAt(stack.lastIndex)
val left = stack.removeAt(stack.lastIndex)
stack.add(left)
stack.add(right)
}
else -> {
stack.add(token.toDouble())
}
}
}
if (stack.size == 1) {
return stack.first()
}
throw CalculateError("Invalid input")
}```swift
enum CalculateError: Error {
case invalidInput
}
// Calculator which supports operations from readable string format.
// Valid tokens is "+-*/()", example input is "2+2*2".
func calculate(_ string: String) throws -> Double {
let tokens = string.components(separatedBy: CharacterSet(charactersIn: "+-*/()"))
var stack = [Double]()
for token in tokens {
switch token {
case "+":
let right = stack.removeLast()
let left = stack.removeLast()
stack.append(left + right)
case "-":
let right = stack.removeLast()
let left = stack.removeLast()
stack.append(left - right)
case "*":
let right = stack.removeLast()
let left = stack.removeLast()
stack.append(left * right)
case "/":
let right = stack.removeLast()
let left = stack.removeLast()
stack.append(left / right)
case "(":
stack.append(0)
case ")":
let right = stack.removeLast()
let left = stack.removeLast()
stack.append(left)
stack.append(right)
default:
stack.append(Double(token) ?? 0)
}
}
guard let result = stack.last else {
throw CalculateError.invalidInput
}
return result
}
```
```kotlin
enum class CalculateError(val message: String) : Exception()
// Calculator which supports operations from readable string format.
// Valid tokens is "+-*/()", example input is "2+2*2".
@Throws(CalculateError::class)
fun calculate(string: String): Double {
val tokens = string.split("+-*/()")
val stack = mutableListOf<Double>()
for (token in tokens) {
when (token) {
"+" -> {
val right = stack.removeAt(stack.lastIndex)
val left = stack.removeAt(stack.lastIndex)
stack.add(left + right)
}
"-" -> {
val right = stack.removeAt(stack.lastIndex)
val left = stack.removeAt(stack.lastIndex)
stack.add(left - right)
}
"*" -> {
val right = stack.removeAt(stack.lastIndex)
val left = stack.removeAt(stack.lastIndex)
stack.add(left * right)
}
"/" -> {
val right = stack.removeAt(stack.lastIndex)
val left = stack.removeAt(stack.lastIndex)
stack.add(left / right)
}
"(" -> {
stack.add(0.0)
}
")" -> {
val right = stack.removeAt(stack.lastIndex)
val left = stack.removeAt(stack.lastIndex)
stack.add(left)
stack.add(right)
}
else -> {
stack.add(token.toDouble())
}
}
}
if (stack.size == 1) {
return stack.first()
}
throw CalculateError("Invalid input")
}
```
```scala
// Calculator which supports operations from readable string format.
// Valid tokens is "+-*/()", example input is "2+2*2".
def calculate(string: String): Double = {
val tokens = string.split("+-*/()")
var stack = scala.collection.mutable.Stack[Double]()
for (token <- tokens) {
token match {
case "+" => {
val right = stack.pop()
val left = stack.pop()
stack.push(left + right)
}
case "-" => {
val right = stack.pop()
val left = stack.pop()
stack.push(left - right)
}
case "*" => {
val right = stack.pop()
val left = stack.pop()
stack.push(left * right)
}
case "/" => {
val right = stack.pop()
val left = stack.pop()
stack.push(left / right)
}
case "(" => {
stack.push(enum class CalculateError(val message: String) : Exception() // invalid redeclaration of 'CalculateError'enum class CalculateError(val message: String) : Exception() // expected '{' in classenum class CalculateError(val message: String) : Exception() // keyword 'class' cannot be used as an identifier hereenum CalculateError: Error {
case invalidInput
}
func calculate(_ string: String) throws -> Double {
let tokens = try tokenize(string)
let (result, _) = try evaluate(tokens)
return result
}
func tokenize(_ string: String) throws -> [Token] {
let tokens = [Token.Operator("+"), Token.Operator("-"), Token.Operator("*"), Token.Operator("/"), Token.Operator("("), Token.Operator(")")]
let operators = tokens.map { $0.operator }
let tokens = string.components(separatedBy: operators)
let tokenized = tokens.map { Token.Number(Double($0)!) }
return tokenized
}
func evaluate(_ tokens: [Token]) throws -> (result: Double, _: [Token]) {
var stack = [Double]()
var lastToken: Token? = nil
for token in tokens {
switch token {
case .Number(let value):
stack.append(value)
case .Operator(let operator):
if operator == "(" {
stack.append(0.0)
} else if operator == ")" {
let last = stack.removeLast()
while let lastOperator = lastToken, lastOperator.operator != "(" {
let result = operate(stack.removeLast(), lastOperator.operator, last)
stack.append(result)
}
stack.removeLast()
} else {
let last = stack.removeLast()
let result = operate(last, operator, stack.removeLast())
stack.append(result)
}
}
lastToken = token
}
guard let last = lastToken else {
return (0.0, [])
}
guard last.operator != "(" else {
throw CalculateError.invalidInput
}
let result = operate(stack.removeLast(), last.operator, stack.removeLast())
return (result, [])
}
func operate(_ left: Double, _ operator: String, _ right: Double) throws -> Double {
switch operator {
case "+":
return left + right
case "-":
return left - right
case "*":
return left * right
case "/":
guard right != 0 else {
throw CalculateError.invalidInput
}
return left / right
default:
throw CalculateError.invalidInput
}
}```swift
enum CalculateError: Error {
case invalidInput
}
// Calculator which supports operations from readable string format.
// Valid tokens is "+-*/()", example input is "2+2*2".
func calculate(_ string: String) throws -> Double {
let tokens = try tokenize(string)
let (result, _) = try evaluate(tokens)
return result
}
// Tokenize string into array of tokens.
// Invalid input will cause `CalculateError.invalidInput` error.
func tokenize(_ string: String) throws -> [Token] {
let tokens = [Token.Operator("+"), Token.Operator("-"), Token.Operator("*"), Token.Operator("/"), Token.Operator("("), Token.Operator(")")]
let operators = tokens.map { $0.operator }
let tokens = string.components(separatedBy: operators)
let tokenized = tokens.map { Token.Number(Double($0)!) }
return tokenized
}
// Evaluate tokens into result.
// Invalid input will cause `CalculateError.invalidInput` error.
func evaluate(_ tokens: [Token]) throws -> (result: Double, _: [Token]) {
var stack = [Double]()
var lastToken: Token? = nil
for token in tokens {
switch token {
case .Number(let value):
stack.append(value)
case .Operator(let operator):
if operator == "(" {
stack.append(0.0)
} else if operator == ")" {
let last = stack.removeLast()
while let lastOperator = lastToken, lastOperator.operator != "(" {
let result = operate(stack.removeLast(), lastOperator.operator, last)
stack.append(result)
}
stack.removeLast()
} else {
let last = stack.removeLast()
let result = operate(last, operator, stack.removeLast())
stack.append(result)
}
}
lastToken = token
}
guard let last = lastToken else {
return (0.0, [])
}
guard last.operator != "(" else {
throw CalculateError.invalidInput
}
let result = operate(stack.removeLast(), last.operator, stack.removeLast())
return (result, [])
}
// Operate two numbers with given operator.
// Invalid input will cause `CalculateError.invalidInput` error.
func operate(_ left: Double, _ operator: String, _ right: Double) throws -> Double {
switch operator {
case "+":
return left + right
case "-":
return left - right
case "*":
return left * right
case "/":
guard right != 0 else {
throw CalculateError.invalidInput
}
return left / right
default:
throw CalculateError.invalidInput
}
}
```func tokenize(_ string: String) throws -> [Token] { // cannot find type 'Token' in scopelet tokens = [Token.Operator("+"), Token.Operator("-"), Token.Operator("*"), Token.Operator("/"), Token.Operator("("), Token.Operator(")")] // cannot find 'Token' in scopelet tokens = [Token.Operator("+"), Token.Operator("-"), Token.Operator("*"), Token.Operator("/"), Token.Operator("("), Token.Operator(")")] // cannot find 'Token' in scopelet tokens = [Token.Operator("+"), Token.Operator("-"), Token.Operator("*"), Token.Operator("/"), Token.Operator("("), Token.Operator(")")] // cannot find 'Token' in scopelet tokens = [Token.Operator("+"), Token.Operator("-"), Token.Operator("*"), Token.Operator("/"), Token.Operator("("), Token.Operator(")")] // cannot find 'Token' in scopelet tokens = [Token.Operator("+"), Token.Operator("-"), Token.Operator("*"), Token.Operator("/"), Token.Operator("("), Token.Operator(")")] // cannot find 'Token' in scopelet tokens = [Token.Operator("+"), Token.Operator("-"), Token.Operator("*"), Token.Operator("/"), Token.Operator("("), Token.Operator(")")] // cannot find 'Token' in scopelet tokenized = tokens.map { Token.Number(Double($0)!) } // cannot find 'Token' in scopefunc evaluate(_ tokens: [Token]) throws -> (result: Double, _: [Token]) { // cannot find type 'Token' in scopefunc evaluate(_ tokens: [Token]) throws -> (result: Double, _: [Token]) { // cannot find type 'Token' in scopevar lastToken: Token? = nil // cannot find type 'Token' in scopecase .Operator(let operator): // expected patterncase .Operator(let operator): // expected ':' after 'case'case .Operator(let operator): // ')' is not allowed in operator namesif operator == "(" { // operator must be declared as 'prefix', 'postfix', or 'infix'if operator == "(" { // expected expression, var, or let in 'if' conditionif operator == "(" { // 'operator' may only be declared at file scope} else if operator == ")" { // operator must be declared as 'prefix', 'postfix', or 'infix'} else if operator == ")" { // expected expression, var, or let in 'if' condition} else if operator == ")" { // 'operator' may only be declared at file scopeswitch operator { // expected operator name in operator declarationswitch operator { // expected expression in 'switch' statementenum CalculateError: Error {
case invalidInput
}
func calculate(_ string: String) throws -> Double {
let tokens = string.components(separatedBy: CharacterSet(charactersIn: "+-*/()"))
var stack = [Double]()
for token in tokens {
switch token {
case "+":
let right = stack.removeLast()
let left = stack.removeLast()
stack.append(left + right)
case "-":
let right = stack.removeLast()
let left = stack.removeLast()
stack.append(left - right)
case "*":
let right = stack.removeLast()
let left = stack.removeLast()
stack.append(left * right)
case "/":
let right = stack.removeLast()
let left = stack.removeLast()
stack.append(left / right)
case "(":
stack.append(0)
case ")":
while let last = stack.last, last != 0 {
stack.removeLast()
let right = stack.removeLast()
let left = stack.removeLast()
stack.append(left + right)
}
stack.removeLast()
default:
let number = Double(token)
if number.isNaN {
throw CalculateError.invalidInput
}
stack.append(number)
}
}
return stack.removeLast()
}```swift
enum CalculateError: Error {
case invalidInput
}
// Calculator which supports operations from readable string format.
// Valid tokens is "+-*/()", example input is "2+2*2".
func calculate(_ string: String) throws -> Double {
let tokens = string.components(separatedBy: CharacterSet(charactersIn: "+-*/()"))
var stack = [Double]()
for token in tokens {
switch token {
case "+":
let right = stack.removeLast()
let left = stack.removeLast()
stack.append(left + right)
case "-":
let right = stack.removeLast()
let left = stack.removeLast()
stack.append(left - right)
case "*":
let right = stack.removeLast()
let left = stack.removeLast()
stack.append(left * right)
case "/":
let right = stack.removeLast()
let left = stack.removeLast()
stack.append(left / right)
case "(":
stack.append(0)
case ")":
while let last = stack.last, last != 0 {
stack.removeLast()
let right = stack.removeLast()
let left = stack.removeLast()
stack.append(left + right)
}
stack.removeLast()
default:
let number = Double(token)
if number.isNaN {
throw CalculateError.invalidInput
}
stack.append(number)
}
}
return stack.removeLast()
}
```if number.isNaN { // value of optional type 'Double?' must be unwrapped to refer to member 'isNaN' of wrapped base type 'Double'stack.append(number) // value of optional type 'Double?' must be unwrapped to a value of type 'Double'enum CalculateError: Error {
case invalidInput
}
func calculate(_ string: String) throws -> Double {
let tokens = string.components(separatedBy: CharacterSet.decomposedUnicodeCharacters.inverted)
var stack = [Double]()
for token in tokens {
if token.count == 0 {
continue
}
if token.count == 1 {
if token == "+" {
stack.append(stack.popLast()! + stack.popLast()!)
} else if token == "-" {
stack.append(stack.popLast()! - stack.popLast()!)
} else if token == "*" {
stack.append(stack.popLast()! * stack.popLast()!)
} else if token == "/" {
stack.append(stack.popLast()! / stack.popLast()!)
} else {
throw CalculateError.invalidInput
}
} else {
if token.hasPrefix("0x") {
stack.append(Double(from: String(token.dropFirst(2)))!)
} else {
stack.append(Double(from: token)!)
}
}
}
return stack.popLast()!
}
func calculate(_ string: String) throws -> Double {
let tokens = string.components(separatedBy: CharacterSet.decomposedUnicodeCharacters.inverted)
return calculate(tokens, 0, tokens.count - 1)
}
func calculate(_ tokens: [String], _ start: Int, _ end: Int) throws -> Double {
if start == end {
return Double(from: tokens[start])!
}
let token = tokens[start]
if token.count == 0 {
return 0
}
if token.count == 1 {
if token == "+" {
return calculate(tokens, start + 1, end - 1) + calculate(tokens, start + 2, end)
} else if token == "-" {
return calculate(tokens, start + 1, end - 1) - calculate(tokens, start + 2, end)
} else if token == "*" {
return calculate(tokens, start + 1, end - 1) * calculate(tokens, start + 2, end)
} else if token == "/" {
return calculate(tokens, start + 1, end - 1) / calculate(tokens, start + 2, end)
} else {
throw CalculateError.invalidInput
}
} else {
if token.hasPrefix("0x") {
return Double(from: String(token.dropFirst(2)))!
} else {
return Double(from: token)!
}
}
}```swift
enum CalculateError: Error {
case invalidInput
}
// Calculator which supports operations from readable string format.
// Valid tokens is "+-*/()", example input is "2+2*2".
func calculate(_ string: String) throws -> Double {
let tokens = string.components(separatedBy: CharacterSet.decomposedUnicodeCharacters.inverted)
var stack = [Double]()
for token in tokens {
if token.count == 0 {
continue
}
if token.count == 1 {
if token == "+" {
stack.append(stack.popLast()! + stack.popLast()!)
} else if token == "-" {
stack.append(stack.popLast()! - stack.popLast()!)
} else if token == "*" {
stack.append(stack.popLast()! * stack.popLast()!)
} else if token == "/" {
stack.append(stack.popLast()! / stack.popLast()!)
} else {
throw CalculateError.invalidInput
}
} else {
if token.hasPrefix("0x") {
stack.append(Double(from: String(token.dropFirst(2)))!)
} else {
stack.append(Double(from: token)!)
}
}
}
return stack.popLast()!
}
```
### 解法二：递归
```swift
enum CalculateError: Error {
case invalidInput
}
// Calculator which supports operations from readable string format.
// Valid tokens is "+-*/()", example input is "2+2*2".
func calculate(_ string: String) throws -> Double {
let tokens = string.components(separatedBy: CharacterSet.decomposedUnicodeCharacters.inverted)
return calculate(tokens, 0, tokens.count - 1)
}
func calculate(_ tokens: [String], _ start: Int, _ end: Int) throws -> Double {
if start == end {
return Double(from: tokens[start])!
}
let token = tokens[start]
if token.count == 0 {
return 0
}
if token.count == 1 {
if token == "+" {
return calculate(tokens, start + 1, end - 1) + calculate(tokens, start + 2, end)
} else if token == "-" {
return calculate(tokens, start + 1, end - 1) - calculate(tokens, start + 2, end)
} else if token == "*" {
return calculate(tokens, start + 1, end - 1) * calculate(tokens, start + 2, end)
} else if token == "/" {
return calculate(tokens, start + 1, end - 1) / calculate(tokens, start + 2, end)
} else {
throw CalculateError.invalidInput
}
} else {
if token.hasPrefix("0x") {
return Double(from: String(token.dropFirst(2)))!
} else {
return Double(from: token)!
}
}
}
```
### 解法三：栈
```swift
enum CalculateError: Error {
case invalidInput
}
// Calculator which supports operations from readable string format.
// Valid tokens is "+-*/()", example input is "2+2*2".
func calculate(_ string: String) throws -> Double {
let tokens = string.components(separatedBy: CharacterSet.decomposedUnicodeCharacters.inverted)
var stack = [Double]()
for token in tokens {
if token.count == 0 {
continue
}
if token.count == 1 {
if token == "+" {
stack.append(stack.popLast()! + stack.popLast()!)
} else if token == "-" {
stack.append(stack.popLast()! - stack.popLast()!)
} else if token == "*" {
stack.append(stack.popLast()! * stack.popLast()!)
} else if token == "/" {
stack.append(stack.popLast()! / stack.popLast()!)
} else {
throw CalculateError.invalidInput
}
} else {
if tokenlet tokens = string.components(separatedBy: CharacterSet.decomposedUnicodeCharacters.inverted) // type 'CharacterSet' has no member 'decomposedUnicodeCharacters'func calculate(_ string: String) throws -> Double { // invalid redeclaration of 'calculate'let tokens = string.components(separatedBy: CharacterSet.decomposedUnicodeCharacters.inverted) // type 'CharacterSet' has no member 'decomposedUnicodeCharacters'return Double(from: tokens[start])! // cannot force unwrap value of non-optional type 'Double'return Double(from: tokens[start])! // argument type 'String' does not conform to expected type 'Decoder'return calculate(tokens, start + 1, end - 1) + calculate(tokens, start + 2, end) // call can throw but is not marked with 'try'return calculate(tokens, start + 1, end - 1) + calculate(tokens, start + 2, end) // call can throw but is not marked with 'try'return calculate(tokens, start + 1, end - 1) - calculate(tokens, start + 2, end) // call can throw but is not marked with 'try'return calculate(tokens, start + 1, end - 1) - calculate(tokens, start + 2, end) // call can throw but is not marked with 'try'return calculate(tokens, start + 1, end - 1) * calculate(tokens, start + 2, end) // call can throw but is not marked with 'try'return calculate(tokens, start + 1, end - 1) * calculate(tokens, start + 2, end) // call can throw but is not marked with 'try'return calculate(tokens, start + 1, end - 1) / calculate(tokens, start + 2, end) // call can throw but is not marked with 'try'return calculate(tokens, start + 1, end - 1) / calculate(tokens, start + 2, end) // call can throw but is not marked with 'try'return Double(from: String(token.dropFirst(2)))! // argument type 'String' does not conform to expected type 'Decoder'return Double(from: String(token.dropFirst(2)))! // cannot force unwrap value of non-optional type 'Double'return Double(from: token)! // argument type 'String' does not conform to expected type 'Decoder'return Double(from: token)! // cannot force unwrap value of non-optional type 'Double'enum CalculateError: Error {
case invalidInput
}
func calculate(_ string: String) throws -> Double {
let tokens = string.components(separatedBy: CharacterSet.decomposedUnicodeCharacters.inverted)
var stack = [Double]()
for token in tokens {
switch token {
case "+":
stack.append(stack.popLast()! + stack.popLast()!)
case "-":
stack.append(stack.popLast()! - stack.popLast()!)
case "*":
stack.append(stack.popLast()! * stack.popLast()!)
case "/":
stack.append(stack.popLast()! / stack.popLast()!)
default:
if let number = Double(token) {
stack.append(number)
} else {
throw CalculateError.invalidInput
}
}
}
return stack.popLast()!
}
func calculate(_ string: String) throws -> Double {
let regex = try! NSRegularExpression(pattern: "\\d+|\\+|\\-|\\*|\\/|\\(|\\)")
let tokens = regex.matches(in: string, options: [], range: NSRange(string.startIndex..., in: string)).map { string[Range($0, in: string)] }
var stack = [Double]()
for token in tokens {
switch token {
case "+":
stack.append(stack.popLast()! + stack.popLast()!)
case "-":
stack.append(stack.popLast()! - stack.popLast()!)
case "*":
stack.append(stack.popLast()! * stack.popLast()!)
case "/":
stack.append(stack.popLast()! / stack.popLast()!)
default:
if let number = Double(token) {
stack.append(number)
} else {
throw CalculateError.invalidInput
}
}
}
return stack.popLast()!
}
func calculate(_ string: String) throws -> Double {
let tokens = string.components(separatedBy: CharacterSet.decomposedUnicodeCharacters.inverted)
return calculate(tokens)
}
func calculate(_ tokens: [String]) -> Double {
if tokens.count == 1 {
return Double(tokens[0])!
}
let op = tokens[0]
let num1 = calculate(Array(tokens[1..<tokens.count - 1]))
let num2 = calculate(Array(tokens[tokens.count - 1]))
switch op {
case "+":
return num1 + num2
case "-":
return num1 - num2
case "*":
return num1 * num2
case "/":
return num1 / num2
default:
throw CalculateError.invalidInput
}
}```swift
enum CalculateError: Error {
case invalidInput
}
// Calculator which supports operations from readable string format.
// Valid tokens is "+-*/()", example input is "2+2*2".
func calculate(_ string: String) throws -> Double {
let tokens = string.components(separatedBy: CharacterSet.decomposedUnicodeCharacters.inverted)
var stack = [Double]()
for token in tokens {
switch token {
case "+":
stack.append(stack.popLast()! + stack.popLast()!)
case "-":
stack.append(stack.popLast()! - stack.popLast()!)
case "*":
stack.append(stack.popLast()! * stack.popLast()!)
case "/":
stack.append(stack.popLast()! / stack.popLast()!)
default:
if let number = Double(token) {
stack.append(number)
} else {
throw CalculateError.invalidInput
}
}
}
return stack.popLast()!
}
```
### 解法二：正则表达式
```swift
enum CalculateError: Error {
case invalidInput
}
// Calculator which supports operations from readable string format.
// Valid tokens is "+-*/()", example input is "2+2*2".
func calculate(_ string: String) throws -> Double {
let regex = try! NSRegularExpression(pattern: "\\d+|\\+|\\-|\\*|\\/|\\(|\\)")
let tokens = regex.matches(in: string, options: [], range: NSRange(string.startIndex..., in: string)).map { string[Range($0, in: string)] }
var stack = [Double]()
for token in tokens {
switch token {
case "+":
stack.append(stack.popLast()! + stack.popLast()!)
case "-":
stack.append(stack.popLast()! - stack.popLast()!)
case "*":
stack.append(stack.popLast()! * stack.popLast()!)
case "/":
stack.append(stack.popLast()! / stack.popLast()!)
default:
if let number = Double(token) {
stack.append(number)
} else {
throw CalculateError.invalidInput
}
}
}
return stack.popLast()!
}
```
### 解法三：递归
```swift
enum CalculateError: Error {
case invalidInput
}
// Calculator which supports operations from readable string format.
// Valid tokens is "+-*/()", example input is "2+2*2".
func calculate(_ string: String) throws -> Double {
let tokens = string.components(separatedBy: CharacterSet.decomposedUnicodeCharacters.inverted)
return calculate(tokens)
}
func calculate(_ tokens: [String]) -> Double {
if tokens.count == 1 {
return Double(tokens[0])!
}
let op = tokens[0]
let num1 = calculate(Array(tokens[1..<tokens.count - 1]))
let num2 = calculate(Array(tokens[tokens.count - 1]))
switch op {
case "+":
return num1 + num2
case "-":
return num1 - num2
case "*":
return num1 * num2
case "/":
return num1 / num2
default:
throw CalculateError.invalidInput
}
}
```let tokens = string.components(separatedBy: CharacterSet.decomposedUnicodeCharacters.inverted) // type 'CharacterSet' has no member 'decomposedUnicodeCharacters'func calculate(_ string: String) throws -> Double { // invalid redeclaration of 'calculate'let tokens = regex.matches(in: string, options: [], range: NSRange(string.startIndex..., in: string)).map { string[Range($0, in: string)] } // value of optional type 'Range<String.Index>?' must be unwrapped to a value of type 'Range<String.Index>'let tokens = regex.matches(in: string, options: [], range: NSRange(string.startIndex..., in: string)).map { string[Range($0, in: string)] } // initializer 'init(_:in:)' requires that 'NSTextCheckingResult' conform to 'RangeExpression'func calculate(_ string: String) throws -> Double { // invalid redeclaration of 'calculate'let tokens = string.components(separatedBy: CharacterSet.decomposedUnicodeCharacters.inverted) // type 'CharacterSet' has no member 'decomposedUnicodeCharacters'let num2 = calculate(Array(tokens[tokens.count - 1])) // no exact matches in call to initializerthrow CalculateError.invalidInput // error is not handled because the enclosing function is not declared 'throws'enum CalculateError: Error {
case invalidInput
}
func calculate(_ string: String) throws -> Double {
let tokens = try tokenize(string)
let result = try evaluate(tokens)
return result
}
func tokenize(_ string: String) throws -> [Token] {
let characters = Array(string)
var tokens = [Token]()
var current = ""
for char in characters {
if char.isNumber {
current += char
} else if char == "+" {
tokens.append(Token(.plus, Double(current) ?? 0))
current = ""
} else if char == "-" {
tokens.append(Token(.minus, Double(current) ?? 0))
current = ""
} else if char == "*" {
tokens.append(Token(.multiply, Double(current) ?? 0))
current = ""
} else if char == "/" {
tokens.append(Token(.divide, Double(current) ?? 0))
current = ""
} else if char == "(" {
tokens.append(Token(.leftParenthesis, Double(current) ?? 0))
current = ""
} else if char == ")" {
tokens.append(Token(.rightParenthesis, Double(current) ?? 0))
current = ""
} else {
throw CalculateError.invalidInput
}
}
if !current.isEmpty {
tokens.append(Token(.number, Double(current) ?? 0))
}
return tokens
}
func evaluate(_ tokens: [Token]) throws -> Double {
var stack = [Double]()
for token in tokens {
switch token {
case .number:
stack.append(token.value)
case .plus:
let second = stack.removeLast()
let first = stack.removeLast()
stack.append(first + second)
case .minus:
let second = stack.removeLast()
let first = stack.removeLast()
stack.append(first - second)
case .multiply:
let second = stack.removeLast()
let first = stack.removeLast()
stack.append(first * second)
case .divide:
let second = stack.removeLast()
let first = stack.removeLast()
stack.append(first / second)
case .leftParenthesis:
stack.append(0)
case .rightParenthesis:
let second = stack.removeLast()
let first = stack.removeLast()
stack.append(first * second)
}
}
return stack.removeLast()
}
enum Token {
case number(Double)
case plus
case minus
case multiply
case divide
case leftParenthesis
case rightParenthesis
}```swift
enum CalculateError: Error {
case invalidInput
}
// Calculator which supports operations from readable string format.
// Valid tokens is "+-*/()", example input is "2+2*2".
func calculate(_ string: String) throws -> Double {
let tokens = try tokenize(string)
let result = try evaluate(tokens)
return result
}
// Tokenize string into array of tokens.
func tokenize(_ string: String) throws -> [Token] {
let characters = Array(string)
var tokens = [Token]()
var current = ""
for char in characters {
if char.isNumber {
current += char
} else if char == "+" {
tokens.append(Token(.plus, Double(current) ?? 0))
current = ""
} else if char == "-" {
tokens.append(Token(.minus, Double(current) ?? 0))
current = ""
} else if char == "*" {
tokens.append(Token(.multiply, Double(current) ?? 0))
current = ""
} else if char == "/" {
tokens.append(Token(.divide, Double(current) ?? 0))
current = ""
} else if char == "(" {
tokens.append(Token(.leftParenthesis, Double(current) ?? 0))
current = ""
} else if char == ")" {
tokens.append(Token(.rightParenthesis, Double(current) ?? 0))
current = ""
} else {
throw CalculateError.invalidInput
}
}
if !current.isEmpty {
tokens.append(Token(.number, Double(current) ?? 0))
}
return tokens
}
// Evaluate tokens into result.
func evaluate(_ tokens: [Token]) throws -> Double {
var stack = [Double]()
for token in tokens {
switch token {
case .number:
stack.append(token.value)
case .plus:
let second = stack.removeLast()
let first = stack.removeLast()
stack.append(first + second)
case .minus:
let second = stack.removeLast()
let first = stack.removeLast()
stack.append(first - second)
case .multiply:
let second = stack.removeLast()
let first = stack.removeLast()
stack.append(first * second)
case .divide:
let second = stack.removeLast()
let first = stack.removeLast()
stack.append(first / second)
case .leftParenthesis:
stack.append(0)
case .rightParenthesis:
let second = stack.removeLast()
let first = stack.removeLast()
stack.append(first * second)
}
}
return stack.removeLast()
}
// Token type.
enum Token {
case number(Double)
case plus
case minus
case multiply
case divide
case leftParenthesis
case rightParenthesis
}
```current += char // cannot convert value of type 'String.Element' (aka 'Character') to expected argument type 'String'tokens.append(Token(.plus, Double(current) ?? 0)) // cannot infer contextual base in reference to member 'plus'tokens.append(Token(.plus, Double(current) ?? 0)) // 'Token' cannot be constructed because it has no accessible initializerstokens.append(Token(.minus, Double(current) ?? 0)) // cannot infer contextual base in reference to member 'minus'tokens.append(Token(.minus, Double(current) ?? 0)) // 'Token' cannot be constructed because it has no accessible initializerstokens.append(Token(.multiply, Double(current) ?? 0)) // 'Token' cannot be constructed because it has no accessible initializerstokens.append(Token(.multiply, Double(current) ?? 0)) // cannot infer contextual base in reference to member 'multiply'tokens.append(Token(.divide, Double(current) ?? 0)) // cannot infer contextual base in reference to member 'divide'tokens.append(Token(.divide, Double(current) ?? 0)) // 'Token' cannot be constructed because it has no accessible initializerstokens.append(Token(.leftParenthesis, Double(current) ?? 0)) // cannot infer contextual base in reference to member 'leftParenthesis'tokens.append(Token(.leftParenthesis, Double(current) ?? 0)) // 'Token' cannot be constructed because it has no accessible initializerstokens.append(Token(.rightParenthesis, Double(current) ?? 0)) // 'Token' cannot be constructed because it has no accessible initializerstokens.append(Token(.rightParenthesis, Double(current) ?? 0)) // cannot infer contextual base in reference to member 'rightParenthesis'tokens.append(Token(.number, Double(current) ?? 0)) // 'Token' cannot be constructed because it has no accessible initializerstokens.append(Token(.number, Double(current) ?? 0)) // cannot infer contextual base in reference to member 'number'stack.append(token.value) // value of type 'Token' has no member 'value'func execute(binary: String, arguments: [String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var out = ""
var err = ""
var outLine = ""
var errLine = ""
while let outLine = task.standardOutput.readline() {
outLine = String(outLine)
out += outLine
}
while let errLine = task.standardError.readline() {
errLine = String(errLine)
err += errLine
}
return (out, err)
}
func execute(binary: String, arguments: [String], environment: [String: String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var out = ""
var err = ""
var outLine = ""
var errLine = ""
while let outLine = task.standardOutput.readline() {
outLine = String(outLine)
out += outLine
}
while let errLine = task.standardError.readline() {
errLine = String(errLine)
err += errLine
}
return (out, err)
}
func execute(binary: String, arguments: [String], environment: [String: String], workingDirectory: String) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var out = ""
var err = ""
var outLine = ""
var errLine = ""
while let outLine = task.standardOutput.readline() {
outLine = String(outLine)
out += outLine
}
while let errLine = task.standardError.readline() {
errLine = String(errLine)
err += errLine
}
return (out, err)
}```swift
// Function to execute binary with arguments.
// Returns tuple where first element is stdout and second is stderr.
func execute(binary: String, arguments: [String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var out = ""
var err = ""
var outLine = ""
var errLine = ""
while let outLine = task.standardOutput.readline() {
outLine = String(outLine)
out += outLine
}
while let errLine = task.standardError.readline() {
errLine = String(errLine)
err += errLine
}
return (out, err)
}
// Function to execute binary with arguments.
// Returns tuple where first element is stdout and second is stderr.
func execute(binary: String, arguments: [String], environment: [String: String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var out = ""
var err = ""
var outLine = ""
var errLine = ""
while let outLine = task.standardOutput.readline() {
outLine = String(outLine)
out += outLine
}
while let errLine = task.standardError.readline() {
errLine = String(errLine)
err += errLine
}
return (out, err)
}
// Function to execute binary with arguments.
// Returns tuple where first element is stdout and second is stderr.
func execute(binary: String, arguments: [String], environment: [String: String], workingDirectory: String) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var out = ""
var err = ""
var outLine = ""
var errLine = ""
while let outLine = task.standardOutput.readline() {
outLine = String(outLine)
out += outLine
}
while let errLine = task.standardError.readline() {
errLine = String(errLine)
err += errLine
}
return (out, err)
}
```
### 参考
- [Swift での Process の使い方](https://qiita.com/kosuke/items/1437413b1339b5420296)
- [Swift での Process の使い方（2）](https://qiita.com/kosuke/items/1437413b1339b5420296)
- [Swift での Process の使い方（3）](https://qiita.com/kosuke/items/1437413b1339b5420296)
- [Swift での Process の使い方（4）](https://qiita.com/kosuke/items/1437413b1339b5420296)
- [Swift での Process の使い方（5）](https://qiita.com/kosuke/items/1437413b1339b5420296)
- [Swift での Process の使い方（6）](https://qiita.com/kosuke/items/1437413b1339b5420296)
- [Swift での Process の使い方（7）](https://qiita.com/kosuke/items/1437413b1339b5420296)
- [Swift での Process の使い方（8）](https://qiita.com/kosuke/items/1437413b1339b5420296)
- [Swift での Process の使い方（9）](https://qiita.com/kosuke/items/1437while let outLine = task.standardOutput.readline() { // value of type 'Any?' has no member 'readline'while let errLine = task.standardError.readline() { // value of type 'Any?' has no member 'readline'while let outLine = task.standardOutput.readline() { // value of type 'Any?' has no member 'readline'while let errLine = task.standardError.readline() { // value of type 'Any?' has no member 'readline'while let outLine = task.standardOutput.readline() { // value of type 'Any?' has no member 'readline'while let errLine = task.standardError.readline() { // value of type 'Any?' has no member 'readline'func execute(binary: String, arguments: [String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var stdout = ""
var stderr = ""
let outErr = [
"stdout",
"stderr"
]
for e in outErr {
let pipe = Pipe()
let file = pipe.fileHandleForReading
task.standardOutput = pipe
task.standardError = pipe
file.readToEndOfFileInBackground(block: { (data: NSData) in
stdout = NSString(data: data, encoding: String.Encoding.utf8.rawValue) as String
})
file.readToEndOfFileInBackground(block: { (data: NSData) in
stderr = NSString(data: data, encoding: String.Encoding.utf8.rawValue) as String
})
}
task.waitUntilExit()
return (stdout, stderr)
}```swift
// Function to execute binary with arguments.
// Returns tuple where first element is stdout and second is stderr.
func execute(binary: String, arguments: [String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var stdout = ""
var stderr = ""
let outErr = [
"stdout",
"stderr"
]
for e in outErr {
let pipe = Pipe()
let file = pipe.fileHandleForReading
task.standardOutput = pipe
task.standardError = pipe
file.readToEndOfFileInBackground(block: { (data: NSData) in
stdout = NSString(data: data, encoding: String.Encoding.utf8.rawValue) as String
})
file.readToEndOfFileInBackground(block: { (data: NSData) in
stderr = NSString(data: data, encoding: String.Encoding.utf8.rawValue) as String
})
}
task.waitUntilExit()
return (stdout, stderr)
}
```
### 2.2. 执行命令
```swift
// Function to execute binary with arguments.
// Returns tuple where first element is stdout and second is stderr.
func execute(binary: String, arguments: [String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var stdout = ""
var stderr = ""
let outErr = [
"stdout",
"stderr"
]
for e in outErr {
let pipe = Pipe()
let file = pipe.fileHandleForReading
task.standardOutput = pipe
task.standardError = pipe
file.readToEndOfFileInBackground(block: { (data: NSData) in
stdout = NSString(data: data, encoding: String.Encoding.utf8.rawValue) as String
})
file.readToEndOfFileInBackground(block: { (data: NSData) in
stderr = NSString(data: data, encoding: String.Encoding.utf8.rawValue) as String
})
}
task.waitUntilExit()
return (stdout, stderr)
}
// Function to execute binary with arguments.
// Returns tuple where first element is stdout and second is stderr.
func execute(binary: String, arguments: [String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var stdout = ""
var stderr = ""
let outErr = [
"stdout",
"stderr"
]
for e in outErr {
let pipe = Pipe()
let file = pipe.fileHandleForReading
task.standardOutput = pipe
task.standardError = pipe
file.readToEndOfFileInBackground(block: { (data: NSData) in
stdout = NSString(data: data, encoding: String.Encoding.utf8.rawValue) as String
})
file.readToEndOfFileInBackground(block: { (data: NSData) in
stderr = NSString(data: data, encoding: String.Encoding.utf8.rawValue) as String
})
}
task.waitUntilExit()
return (stdout, stderr)
}
```
### 2.3. 执行命令
```swift
// Function to execute binary with arguments.
// Returns tuple where first element is stdout and second is stderr.
func execute(binary: String, arguments: [String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var stdout = ""
var stderr = ""
let outErr = [
"stdout",
"stderr"
]
for efile.readToEndOfFileInBackground(block: { (data: NSData) in // value of type 'FileHandle' has no member 'readToEndOfFileInBackground'stdout = NSString(data: data, encoding: String.Encoding.utf8.rawValue) as String // 'NSString?' is not convertible to 'String'stdout = NSString(data: data, encoding: String.Encoding.utf8.rawValue) as String // 'NSData' is not implicitly convertible to 'Data'; did you mean to use 'as' to explicitly convert?file.readToEndOfFileInBackground(block: { (data: NSData) in // value of type 'FileHandle' has no member 'readToEndOfFileInBackground'stderr = NSString(data: data, encoding: String.Encoding.utf8.rawValue) as String // 'NSString?' is not convertible to 'String'stderr = NSString(data: data, encoding: String.Encoding.utf8.rawValue) as String // 'NSData' is not implicitly convertible to 'Data'; did you mean to use 'as' to explicitly convert?func execute(binary: String, arguments: [String]) -> (String, String) {
let task = NSTask()
task.launchPath = binary
task.arguments = arguments
let pipe = NSPipe()
task.standardOutput = pipe.fileHandleForReading
task.standardError = pipe.fileHandleForReading
let result = task.launch()
if result != 0 {
fatalError("Failed to launch task: \(result)")
}
let stdout = pipe.fileHandleForReading.readDataToEndOfFile()
let stderr = pipe.fileHandleForReading.readDataToEndOfFile()
return (String(data: stdout, encoding: String.Encoding.utf8), String(data: stderr, encoding: String.Encoding.utf8))
}
func execute(binary: String, arguments: [String], environment: [String: String]) -> (String, String) {
let task = NSTask()
task.launchPath = binary
task.arguments = arguments
let pipe = NSPipe()
task.standardOutput = pipe.fileHandleForReading
task.standardError = pipe.fileHandleForReading
let result = task.launch(launchFlags: .LaunchAsync, environment: environment)
if result != 0 {
fatalError("Failed to launch task: \(result)")
}
let stdout = pipe.fileHandleForReading.readDataToEndOfFile()
let stderr = pipe.fileHandleForReading.readDataToEndOfFile()
return (String(data: stdout, encoding: String.Encoding.utf8), String(data: stderr, encoding: String.Encoding.utf8))
}
func execute(binary: String, arguments: [String], environment: [String: String], workingDirectory: String) -> (String, String) {
let task = NSTask()
task.launchPath = binary
task.arguments = arguments
let pipe = NSPipe()
task.standardOutput = pipe.fileHandleForReading
task.standardError = pipe.fileHandleForReading
let result = task.launch(launchFlags: .LaunchAsync, environment: environment, workingDirectory: workingDirectory)
if result != 0 {
fatalError("Failed to launch task: \(result)")
}
let stdout = pipe.fileHandleForReading.readDataToEndOfFile()
let stderr = pipe.fileHandleForReading.readDataToEndOfFile()
return (String(data: stdout, encoding: String.Encoding.utf8), String(data: stderr, encoding: String.Encoding.utf8))
}```swift
// Function to execute binary with arguments.
// Returns tuple where first element is stdout and second is stderr.
func execute(binary: String, arguments: [String]) -> (String, String) {
let task = NSTask()
task.launchPath = binary
task.arguments = arguments
let pipe = NSPipe()
task.standardOutput = pipe.fileHandleForReading
task.standardError = pipe.fileHandleForReading
let result = task.launch()
if result != 0 {
fatalError("Failed to launch task: \(result)")
}
let stdout = pipe.fileHandleForReading.readDataToEndOfFile()
let stderr = pipe.fileHandleForReading.readDataToEndOfFile()
return (String(data: stdout, encoding: String.Encoding.utf8), String(data: stderr, encoding: String.Encoding.utf8))
}
// Function to execute binary with arguments.
// Returns tuple where first element is stdout and second is stderr.
func execute(binary: String, arguments: [String], environment: [String: String]) -> (String, String) {
let task = NSTask()
task.launchPath = binary
task.arguments = arguments
let pipe = NSPipe()
task.standardOutput = pipe.fileHandleForReading
task.standardError = pipe.fileHandleForReading
let result = task.launch(launchFlags: .LaunchAsync, environment: environment)
if result != 0 {
fatalError("Failed to launch task: \(result)")
}
let stdout = pipe.fileHandleForReading.readDataToEndOfFile()
let stderr = pipe.fileHandleForReading.readDataToEndOfFile()
return (String(data: stdout, encoding: String.Encoding.utf8), String(data: stderr, encoding: String.Encoding.utf8))
}
// Function to execute binary with arguments.
// Returns tuple where first element is stdout and second is stderr.
func execute(binary: String, arguments: [String], environment: [String: String], workingDirectory: String) -> (String, String) {
let task = NSTask()
task.launchPath = binary
task.arguments = arguments
let pipe = NSPipe()
task.standardOutput = pipe.fileHandleForReading
task.standardError = pipe.fileHandleForReading
let result = task.launch(launchFlags: .LaunchAsync, environment: environment, workingDirectory: workingDirectory)
if result != 0 {
fatalError("Failed to launch task: \(result)")
}
let stdout = pipe.fileHandleForReading.readDataToEndOfFile()
let stderr = pipe.fileHandleForReading.readDataToEndOfFile()
return (String(data: stdout, encoding: String.Encoding.utf8), String(data: stderr, encoding: String.Encoding.utf8))
}
```
### 参考
- [Swift で NSTask を使ってコマンドを実行する](https://qiita.com/kou_t/items/23655288-swift-nstask-kou-t)
- [Swift で NSTask を使ってコマンドを実行する（2）](https://qiita.com/kou_t/items/23655288-swift-nstask-kou-t)
- [Swift で NSTask を使ってコマンドを実行する（3）](https://qiita.com/kou_t/items/23655288-swift-nstask-kou-t)
- [Swift で NSTask を使ってコマンドを実行する（4）](https://qiita.com/kou_t/items/23655288-swift-nstask-kou-t)
- [Swift で NSTask を使ってコマンドを実行する（5）](https://qiita.com/klet task = NSTask() // 'NSTask' has been renamed to 'Process'let pipe = NSPipe() // 'NSPipe' has been renamed to 'Pipe'let result = task.launch() // constant 'result' inferred to have type 'Void', which may be unexpectedif result != 0 { // binary operator '!=' cannot be applied to operands of type 'Void' and 'Int'return (String(data: stdout, encoding: String.Encoding.utf8), String(data: stderr, encoding: String.Encoding.utf8)) // cannot convert return expression of type '(String?, String?)' to return type '(String, String)'let task = NSTask() // 'NSTask' has been renamed to 'Process'let pipe = NSPipe() // 'NSPipe' has been renamed to 'Pipe'let result = task.launch(launchFlags: .LaunchAsync, environment: environment) // cannot infer contextual base in reference to member 'LaunchAsync'let result = task.launch(launchFlags: .LaunchAsync, environment: environment) // argument passed to call that takes no argumentsreturn (String(data: stdout, encoding: String.Encoding.utf8), String(data: stderr, encoding: String.Encoding.utf8)) // cannot convert return expression of type '(String?, String?)' to return type '(String, String)'let task = NSTask() // 'NSTask' has been renamed to 'Process'let pipe = NSPipe() // 'NSPipe' has been renamed to 'Pipe'let result = task.launch(launchFlags: .LaunchAsync, environment: environment, workingDirectory: workingDirectory) // cannot infer contextual base in reference to member 'LaunchAsync'let result = task.launch(launchFlags: .LaunchAsync, environment: environment, workingDirectory: workingDirectory) // argument passed to call that takes no argumentsreturn (String(data: stdout, encoding: String.Encoding.utf8), String(data: stderr, encoding: String.Encoding.utf8)) // cannot convert return expression of type '(String?, String?)' to return type '(String, String)'func execute(binary: String, arguments: [String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var out = ""
var err = ""
let outData = NSMutableData()
let errData = NSMutableData()
let outPipe = NSPipe()
let errPipe = NSPipe()
task.standardOutput = outPipe
task.standardError = errPipe
task.waitUntilExit()
outPipe.fileHandleForReading.readDataToEndOfFileInBackgroundAndNotify() { [weak self] (data) -> Void in
outData.appendData(data)
}
errPipe.fileHandleForReading.readDataToEndOfFileInBackgroundAndNotify() { [weak self] (data) -> Void in
errData.appendData(data)
}
out = String(data: outData, encoding: String.Encoding.utf8.rawValue)
err = String(data: errData, encoding: String.Encoding.utf8.rawValue)
return (out, err)
}```swift
// Function to execute binary with arguments.
// Returns tuple where first element is stdout and second is stderr.
func execute(binary: String, arguments: [String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var out = ""
var err = ""
let outData = NSMutableData()
let errData = NSMutableData()
let outPipe = NSPipe()
let errPipe = NSPipe()
task.standardOutput = outPipe
task.standardError = errPipe
task.waitUntilExit()
outPipe.fileHandleForReading.readDataToEndOfFileInBackgroundAndNotify() { [weak self] (data) -> Void in
outData.appendData(data)
}
errPipe.fileHandleForReading.readDataToEndOfFileInBackgroundAndNotify() { [weak self] (data) -> Void in
errData.appendData(data)
}
out = String(data: outData, encoding: String.Encoding.utf8.rawValue)
err = String(data: errData, encoding: String.Encoding.utf8.rawValue)
return (out, err)
}
```
### 2. 执行命令
```swift
// Function to execute binary with arguments.
// Returns tuple where first element is stdout and second is stderr.
func execute(binary: String, arguments: [String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var out = ""
var err = ""
let outData = NSMutableData()
let errData = NSMutableData()
let outPipe = NSPipe()
let errPipe = NSPipe()
task.standardOutput = outPipe
task.standardError = errPipe
task.waitUntilExit()
outPipe.fileHandleForReading.readDataToEndOfFileInBackgroundAndNotify() { [weak self] (data) -> Void in
outData.appendData(data)
}
errPipe.fileHandleForReading.readDataToEndOfFileInBackgroundAndNotify() { [weak self] (data) -> Void in
errData.appendData(data)
}
out = String(data: outData, encoding: String.Encoding.utf8.rawValue)
err = String(data: errData, encoding: String.Encoding.utf8.rawValue)
return (out, err)
}
```
### 3. 执行命令
```swift
// Function to execute binary with arguments.
// Returns tuple where first element is stdout and second is stderr.
func execute(binary: String, arguments: [String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var out = ""
var err = ""
let outData = NSMutableData()
let errData = NSMutableData()
let outPipe = NSPipe()
let errPipe = NSPipe()
task.standardOutput = outPipe
task.standardError = errPipe
task.waitUntilExit()
outPipe.fileHandleForReading.readDataToEndOfFileInBackgroundAndNotify() { [weak self] (data) -> Void in
outData.appendData(data)
}
errPipe.fileHandleForReading.readDataToEndOfFileInBackgroundAndNotify() { [weak self] (data) -> Void in
errData.appendData(data)
}
out = String(data: outData, encoding: String.Encoding.utf8.rawValue)
err = String(data: errData, encoding: String.Encoding.utf8.rawValue)
return (out, err)
}
```
### 4. 执行let outPipe = NSPipe() // 'NSPipe' has been renamed to 'Pipe'let errPipe = NSPipe() // 'NSPipe' has been renamed to 'Pipe'outPipe.fileHandleForReading.readDataToEndOfFileInBackgroundAndNotify() { [weak self] (data) -> Void in // cannot find 'self' in scope; did you mean to use it in a type or extension context?outPipe.fileHandleForReading.readDataToEndOfFileInBackgroundAndNotify() { [weak self] (data) -> Void in // value of type 'FileHandle' has no member 'readDataToEndOfFileInBackgroundAndNotify'errPipe.fileHandleForReading.readDataToEndOfFileInBackgroundAndNotify() { [weak self] (data) -> Void in // cannot find 'self' in scope; did you mean to use it in a type or extension context?errPipe.fileHandleForReading.readDataToEndOfFileInBackgroundAndNotify() { [weak self] (data) -> Void in // value of type 'FileHandle' has no member 'readDataToEndOfFileInBackgroundAndNotify'out = String(data: outData, encoding: String.Encoding.utf8.rawValue) // 'NSMutableData' is not implicitly convertible to 'Data'; did you mean to use 'as' to explicitly convert?out = String(data: outData, encoding: String.Encoding.utf8.rawValue) // cannot convert value of type 'UInt' to expected argument type 'String.Encoding'out = String(data: outData, encoding: String.Encoding.utf8.rawValue) // value of optional type 'String?' must be unwrapped to a value of type 'String'err = String(data: errData, encoding: String.Encoding.utf8.rawValue) // value of optional type 'String?' must be unwrapped to a value of type 'String'err = String(data: errData, encoding: String.Encoding.utf8.rawValue) // 'NSMutableData' is not implicitly convertible to 'Data'; did you mean to use 'as' to explicitly convert?err = String(data: errData, encoding: String.Encoding.utf8.rawValue) // cannot convert value of type 'UInt' to expected argument type 'String.Encoding'func execute(binary: String, arguments: [String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var stdout = ""
var stderr = ""
let outErr = [
"stdout",
"stderr"
]
for output in outErr {
let pipe = Pipe()
let file = pipe.fileHandleForReading
file.readDataToEndOfFile()
if output == "stdout" {
stdout = file.readDataToEndOfFile()
} else {
stderr = file.readDataToEndOfFile()
}
}
return (stdout, stderr)
}
func execute(binary: String, arguments: [String], environment: [String: String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var stdout = ""
var stderr = ""
let outErr = [
"stdout",
"stderr"
]
for output in outErr {
let pipe = Pipe()
let file = pipe.fileHandleForReading
file.readDataToEndOfFile()
if output == "stdout" {
stdout = file.readDataToEndOfFile()
} else {
stderr = file.readDataToEndOfFile()
}
}
return (stdout, stderr)
}```swift
// Function to execute binary with arguments.
// Returns tuple where first element is stdout and second is stderr.
func execute(binary: String, arguments: [String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var stdout = ""
var stderr = ""
let outErr = [
"stdout",
"stderr"
]
for output in outErr {
let pipe = Pipe()
let file = pipe.fileHandleForReading
file.readDataToEndOfFile()
if output == "stdout" {
stdout = file.readDataToEndOfFile()
} else {
stderr = file.readDataToEndOfFile()
}
}
return (stdout, stderr)
}
// Function to execute binary with arguments.
// Returns tuple where first element is stdout and second is stderr.
func execute(binary: String, arguments: [String], environment: [String: String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var stdout = ""
var stderr = ""
let outErr = [
"stdout",
"stderr"
]
for output in outErr {
let pipe = Pipe()
let file = pipe.fileHandleForReading
file.readDataToEndOfFile()
if output == "stdout" {
stdout = file.readDataToEndOfFile()
} else {
stderr = file.readDataToEndOfFile()
}
}
return (stdout, stderr)
}
```
### Swift 4
```swift
// Function to execute binary with arguments.
// Returns tuple where first element is stdout and second is stderr.
func execute(binary: String, arguments: [String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var stdout = ""
var stderr = ""
let outErr = [
"stdout",
"stderr"
]
for output in outErr {
let pipe = Pipe()
let file = pipe.fileHandleForReading
file.readDataToEndOfFile()
if output == "stdout" {
stdout = file.readDataToEndOfFile()
} else {
stderr = file.readDataToEndOfFile()
}
}
return (stdout, stderr)
}
// Function to execute binary with arguments.
// Returns tuple where first element is stdout and second is stderr.
func execute(binary: String, arguments: [String], environment: [String: String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var stdout = ""
var stderr = ""
let outErr = [
"stdout",
"stderr"
]
for output in outErr {
let pipe = Pipe()
let file = pipe.fileHandleForReading
file.readDataToEndOfFile()
if output == "stdout" {
stdout = file.readDataToEndOfFile()
} else {
stderr = file.readDataToEndOfFile()
}
}
return (stdout, stderr)
}
```
### Swift 5
```swift
// Function to execute binary with arguments.
// Returns tuple where first element is stdout and second is stderr.
func execute(binary: String, arguments: [String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var stdout = ""
var stderr = ""
let outErr = [
"stdout",
"stderr"
]
for output in outstdout = file.readDataToEndOfFile() // cannot assign value of type 'Data' to type 'String'stderr = file.readDataToEndOfFile() // cannot assign value of type 'Data' to type 'String'stdout = file.readDataToEndOfFile() // cannot assign value of type 'Data' to type 'String'stderr = file.readDataToEndOfFile() // cannot assign value of type 'Data' to type 'String'func execute(binary: String, arguments: [String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var out = ""
var err = ""
var outLine = ""
var errLine = ""
while let outLine = task.standardOutput.readLine() {
out += outLine
}
while let errLine = task.standardError.readLine() {
err += errLine
}
return (out, err)
}
func execute(binary: String, arguments: [String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var out = ""
var err = ""
while let outLine = task.standardOutput.readLine() {
out += outLine
}
while let errLine = task.standardError.readLine() {
err += errLine
}
return (out, err)
}```swift
// Function to execute binary with arguments.
// Returns tuple where first element is stdout and second is stderr.
func execute(binary: String, arguments: [String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var out = ""
var err = ""
var outLine = ""
var errLine = ""
while let outLine = task.standardOutput.readLine() {
out += outLine
}
while let errLine = task.standardError.readLine() {
err += errLine
}
return (out, err)
}
// Function to execute binary with arguments.
// Returns tuple where first element is stdout and second is stderr.
func execute(binary: String, arguments: [String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var out = ""
var err = ""
while let outLine = task.standardOutput.readLine() {
out += outLine
}
while let errLine = task.standardError.readLine() {
err += errLine
}
return (out, err)
}
// Function to execute binary with arguments.
// Returns tuple where first element is stdout and second is stderr.
func execute(binary: String, arguments: [String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var out = ""
var err = ""
while let outLine = task.standardOutput.readLine() {
out += outLine
}
while let errLine = task.standardError.readLine() {
err += errLine
}
return (out, err)
}
// Function to execute binary with arguments.
// Returns tuple where first element is stdout and second is stderr.
func execute(binary: String, arguments: [String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var out = ""
var err = ""
while let outLine = task.standardOutput.readLine() {
out += outLine
}
while let errLine = task.standardError.readLine() {
err += errLine
}
return (out, err)
}
// Function to execute binary with arguments.
// Returns tuple where first element is stdout and second is stderr.
func execute(binary: String, arguments: [String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var out = ""
var err = ""
while let outLine = task.standardOutput.readLine() {
out += outLine
}
while let errLine = task.standardError.readLine() {
err += errLine
}
return (out, err)
}
// Function to execute binary with arguments.
// Returns tuple where first element is stdout and second is stderr.
func execute(binary: String, arguments: [String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var out = ""
var err = ""
while let outLine = task.standardOutput.readLine() {
out += outLine
}
while let errLine = task.standardError.readLine() {
err += errLine
}
return (out, err)
}
// Function to execute binary with arguments.
// Returns tuple where first element is stdout and second is stderr.
func execute(binary: String, arguments: [String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var out = ""
var err = ""
while let outLine = task.standardOutput.readLine() {
out += outLine
}
while let errLine = task.standardError.readLine() {
err += errLine
}
return (out, err)
}while let outLine = task.standardOutput.readLine() { // value of type 'Any?' has no member 'readLine'while let errLine = task.standardError.readLine() { // value of type 'Any?' has no member 'readLine'func execute(binary: String, arguments: [String]) -> (String, String) { // invalid redeclaration of 'execute(binary:arguments:)'while let outLine = task.standardOutput.readLine() { // value of type 'Any?' has no member 'readLine'while let errLine = task.standardError.readLine() { // value of type 'Any?' has no member 'readLine'func execute(binary: String, arguments: [String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var output = ""
var error = ""
let outpipe = NSPipe()
task.standardOutput = outpipe
task.standardError = outpipe
let outreader = outpipe.fileHandleForReading
outreader.waitForDataInBackgroundAndNotify()
let outcallback = { [unowned outreader] in
let data = outreader.readDataOfLength(1024)
output += NSString(data: data, encoding: String.Encoding.utf8.rawValue) ?? ""
outreader.waitForDataInBackgroundAndNotify()
}
outreader.notificationCenter.addObserver(self, selector: #selector(outcallback), name: NSPipeDataAvailableNotification, object: outpipe)
outreader.waitForDataInBackgroundAndNotify()
let errpipe = NSPipe()
task.standardOutput = errpipe
task.standardError = errpipe
let errreader = errpipe.fileHandleForReading
errreader.waitForDataInBackgroundAndNotify()
let errcallback = { [unowned errreader] in
let data = errreader.readDataOfLength(1024)
error += NSString(data: data, encoding: String.Encoding.utf8.rawValue) ?? ""
errreader.waitForDataInBackgroundAndNotify()
}
errreader.notificationCenter.addObserver(self, selector: #selector(errcallback), name: NSPipeDataAvailableNotification, object: errpipe)
errreader.waitForDataInBackgroundAndNotify()
task.waitUntilExit()
return (output, error)
}
func execute(binary: String, arguments: [String], input: String) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var output = ""
var error = ""
let outpipe = NSPipe()
task.standardOutput = outpipe
task.standardError = outpipe
let outreader = outpipe.fileHandleForReading
outreader.waitForDataInBackgroundAndNotify()
let outcallback = { [unowned outreader] in
let data = outreader.readDataOfLength(1024)
output += NSString(data: data, encoding: String.Encoding.utf8.rawValue) ?? ""
outreader.waitForDataInBackgroundAndNotify()
}
outreader.notificationCenter.addObserver(self, selector: #selector(outcallback), name: NSPipeDataAvailableNotification, object: outpipe)
outreader.waitForDataInBackgroundAndNotify()
let errpipe = NSPipe()
task.standardOutput = errpipe
task.standardError = errpipe
let errreader = errpipe.fileHandleForReading
errreader.waitForDataInBackgroundAndNotify()
let errcallback = { [unowned errreader] in
let data = errreader.readDataOfLength(1024)
error += NSString(data: data, encoding: String.Encoding.utf8.rawValue) ?? ""
errreader.waitForDataInBackgroundAndNotify()
}
errreader.notificationCenter.addObserver(self, selector: #selector(errcallback), name: NSPipeDataAvailableNotification, object: errpipe)
errreader.waitForDataInBackgroundAndNotify()
task.write(input.data(using: String.Encoding.utf8.rawValue)!)
task.waitUntilExit()
return (output, error)
}```swift
// Function to execute binary with arguments.
// Returns tuple where first element is stdout and second is stderr.
func execute(binary: String, arguments: [String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var output = ""
var error = ""
let outpipe = NSPipe()
task.standardOutput = outpipe
task.standardError = outpipe
let outreader = outpipe.fileHandleForReading
outreader.waitForDataInBackgroundAndNotify()
let outcallback = { [unowned outreader] in
let data = outreader.readDataOfLength(1024)
output += NSString(data: data, encoding: String.Encoding.utf8.rawValue) ?? ""
outreader.waitForDataInBackgroundAndNotify()
}
outreader.notificationCenter.addObserver(self, selector: #selector(outcallback), name: NSPipeDataAvailableNotification, object: outpipe)
outreader.waitForDataInBackgroundAndNotify()
let errpipe = NSPipe()
task.standardOutput = errpipe
task.standardError = errpipe
let errreader = errpipe.fileHandleForReading
errreader.waitForDataInBackgroundAndNotify()
let errcallback = { [unowned errreader] in
let data = errreader.readDataOfLength(1024)
error += NSString(data: data, encoding: String.Encoding.utf8.rawValue) ?? ""
errreader.waitForDataInBackgroundAndNotify()
}
errreader.notificationCenter.addObserver(self, selector: #selector(errcallback), name: NSPipeDataAvailableNotification, object: errpipe)
errreader.waitForDataInBackgroundAndNotify()
task.waitUntilExit()
return (output, error)
}
// Function to execute binary with arguments.
// Returns tuple where first element is stdout and second is stderr.
func execute(binary: String, arguments: [String], input: String) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var output = ""
var error = ""
let outpipe = NSPipe()
task.standardOutput = outpipe
task.standardError = outpipe
let outreader = outpipe.fileHandleForReading
outreader.waitForDataInBackgroundAndNotify()
let outcallback = { [unowned outreader] in
let data = outreader.readDataOfLength(1024)
output += NSString(data: data, encoding: String.Encoding.utf8.rawValue) ?? ""
outreader.waitForDataInBackgroundAndNotify()
}
outreader.notificationCenter.addObserver(self, selector: #selector(outcallback), name: NSPipeDataAvailableNotification, object: outpipe)
outreader.waitForDataInBackgroundAndNotify()
let errpipe = NSPipe()
task.standardOutput = errpipe
task.standardError = errpipe
let errreader = errpipe.fileHandleForReading
errreader.waitForDataInBackgroundAndNotify()
let errcallback = { [unowned errreader] in
let data = errreader.readDataOfLength(1024)
error += NSString(data: data, encoding: String.Encoding.utf8.rawValue) ?? ""
errreader.waitForDataInBackgroundAndNotify()
}
errreader.notificationCenter.addObserver(self, selector: #selector(errcallback), name: NSPipeDataAvailableNotification, object: errpipe)
errreader.waitForDataInBackgroundAndNotify()
task.write(input.data(using: String.Encoding.utf8.rawValue)!)
task.waitUntilExit()
return (output, error)
}
```
### 参考
- [Swift での Process の使い方](https://qiita.com/let outpipe = NSPipe() // 'NSPipe' has been renamed to 'Pipe'output += NSString(data: data, encoding: String.Encoding.utf8.rawValue) ?? "" // 'NSString' is not implicitly convertible to 'String'; did you mean to use 'as' to explicitly convert?outreader.notificationCenter.addObserver(self, selector: #selector(outcallback), name: NSPipeDataAvailableNotification, object: outpipe) // cannot find 'self' in scope; did you mean to use it in a type or extension context?outreader.notificationCenter.addObserver(self, selector: #selector(outcallback), name: NSPipeDataAvailableNotification, object: outpipe) // cannot find 'NSPipeDataAvailableNotification' in scopeoutreader.notificationCenter.addObserver(self, selector: #selector(outcallback), name: NSPipeDataAvailableNotification, object: outpipe) // value of type 'FileHandle' has no member 'notificationCenter'let errpipe = NSPipe() // 'NSPipe' has been renamed to 'Pipe'error += NSString(data: data, encoding: String.Encoding.utf8.rawValue) ?? "" // 'NSString' is not implicitly convertible to 'String'; did you mean to use 'as' to explicitly convert?errreader.notificationCenter.addObserver(self, selector: #selector(errcallback), name: NSPipeDataAvailableNotification, object: errpipe) // cannot find 'self' in scope; did you mean to use it in a type or extension context?errreader.notificationCenter.addObserver(self, selector: #selector(errcallback), name: NSPipeDataAvailableNotification, object: errpipe) // cannot find 'NSPipeDataAvailableNotification' in scopeerrreader.notificationCenter.addObserver(self, selector: #selector(errcallback), name: NSPipeDataAvailableNotification, object: errpipe) // value of type 'FileHandle' has no member 'notificationCenter'let outpipe = NSPipe() // 'NSPipe' has been renamed to 'Pipe'output += NSString(data: data, encoding: String.Encoding.utf8.rawValue) ?? "" // 'NSString' is not implicitly convertible to 'String'; did you mean to use 'as' to explicitly convert?outreader.notificationCenter.addObserver(self, selector: #selector(outcallback), name: NSPipeDataAvailableNotification, object: outpipe) // cannot find 'NSPipeDataAvailableNotification' in scopeoutreader.notificationCenter.addObserver(self, selector: #selector(outcallback), name: NSPipeDataAvailableNotification, object: outpipe) // value of type 'FileHandle' has no member 'notificationCenter'outreader.notificationCenter.addObserver(self, selector: #selector(outcallback), name: NSPipeDataAvailableNotification, object: outpipe) // cannot find 'self' in scope; did you mean to use it in a type or extension context?let errpipe = NSPipe() // 'NSPipe' has been renamed to 'Pipe'error += NSString(data: data, encoding: String.Encoding.utf8.rawValue) ?? "" // 'NSString' is not implicitly convertible to 'String'; did you mean to use 'as' to explicitly convert?errreader.notificationCenter.addObserver(self, selector: #selector(errcallback), name: NSPipeDataAvailableNotification, object: errpipe) // cannot find 'NSPipeDataAvailableNotification' in scopeerrreader.notificationCenter.addObserver(self, selector: #selector(errcallback), name: NSPipeDataAvailableNotification, object: errpipe) // cannot find 'self' in scope; did you mean to use it in a type or extension context?errreader.notificationCenter.addObserver(self, selector: #selector(errcallback), name: NSPipeDataAvailableNotification, object: errpipe) // value of type 'FileHandle' has no member 'notificationCenter'task.write(input.data(using: String.Encoding.utf8.rawValue)!) // value of type 'Process' has no member 'write'task.write(input.data(using: String.Encoding.utf8.rawValue)!) // cannot convert value of type 'UInt' to expected argument type 'String.Encoding'func execute(binary: String, arguments: [String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var out = ""
var err = ""
var outLine = ""
var errLine = ""
while let outLine = task.standardOutput.readLine() {
out += outLine
}
while let errLine = task.standardError.readLine() {
err += errLine
}
return (out, err)
}
func execute(binary: String, arguments: [String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var out = ""
var err = ""
while let outLine = task.standardOutput.readLine() {
out += outLine
}
while let errLine = task.standardError.readLine() {
err += errLine
}
return (out, err)
}```swift
// Function to execute binary with arguments.
// Returns tuple where first element is stdout and second is stderr.
func execute(binary: String, arguments: [String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var out = ""
var err = ""
var outLine = ""
var errLine = ""
while let outLine = task.standardOutput.readLine() {
out += outLine
}
while let errLine = task.standardError.readLine() {
err += errLine
}
return (out, err)
}
```
### 解法二
```swift
// Function to execute binary with arguments.
// Returns tuple where first element is stdout and second is stderr.
func execute(binary: String, arguments: [String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var out = ""
var err = ""
while let outLine = task.standardOutput.readLine() {
out += outLine
}
while let errLine = task.standardError.readLine() {
err += errLine
}
return (out, err)
}
```while let outLine = task.standardOutput.readLine() { // value of type 'Any?' has no member 'readLine'while let errLine = task.standardError.readLine() { // value of type 'Any?' has no member 'readLine'func execute(binary: String, arguments: [String]) -> (String, String) { // invalid redeclaration of 'execute(binary:arguments:)'while let outLine = task.standardOutput.readLine() { // value of type 'Any?' has no member 'readLine'while let errLine = task.standardError.readLine() { // value of type 'Any?' has no member 'readLine'func execute(binary: String, arguments: [String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var output = ""
var error = ""
let outpipe = NSPipe()
task.standardOutput = outpipe
task.standardError = outpipe
let outreader = outpipe.fileHandleForReading
outreader.waitForDataInBackgroundAndNotify()
let outcallback = { [unowned outreader] in
let data = outreader.readDataOfLength(1024)
if data.length > 0 {
output += NSString(data: data, encoding: NSUTF8StringEncoding)
}
}
outreader.addPerformAction(callback: outcallback, onQueue: NSOperationQueue.mainQueue())
let errpipe = NSPipe()
task.standardOutput = errpipe
task.standardError = errpipe
let errreader = errpipe.fileHandleForReading
errreader.waitForDataInBackgroundAndNotify()
let errcallback = { [unowned errreader] in
let data = errreader.readDataOfLength(1024)
if data.length > 0 {
error += NSString(data: data, encoding: NSUTF8StringEncoding)
}
}
errreader.addPerformAction(callback: errcallback, onQueue: NSOperationQueue.mainQueue())
task.waitUntilExit()
return (output, error)
}```swift
// Function to execute binary with arguments.
// Returns tuple where first element is stdout and second is stderr.
func execute(binary: String, arguments: [String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var output = ""
var error = ""
let outpipe = NSPipe()
task.standardOutput = outpipe
task.standardError = outpipe
let outreader = outpipe.fileHandleForReading
outreader.waitForDataInBackgroundAndNotify()
let outcallback = { [unowned outreader] in
let data = outreader.readDataOfLength(1024)
if data.length > 0 {
output += NSString(data: data, encoding: NSUTF8StringEncoding)
}
}
outreader.addPerformAction(callback: outcallback, onQueue: NSOperationQueue.mainQueue())
let errpipe = NSPipe()
task.standardOutput = errpipe
task.standardError = errpipe
let errreader = errpipe.fileHandleForReading
errreader.waitForDataInBackgroundAndNotify()
let errcallback = { [unowned errreader] in
let data = errreader.readDataOfLength(1024)
if data.length > 0 {
error += NSString(data: data, encoding: NSUTF8StringEncoding)
}
}
errreader.addPerformAction(callback: errcallback, onQueue: NSOperationQueue.mainQueue())
task.waitUntilExit()
return (output, error)
}
```
### 2. 执行命令
```swift
// Function to execute binary with arguments.
// Returns tuple where first element is stdout and second is stderr.
func execute(binary: String, arguments: [String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var output = ""
var error = ""
let outpipe = NSPipe()
task.standardOutput = outpipe
task.standardError = outpipe
let outreader = outpipe.fileHandleForReading
outreader.waitForDataInBackgroundAndNotify()
let outcallback = { [unowned outreader] in
let data = outreader.readDataOfLength(1024)
if data.length > 0 {
output += NSString(data: data, encoding: NSUTF8StringEncoding)
}
}
outreader.addPerformAction(callback: outcallback, onQueue: NSOperationQueue.mainQueue())
let errpipe = NSPipe()
task.standardOutput = errpipe
task.standardError = errpipe
let errreader = errpipe.fileHandleForReading
errreader.waitForDataInBackgroundAndNotify()
let errcallback = { [unowned errreader] in
let data = errreader.readDataOfLength(1024)
if data.length > 0 {
error += NSString(data: data, encoding: NSUTF8StringEncoding)
}
}
errreader.addPerformAction(callback: errcallback, onQueue: NSOperationQueue.mainQueue())
task.waitUntilExit()
return (output, error)
}
// Example usage
let (output, error) = execute(binary: "/bin/ls", arguments: ["-la"])
print(output)
print(error)
```
### 3. 执行命令并获取返回值
```swift
// Function to execute binary with arguments.
// Returns tuple where first element is stdout and second is stderr.
func execute(binary: String, arguments: [String]) -> (String, String, Int) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var output = ""
var error = ""
let outpipe = NSPipe()
task.standardOutput = outpipe
task.standardError = outpipe
let outreader = outpipe.fileHandlelet outpipe = NSPipe() // 'NSPipe' has been renamed to 'Pipe'if data.length > 0 { // value of type 'Data' has no member 'length'outreader.addPerformAction(callback: outcallback, onQueue: NSOperationQueue.mainQueue()) // cannot call value of non-function type 'OperationQueue'outreader.addPerformAction(callback: outcallback, onQueue: NSOperationQueue.mainQueue()) // value of type 'FileHandle' has no member 'addPerformAction'let errpipe = NSPipe() // 'NSPipe' has been renamed to 'Pipe'if data.length > 0 { // value of type 'Data' has no member 'length'errreader.addPerformAction(callback: errcallback, onQueue: NSOperationQueue.mainQueue()) // cannot call value of non-function type 'OperationQueue'errreader.addPerformAction(callback: errcallback, onQueue: NSOperationQueue.mainQueue()) // value of type 'FileHandle' has no member 'addPerformAction'func execute(binary: String, arguments: [String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var out = ""
var err = ""
let outData = NSMutableData()
let errData = NSMutableData()
let outPipe = NSPipe()
let errPipe = NSPipe()
task.standardOutput = outPipe
task.standardError = errPipe
task.waitUntilExit()
outPipe.fileHandleForReading.readDataToEndOfFileInBackgroundAndNotify() { (data) -> Void in
outData.appendData(data)
}
errPipe.fileHandleForReading.readDataToEndOfFileInBackgroundAndNotify() { (data) -> Void in
errData.appendData(data)
}
out = NSString(data: outData, encoding: NSUTF8StringEncoding) as String
err = NSString(data: errData, encoding: NSUTF8StringEncoding) as String
return (out, err)
}```swift
// Function to execute binary with arguments.
// Returns tuple where first element is stdout and second is stderr.
func execute(binary: String, arguments: [String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var out = ""
var err = ""
let outData = NSMutableData()
let errData = NSMutableData()
let outPipe = NSPipe()
let errPipe = NSPipe()
task.standardOutput = outPipe
task.standardError = errPipe
task.waitUntilExit()
outPipe.fileHandleForReading.readDataToEndOfFileInBackgroundAndNotify() { (data) -> Void in
outData.appendData(data)
}
errPipe.fileHandleForReading.readDataToEndOfFileInBackgroundAndNotify() { (data) -> Void in
errData.appendData(data)
}
out = NSString(data: outData, encoding: NSUTF8StringEncoding) as String
err = NSString(data: errData, encoding: NSUTF8StringEncoding) as String
return (out, err)
}
```
### 2. 执行命令
```swift
// Function to execute binary with arguments.
// Returns tuple where first element is stdout and second is stderr.
func execute(binary: String, arguments: [String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var out = ""
var err = ""
let outData = NSMutableData()
let errData = NSMutableData()
let outPipe = NSPipe()
let errPipe = NSPipe()
task.standardOutput = outPipe
task.standardError = errPipe
task.waitUntilExit()
outPipe.fileHandleForReading.readDataToEndOfFileInBackgroundAndNotify() { (data) -> Void in
outData.appendData(data)
}
errPipe.fileHandleForReading.readDataToEndOfFileInBackgroundAndNotify() { (data) -> Void in
errData.appendData(data)
}
out = NSString(data: outData, encoding: NSUTF8StringEncoding) as String
err = NSString(data: errData, encoding: NSUTF8StringEncoding) as String
return (out, err)
}
```
### 3. 执行命令
```swift
// Function to execute binary with arguments.
// Returns tuple where first element is stdout and second is stderr.
func execute(binary: String, arguments: [String]) -> (String, String) {
let task = Process()
task.launchPath = binary
task.arguments = arguments
task.launch()
var out = ""
var err = ""
let outData = NSMutableData()
let errData = NSMutableData()
let outPipe = NSPipe()
let errPipe = NSPipe()
task.standardOutput = outPipe
task.standardError = errPipe
task.waitUntilExit()
outPipe.fileHandleForReading.readDataToEndOfFileInBackgroundAndNotify() { (data) -> Void in
outData.appendData(data)
}
errPipe.fileHandleForReading.readDataToEndOfFileInBackgroundAndNotify() { (data) -> Void in
errData.appendData(data)
}
out = NSString(data: outData, encoding: NSUTF8StringEncoding) as String
err = NSString(data: errData, encoding: NSUTF8StringEncoding) as String
return (out, err)
}
```
### 4. 执行命令
```swift
// Function to execute binary with arguments.
// Returns tuple where first element is stdout and second is stderr.
func executelet outPipe = NSPipe() // 'NSPipe' has been renamed to 'Pipe'let errPipe = NSPipe() // 'NSPipe' has been renamed to 'Pipe'outPipe.fileHandleForReading.readDataToEndOfFileInBackgroundAndNotify() { (data) -> Void in // value of type 'FileHandle' has no member 'readDataToEndOfFileInBackgroundAndNotify'errPipe.fileHandleForReading.readDataToEndOfFileInBackgroundAndNotify() { (data) -> Void in // value of type 'FileHandle' has no member 'readDataToEndOfFileInBackgroundAndNotify'out = NSString(data: outData, encoding: NSUTF8StringEncoding) as String // 'NSString?' is not convertible to 'String'out = NSString(data: outData, encoding: NSUTF8StringEncoding) as String // 'NSMutableData' is not implicitly convertible to 'Data'; did you mean to use 'as' to explicitly convert?err = NSString(data: errData, encoding: NSUTF8StringEncoding) as String // 'NSMutableData' is not implicitly convertible to 'Data'; did you mean to use 'as' to explicitly convert?err = NSString(data: errData, encoding: NSUTF8StringEncoding) as String // 'NSString?' is not convertible to 'String'func memoize<T: Hashable, U>(_ function: @escaping (T) -> U) -> (T) -> U {
var cache = [T: U]()
return { x in
cache[x, default: function(x) ]
}
}
func fib(_ n: Int) -> Int {
if n < 2 {
return n
}
var dp = [Int](repeating: 0, count: n + 1)
dp[1] = 1
for i in 2...n {
dp[i] = dp[i - 1] + dp[i - 2]
}
return dp[n]
}
func fib(_ n: Int) -> Int {
let base = [
[1, 1],
[1, 0]
]
let res = pow(base, n)
return res[0][1]
}
func pow(_ base: [[Int]], _ n: Int) -> [[Int]] {
var res = base
var tmp = base
var times = n
while times > 1 {
if times % 2 == 1 {
res = multiply(res, tmp)
}
tmp = multiply(tmp, tmp)
times /= 2
}
return res
}
func multiply(_ a: [[Int]], _ b: [[Int]]) -> [[Int]] {
var res = [[Int]](repeating: [Int](repeating: 0, count: b[0].count), count: a.count)
for i in 0..<a.count {
for j in 0..<b[0].count {
for k in 0..<a[0].count {
res[i][j] += a[i][k] * b[k][j]
}
}
}
return res
}
func fib(_ n: Int) -> Int {
if n < 2 {
return n
}
return fib(n - 1) + fib(n - 2)
}
func fib(_ n: Int) -> Int {
fib_helper(n, 0, 1)
}
@inline(__always)
func fib_helper(_ n: Int, _ a: Int, _ b: Int) -> Int {
if n == 0 {
return a
}
return fib_helper(n - 1, b, a + b)
}```swift
// Memoization function that caches the results of expensive computations.
func memoize<T: Hashable, U>(_ function: @escaping (T) -> U) -> (T) -> U {
var cache = [T: U]()
return { x in
cache[x, default: function(x) ]
}
}
```
### 解法二：动态规划
```swift
func fib(_ n: Int) -> Int {
if n < 2 {
return n
}
var dp = [Int](repeating: 0, count: n + 1)
dp[1] = 1
for i in 2...n {
dp[i] = dp[i - 1] + dp[i - 2]
}
return dp[n]
}
```
### 解法三：矩阵快速幂
```swift
func fib(_ n: Int) -> Int {
let base = [
[1, 1],
[1, 0]
]
let res = pow(base, n)
return res[0][1]
}
func pow(_ base: [[Int]], _ n: Int) -> [[Int]] {
var res = base
var tmp = base
var times = n
while times > 1 {
if times % 2 == 1 {
res = multiply(res, tmp)
}
tmp = multiply(tmp, tmp)
times /= 2
}
return res
}
func multiply(_ a: [[Int]], _ b: [[Int]]) -> [[Int]] {
var res = [[Int]](repeating: [Int](repeating: 0, count: b[0].count), count: a.count)
for i in 0..<a.count {
for j in 0..<b[0].count {
for k in 0..<a[0].count {
res[i][j] += a[i][k] * b[k][j]
}
}
}
return res
}
```
### 解法四：递归
```swift
func fib(_ n: Int) -> Int {
if n < 2 {
return n
}
return fib(n - 1) + fib(n - 2)
}
```
### 解法五：尾递归
```swift
func fib(_ n: Int) -> Int {
fib_helper(n, 0, 1)
}
@inline(__always)
func fib_helper(_ n: Int, _ a: Int, _ b: Int) -> Int {
if n == 0 {
return a
}
return fib_helper(n - 1, b, a + b)
}
```
### 解法六：尾递归优化
```swift
func fib(_ n: Int) -> Int {
fib_helper(n, 0, 1)
}
@inline(__always)
func fib_helper(_ n: Int, _ a: Int, _ b: Int) -> Int {
if n == 0 {
return a
}
return fib_helper(n - 1, b, a + b)
}
@inline(__always)
func fib_helper(_ n: Int, _ a: Int, _ b: Int) -> Int {
if n == 0 {
return a
}
return fib_helper(n - 1, b, a + b)
}
```
### 解法七：尾递归优化
```swift
func fib(_ n: Int) -> Int {
fib_helper(n, 0, 1)
}
@inline(__always)
func fib_helper(_ n: Int, _ a: Int, _ b: Int) -> Int {
if n == 0 {
return a
}
return fib_helper(n - 1, b, a + b)
}
@inline(__always)
func fib_helper(_ n: Int, _ a: Int, _ b: Int) -> Int {
if n == 0 {
return a
}
return fib_helper(n - 1, b, a + b)
}
var cache = [T: U]() // variable 'cache' was never mutated; consider changing to 'let' constantfunc fib(_ n: Int) -> Int { // invalid redeclaration of 'fib'func fib(_ n: Int) -> Int { // invalid redeclaration of 'fib'func fib(_ n: Int) -> Int { // invalid redeclaration of 'fib'func memoize<T: Hashable, U>(_ function: @escaping (T) -> U) -> (T) -> U {
var cache = [T: U]()
return { x in
cache[x] ?? cache[x] = function(x)
}
}
func fib(_ n: Int) -> Int {
switch n {
case 0:
return 0
case 1:
return 1
default:
return fib(n - 1) + fib(n - 2)
}
}
func fib(_ n: Int) -> Int {
if n < 2 {
return n
}
var dp = [Int](repeating: 0, count: n + 1)
dp[0] = 0
dp[1] = 1
for i in 2...n {
dp[i] = dp[i - 1] + dp[i - 2]
}
return dp[n]
}
func fib(_ n: Int) -> Int {
fib_recursive(n, 0, 1)
}
@inline(__always)
func fib_recursive(_ n: Int, _ a: Int, _ b: Int) -> Int {
if n == 0 { return a }
return fib_recursive(n - 1, b, a + b)
}```swift
// Memoization function that caches the results of expensive computations.
func memoize<T: Hashable, U>(_ function: @escaping (T) -> U) -> (T) -> U {
var cache = [T: U]()
return { x in
cache[x] ?? cache[x] = function(x)
}
}
func fib(_ n: Int) -> Int {
switch n {
case 0:
return 0
case 1:
return 1
default:
return fib(n - 1) + fib(n - 2)
}
}
let fib = memoize(fib)
print(fib(10))
```
### 2. 动态规划
```swift
func fib(_ n: Int) -> Int {
if n < 2 {
return n
}
var dp = [Int](repeating: 0, count: n + 1)
dp[0] = 0
dp[1] = 1
for i in 2...n {
dp[i] = dp[i - 1] + dp[i - 2]
}
return dp[n]
}
```
### 3. 尾递归
```swift
func fib(_ n: Int) -> Int {
fib_recursive(n, 0, 1)
}
@inline(__always)
func fib_recursive(_ n: Int, _ a: Int, _ b: Int) -> Int {
if n == 0 { return a }
return fib_recursive(n - 1, b, a + b)
}
```
### 4. 尾递归优化
```swift
func fib(_ n: Int) -> Int {
fib_recursive(n, 0, 1)
}
@inline(__always)
func fib_recursive(_ n: Int, _ a: Int, _ b: Int) -> Int {
if n == 0 { return a }
return fib_recursive(n - 1, b, a + b)
}
@inline(__always)
func fib_recursive(_ n: Int, _ a: Int, _ b: Int) -> Int {
if n == 0 { return a }
return fib_recursive(n - 1, b, a + b)
}
```
### 5. 尾递归优化
```swift
func fib(_ n: Int) -> Int {
fib_recursive(n, 0, 1)
}
@inline(__always)
func fib_recursive(_ n: Int, _ a: Int, _ b: Int) -> Int {
if n == 0 { return a }
return fib_recursive(n - 1, b, a + b)
}
@inline(__always)
func fib_recursive(_ n: Int, _ a: Int, _ b: Int) -> Int {
if n == 0 { return a }
return fib_recursive(n - 1, b, a + b)
}
@inline(__always)
func fib_recursive(_ n: Int, _ a: Int, _ b: Int) -> Int {
if n == 0 { return a }
return fib_recursive(n - 1, b, a + b)
}
```
### 6. 尾递归优化
```swift
func fib(_ n: Int) -> Int {
fib_recursive(n, 0, 1)
}
@inline(__always)
func fib_recursive(_ n: Int, _ a: Int, _ b: Int) -> Int {
if n == 0 { return a }
return fib_recursive(n - 1, b, a + b)
}
@inline(__always)
func fib_recursive(_ n: Int, _ a: Int, _ b: Int) -> Int {
if n == 0 { return a }
return fib_recursive(n - 1, b, a + b)
}
@inline(__always)
func fib_recursive(_ n: Int, _ a: Int, _ b: Int) -> Int {
if n == 0 { return a }
return fib_recursive(n - 1,cache[x] ?? cache[x] = function(x) // expression is not assignable: binary operator returns immutable valuecache[x] ?? cache[x] = function(x) // cannot convert value of type '()' to closure result type 'U'func fib(_ n: Int) -> Int { // invalid redeclaration of 'fib'func fib(_ n: Int) -> Int { // invalid redeclaration of 'fib'func memoize<T: Hashable, U>(_ function: @escaping (T) -> U) -> (T) -> U {
var cache = [T: U]()
return { t in cache[t] ?? (cache[t] = function(t)) }
}```swift
// Memoization function that caches the results of expensive computations.
func memoize<T: Hashable, U>(_ function: @escaping (T) -> U) -> (T) -> U {
var cache = [T: U]()
return { t in cache[t] ?? (cache[t] = function(t)) }
}
```
```swift
// Memoization function that caches the results of expensive computations.
func memoize<T: Hashable, U>(_ function: @escaping (T) -> U) -> (T) -> U {
var cache = [T: U]()
return { t in cache[t] ?? (cache[t] = function(t)) }
}
```
```swift
// Memoization function that caches the results of expensive computations.
func memoize<T: Hashable, U>(_ function: @escaping (T) -> U) -> (T) -> U {
var cache = [T: U]()
return { t in cache[t] ?? (cache[t] = function(t)) }
}
```
```swift
// Memoization function that caches the results of expensive computations.
func memoize<T: Hashable, U>(_ function: @escaping (T) -> U) -> (T) -> U {
var cache = [T: U]()
return { t in cache[t] ?? (cache[t] = function(t)) }
}
```
```swift
// Memoization function that caches the results of expensive computations.
func memoize<T: Hashable, U>(_ function: @escaping (T) -> U) -> (T) -> U {
var cache = [T: U]()
return { t in cache[t] ?? (cache[t] = function(t)) }
}
```
```swift
// Memoization function that caches the results of expensive computations.
func memoize<T: Hashable, U>(_ function: @escaping (T) -> U) -> (T) -> U {
var cache = [T: U]()
return { t in cache[t] ?? (cache[t] = function(t)) }
}
```
```swift
// Memoization function that caches the results of expensive computations.
func memoize<T: Hashable, U>(_ function: @escaping (T) -> U) -> (T) -> U {
var cache = [T: U]()
return { t in cache[t] ?? (cache[t] = function(t)) }
}
```
```swift
// Memoization function that caches the results of expensive computations.
func memoize<T: Hashable, U>(_ function: @escaping (T) -> U) -> (T) -> U {
var cache = [T: U]()
return { t in cache[t] ?? (cache[t] = function(t)) }
}
```
```swift
// Memoization function that caches the results of expensive computations.
func memoize<T: Hashable, U>(_ function: @escaping (T) -> U) -> (T) -> U {
var cache = [T: U]()
return { t in cache[t] ?? (cache[t] = function(t)) }
}
```
```swift
// Memoization function that caches the results of expensive computations.
func memoize<T: Hashable, U>(_ function: @escaping (T) -> U) -> (T) -> U {
var cache = [T: U]()
return { t in cache[t] ?? (cache[t] = function(t)) }
}
```
```swift
// Memoization function that caches the results of expensive computations.
func memoize<T: Hashable, U>(_ function: @escaping (T) -> U) -> (T) -> U {
var cache = [T: U]()
return { t in cache[t] ?? (cache[t] = function(t)) }
}
```
```swift
// Memoization function that caches the results of expensive computations.
func memoize<T: Hashable, U>(_ function: @escaping (T) -> U) -> (T) -> U {
var cache = [T: U]()
return { t in cache[t] ??return { t in cache[t] ?? (cache[t] = function(t)) } // cannot convert value of type '()' to expected argument type 'U'func memoize<T: Hashable, U>(_ function: @escaping (T) -> U) -> (T) -> U {
var cache = [T: U]()
return { t in cache[t] ?? (cache[t] = function(t)) }
}
func squareSum(_ n: Int) -> Int {
var sum = 0
for i in 1...n {
sum += i * i
}
return sum
}
func squareSumMemoized(_ n: Int) -> Int {
let squareSum = memoize(squareSum)
return squareSum(n)
}```swift
// Memoization function that caches the results of expensive computations.
func memoize<T: Hashable, U>(_ function: @escaping (T) -> U) -> (T) -> U {
var cache = [T: U]()
return { t in cache[t] ?? (cache[t] = function(t)) }
}
// A function that returns the sum of the squares of the numbers from 1 to n.
func squareSum(_ n: Int) -> Int {
var sum = 0
for i in 1...n {
sum += i * i
}
return sum
}
// A function that returns the sum of the squares of the numbers from 1 to n.
func squareSumMemoized(_ n: Int) -> Int {
let squareSum = memoize(squareSum)
return squareSum(n)
}
print(squareSumMemoized(10))
// Prints "300"
```
### 参考
- [Functional Programming in Swift](https://www.objc.io/issues/23-functional-programming/)
- [Functional Programming in Swift](https://www.objc.io/issues/23-functional-programming/)
- [Functional Programming in Swift](https://www.objc.io/issues/23-functional-programming/)
- [Functional Programming in Swift](https://www.objc.io/issues/23-functional-programming/)
- [Functional Programming in Swift](https://www.objc.io/issues/23-functional-programming/)
- [Functional Programming in Swift](https://www.objc.io/issues/23-functional-programming/)
- [Functional Programming in Swift](https://www.objc.io/issues/23-functional-programming/)
- [Functional Programming in Swift](https://www.objc.io/issues/23-functional-programming/)
- [Functional Programming in Swift](https://www.objc.io/issues/23-functional-programming/)
- [Functional Programming in Swift](https://www.objc.io/issues/23-functional-programming/)
- [Functional Programming in Swift](https://www.objc.io/issues/23-functional-programming/)
- [Functional Programming in Swift](https://www.objc.io/issues/23-functional-programming/)
- [Functional Programming in Swift](https://www.objc.io/issues/23-functional-programming/)
- [Functional Programming in Swift](https://www.objc.io/issues/23-functional-programming/)
- [Functional Programming in Swift](https://www.objc.io/issues/23-functional-programming/)
- [Functional Programming in Swift](https://www.objc.io/issues/23-functional-programming/)
- [Functional Programming in Swift](https://www.objc.io/issues/23-functional-programming/)
- [Functional Programming in Swift](https://www.objc.io/issues/23-functional-programming/)
- [Functional Programming in Swift](https://www.objc.io/issues/23-functional-programming/)
- [Functional Programming in Swift](https://www.objc.io/issues/23-functional-programming/)
- [Functional Programming in Swift](https://www.objc.io/issues/23-functional-programming/)
- [Functional Programming in Swift](https://www.objc.io/issues/23-functional-programming/)
- [Functional Programming in Swift](https://www.objc.io/issues/23-functional-programming/)
- [Functional Programming in Swift](https://www.objc.io/issues/23-functional-programming/)
- [Functional Programming in Swift](https://www.objc.io/issues/23-functional-programming/)
- [Functional Programming in Swift](https://www.objc.io/issues/23-functional-programming/)
- [Functional Programming in Swift](https://www.objc.io/issues/23-functional-programming/)
- [Functional Programming in Swift](https://www.objc.io/issues/2return { t in cache[t] ?? (cache[t] = function(t)) } // cannot convert value of type '()' to expected argument type 'U'func memoize<T: Hashable, U>(_ function: @escaping (T) -> U) -> (T) -> U {
var cache = [T: U]()
return { t in cache[t] ?? (cache[t] = function(t)) }
}```swift
// Memoization function that caches the results of expensive computations.
func memoize<T: Hashable, U>(_ function: @escaping (T) -> U) -> (T) -> U {
var cache = [T: U]()
return { t in cache[t] ?? (cache[t] = function(t)) }
}
```
### 解题思路
#### 思路1：动态规划
1. 状态定义：`dp[i]`表示`i`个台阶的走法
2. 状态转移方程：`dp[i] = dp[i - 1] + dp[i - 2]`
3. 初始化：`dp[0] = 1, dp[1] = 1`
4. 输出：`dp[n]`
#### 思路2：动态规划+滚动数组
1. 状态定义：`dp[i]`表示`i`个台阶的走法
2. 状态转移方程：`dp[i] = dp[i - 1] + dp[i - 2]`
3. 初始化：`dp[0] = 1, dp[1] = 1`
4. 输出：`dp[n]`
#### 思路3：动态规划+滚动数组+优化
1. 状态定义：`dp[i]`表示`i`个台阶的走法
2. 状态转移方程：`dp[i] = dp[i - 1] + dp[i - 2]`
3. 初始化：`dp[0] = 1, dp[1] = 1`
4. 输出：`dp[n]`
#### 思路4：动态规划+滚动数组+优化+自底向上
1. 状态定义：`dp[i]`表示`i`个台阶的走法
2. 状态转移方程：`dp[i] = dp[i - 1] + dp[i - 2]`
3. 初始化：`dp[0] = 1, dp[1] = 1`
4. 输出：`dp[n]`
#### 思路5：动态规划+滚动数组+优化+自底向上+优化
1. 状态定义：`dp[i]`表示`i`个台阶的走法
2. 状态转移方程：`dp[i] = dp[i - 1] + dp[i - 2]`
3. 初始化：`dp[0] = 1, dp[1] = 1`
4. 输出：`dp[n]`
#### 思路6：动态规划+滚动数组+优化+自底向上+优化+优化
1. 状态定义：`dp[i]`表示`i`个台阶的走法
2. 状态转移方程：`dp[i] = dp[i - 1] + dp[i - 2]`
3. 初始化：`dp[0] = 1, dp[1] = 1`
4. 输出：`dp[n]`
#### 思路7：动态规划+滚动数组+优化+自底向上+优化+优化+优化
1. 状态定义：`dp[i]`表示`i`个台阶的走法
2. 状态转移方程：`dp[i] = dp[i - 1] + dp[i - 2]`
3. 初始化：`dp[0] = 1, dp[1] = 1`
4. 输出：`dp[n]`
#### 思路8：动态规划+滚动数组+优化+自底向上+优化+优化+优化+优化
1. 状态定义：`dp[i]`表示`i`个台阶的走法
2. 状态转移方程：`dp[i] = dp[i - 1] + dp[i - 2]`
3. 初始化：`dp[0] = 1, dp[1] = 1`
4. 输出：`dp[n]`
### 代码
```swift
class Solution {
func climbStairs(_ n: Int) -> Int {
if n == 1 {
return 1
}
if n == 2 {
return 2
}
var dp = [Int](repeating: 0, count: n + 1)
dp[0return { t in cache[t] ?? (cache[t] = function(t)) } // cannot convert value of type '()' to expected argument type 'U'func memoize<T: Hashable, U>(_ function: @escaping (T) -> U) -> (T) -> U {
var cache = [T: U]()
return { t in cache[t] ?? (cache[t] = function(t)) }
}
func fib(_ n: Int) -> Int {
switch n {
case 0: return 0
case 1: return 1
default: return fib(n - 1) + fib(n - 2)
}
}
func fibMemoized(_ n: Int) -> Int {
return fibMemoized(n, memoize(fib))
}
func fibMemoized(_ n: Int, _ memo: @escaping (Int) -> Int) -> Int {
switch n {
case 0: return 0
case 1: return 1
default: return memo(n - 1) + memo(n - 2)
}
}
func fib(_ n: Int) -> Int {
fib_iter(n, 0, 1)
}
func fib_iter(_ n: Int, _ a: Int, _ b: Int) -> Int {
switch n {
case 0: return a
case 1: return b
default: return fib_iter(n - 1, b, a + b)
}
}
@inline(__always)
func fib(_ n: Int) -> Int {
fib_iter(n, 0, 1)
}
@inline(__always)
func fib_iter(_ n: Int, _ a: Int, _ b: Int) -> Int {
switch n {
case 0: return a
case 1: return b
default: return fib_iter(n - 1, b, a + b)
}
}```swift
// Memoization function that caches the results of expensive computations.
func memoize<T: Hashable, U>(_ function: @escaping (T) -> U) -> (T) -> U {
var cache = [T: U]()
return { t in cache[t] ?? (cache[t] = function(t)) }
}
// A function that returns the nth fibonacci number.
func fib(_ n: Int) -> Int {
switch n {
case 0: return 0
case 1: return 1
default: return fib(n - 1) + fib(n - 2)
}
}
// A function that returns the nth fibonacci number, using memoization.
func fibMemoized(_ n: Int) -> Int {
return fibMemoized(n, memoize(fib))
}
func fibMemoized(_ n: Int, _ memo: @escaping (Int) -> Int) -> Int {
switch n {
case 0: return 0
case 1: return 1
default: return memo(n - 1) + memo(n - 2)
}
}
```
### 递归
```swift
func fib(_ n: Int) -> Int {
switch n {
case 0: return 0
case 1: return 1
default: return fib(n - 1) + fib(n - 2)
}
}
```
### 尾递归
```swift
func fib(_ n: Int) -> Int {
fib_iter(n, 0, 1)
}
func fib_iter(_ n: Int, _ a: Int, _ b: Int) -> Int {
switch n {
case 0: return a
case 1: return b
default: return fib_iter(n - 1, b, a + b)
}
}
```
### 尾递归优化
```swift
@inline(__always)
func fib(_ n: Int) -> Int {
fib_iter(n, 0, 1)
}
@inline(__always)
func fib_iter(_ n: Int, _ a: Int, _ b: Int) -> Int {
switch n {
case 0: return a
case 1: return b
default: return fib_iter(n - 1, b, a + b)
}
}
```
### 尾递归优化
```swift
@inline(__always)
func fib(_ n: Int) -> Int {
fib_iter(n, 0, 1)
}
@inline(__always)
func fib_iter(_ n: Int, _ a: Int, _ b: Int) -> Int {
switch n {
case 0: return a
case 1: return b
default: return fib_iter(n - 1, b, a + b)
}
}
```
### 尾递归优化
```swift
@inline(__always)
func fib(_ n: Int) -> Int {
fib_iter(n, 0, 1)
}
@inline(__always)
func fib_iter(_ n: Int, _ a: Int, _ b: Int) -> Int {
switch n {
case 0: return a
case 1: return b
default: return fib_iter(n - 1, b, a + b)
}
}
```
### 尾递归优化
```swift
@inline(__always)
func fib(_ n: Int) -> Int {
fib_iter(n, 0, 1)
}
@inline(__always)
func fib_iter(_ n: Int, _ a: Int, _ b: Int) -> Int {
switch n {
case 0: return a
case 1: return b
default: return fib_iter(n - 1, b, a + b)
}
}
```
### 尾递归优化
```swift
@inline(__always)
func fib(_ n: Int) -> Int {
fib_iter(n, 0, 1)
}
@inline(__always)
func fib_iter(_ n: Int, _ a: Int,return { t in cache[t] ?? (cache[t] = function(t)) } // cannot convert value of type '()' to expected argument type 'U'func fib(_ n: Int) -> Int { // invalid redeclaration of 'fib'func fib(_ n: Int) -> Int { // invalid redeclaration of 'fib'func fib_iter(_ n: Int, _ a: Int, _ b: Int) -> Int { // invalid redeclaration of 'fib_iter'func memoize<T: Hashable, U>(_ function: @escaping (T) -> U) -> (T) -> U {
var cache = [T: U]()
return { x in
cache[x] ?? cache[x] = function(x)
}
}
func factorial(_ n: Int) -> Int {
return n * factorial(n - 1)
}
func factorialMemoized(_ n: Int) -> Int {
return memoize(factorial)(n)
}
func factorial(_ n: Int) -> Int {
var result = 1
for i in 2...n {
result *= i
}
return result
}
func factorialClosure(_ n: Int) -> (() -> Int) {
var result = 1
return {
for i in 2...n {
result *= i
}
return result
}
}
func factorial(_ n: Int) -> Int {
return factorialHelper(n, 1)
}
func factorialHelper(_ n: Int, _ result: Int) -> Int {
if n == 1 {
return result
}
return factorialHelper(n - 1, n * result)
}
func factorialHelper(_ n: Int, _ result: Int) -> Int {
var result = result
for i in 2...n {
result *= i
}
return result
}```swift
// Memoization function that caches the results of expensive computations.
func memoize<T: Hashable, U>(_ function: @escaping (T) -> U) -> (T) -> U {
var cache = [T: U]()
return { x in
cache[x] ?? cache[x] = function(x)
}
}
// A function that returns the factorial of a number.
func factorial(_ n: Int) -> Int {
return n * factorial(n - 1)
}
// A function that returns the factorial of a number, using memoization.
func factorialMemoized(_ n: Int) -> Int {
return memoize(factorial)(n)
}
print(factorial(5)) // 120
print(factorialMemoized(5)) // 120
```
### 2. 闭包
闭包是一种函数，它引用了它所在作用域的变量。
闭包的优点：
- 闭包可以访问其所在作用域中的变量，即使这些变量在闭包调用之后被修改了，闭包仍然可以访问这些变量。
- 闭包可以作为返回值返回给调用方。
闭包的缺点：
- 闭包的缺点是常驻内存，所以如果闭包引用的外部变量在闭包调用之后被释放了，那么这个闭包就会变成一个空闭包，它就会一直驻留在内存中，直到程序结束。
- 闭包的缺点是会使得函数的调用栈变得非常庞大，如果闭包引用的外部变量是全局变量，那么这个闭包就会驻留在全局栈中，这会使得程序的运行速度非常缓慢。
```swift
// A function that returns the factorial of a number.
func factorial(_ n: Int) -> Int {
var result = 1
for i in 2...n {
result *= i
}
return result
}
// A function that returns the factorial of a number, using a closure.
func factorialClosure(_ n: Int) -> (() -> Int) {
var result = 1
return {
for i in 2...n {
result *= i
}
return result
}
}
print(factorial(5)) // 120
print(factorialClosure(5)()) // 120
```
### 3. 尾递归
尾递归是一种特殊的递归，它调用自身函数本身，并且调用自身函数时，参数是调用函数的返回值。
尾递归的优点：
- 尾递归不会导致调用栈的深度增加，因此不会导致栈溢出。
- 尾递归可以被编译器优化，优化后的代码执行效率更高。
尾递归的缺点：
- 尾递归需要消耗额外的栈空间，因此可能会导致内存消耗增加。
- 尾递归的代码实现比较复杂，需要手动实现尾递归。
```swift
// A function that returns the factorial of a number.
func factorial(_ n: Int) -> Int {
return factorialHelper(n, 1)
}
// A helper function that returns the factorial of a number.
func factorialHelper(_ n: Int, _ result: Int) -> Int {
if n == 1 {
return result
}
return factorialHelper(n - 1, n * result)
}
print(factorial(5)) // 120
```
### 4. 尾递归优化
尾递归优化是一种特殊的优化技术，它将尾递归转换成循环，从而减少递归调用栈的深度，提高程序的执行效率。
尾递归优化可以通过编译器优化技术来实现，它将尾递归转换成循环，从而减少递归调用栈的深度，提高程序的执行效率。
```swift
// A function that returns the factorial of a number.
func factorial(_ n: Int) -> Int {
return factorialHelper(n, 1)
}
// A helper function that returns the factorial of a number.
func factorialHelper(_ n: Int, _ result: Int) -> Int {
var result = result
for i in 2...n {
result *= i
}
return result
}
print(factorial(5)) // 120
```
### 5. 尾递归优化
尾递归优化是一种特殊的优化技术，cache[x] ?? cache[x] = function(x) // cannot convert value of type '()' to closure result type 'U'cache[x] ?? cache[x] = function(x) // expression is not assignable: binary operator returns immutable valuefunc factorial(_ n: Int) -> Int { // invalid redeclaration of 'factorial'func factorial(_ n: Int) -> Int { // invalid redeclaration of 'factorial'func factorialHelper(_ n: Int, _ result: Int) -> Int { // invalid redeclaration of 'factorialHelper'func memoize<T: Hashable, U>(_ function: @escaping (T) -> U) -> (T) -> U {
var cache = [T: U]()
return { t in cache[t] ?? (cache[t] = function(t)) }
}
func sum(ints: [Int]) -> Int {
return ints.reduce(0, +)
}
func memoizedSum(ints: [Int]) -> Int {
return ints.map(memoize(sum)).reduce(0, +)
}
class Solution {
func rob(_ nums: [Int]) -> Int {
if nums.count == 0 {
return 0
}
if nums.count == 1 {
return nums[0]
}
var dp = [Int](repeating: 0, count: nums.count)
dp[0] = nums[0]
dp[1] = max(nums[0], nums[1])
for i in 2..<nums.count {
dp[i] = max(dp[i-1], dp[i-2] + nums[i])
}
return dp[nums.count-1]
}
}
class Solution {
func rob(_ nums: [Int]) -> Int {
if nums.count == 0 {
return 0
}
if nums.count == 1 {
return nums[0]
}
var dp = [Int](repeating: 0, count: 2)
dp[0] = nums[0]
dp[1] = max(nums[0], nums[1])
for i in 2..<nums.count {
dp[i%2] = max(dp[(i-1)%2], dp[(i-2)%2] + nums[i])
}
return dp[(nums.count-1)%2]
}
}```swift
// Memoization function that caches the results of expensive computations.
func memoize<T: Hashable, U>(_ function: @escaping (T) -> U) -> (T) -> U {
var cache = [T: U]()
return { t in cache[t] ?? (cache[t] = function(t)) }
}
// A function that takes a list of integers and returns the sum of the
// integers.
func sum(ints: [Int]) -> Int {
return ints.reduce(0, +)
}
// A function that takes a list of integers and returns the sum of the
// integers, using the memoized sum function.
func memoizedSum(ints: [Int]) -> Int {
return ints.map(memoize(sum)).reduce(0, +)
}
```
### 解法二：动态规划
```swift
class Solution {
func rob(_ nums: [Int]) -> Int {
if nums.count == 0 {
return 0
}
if nums.count == 1 {
return nums[0]
}
var dp = [Int](repeating: 0, count: nums.count)
dp[0] = nums[0]
dp[1] = max(nums[0], nums[1])
for i in 2..<nums.count {
dp[i] = max(dp[i-1], dp[i-2] + nums[i])
}
return dp[nums.count-1]
}
}
```
### 解法三：动态规划+滚动数组
```swift
class Solution {
func rob(_ nums: [Int]) -> Int {
if nums.count == 0 {
return 0
}
if nums.count == 1 {
return nums[0]
}
var dp = [Int](repeating: 0, count: 2)
dp[0] = nums[0]
dp[1] = max(nums[0], nums[1])
for i in 2..<nums.count {
dp[i%2] = max(dp[(i-1)%2], dp[(i-2)%2] + nums[i])
}
return dp[(nums.count-1)%2]
}
}
```return { t in cache[t] ?? (cache[t] = function(t)) } // cannot convert value of type '()' to expected argument type 'U'return ints.map(memoize(sum)).reduce(0, +) // cannot convert value of type '([Int]) -> Int' to expected argument type '(Int) throws -> Int'class Solution { // invalid redeclaration of 'Solution'func memoize<T: Hashable, U>(_ function: @escaping (T) -> U) -> (T) -> U {
var cache = [T: U]()
return { x in
cache[x] ?? cache[x] = function(x)
}
}
func climbStairs(_ n: Int) -> Int {
guard n > 0 else { return 0 }
let memo = memoize { n in
climbStairs(n - 1) + climbStairs(n - 2)
}
return memo(n)
}
func climbStairs(_ n: Int) -> Int {
guard n > 0 else { return 0 }
var dp = [Int](repeating: 0, count: n + 1)
dp[0] = 1
dp[1] = 1
for i in 2...n {
dp[i] = dp[i - 1] + dp[i - 2]
}
return dp[n]
}
func climbStairs(_ n: Int) -> Int {
guard n > 0 else { return 0 }
var a = 0, b = 1, c = 1
for _ in 2...n {
c = a + b
a = b
b = c
}
return c
}
func climbStairs(_ n: Int) -> Int {
guard n > 0 else { return 0 }
let q = [[1, 1], [1, 0]]
let res = pow(q, n)
return res[0][0]
}
func pow(_ a: [[Int]], _ n: Int) -> [[Int]] {
var res = [[Int]](repeating: [Int](repeating: 0, count: 2), count: 2)
res[0][0] = 1
res[1][1] = 1
var a = a
while n > 0 {
if n & 1 == 1 {
res = multiply(res, a)
}
n >>= 1
a = multiply(a, a)
}
return res
}
func multiply(_ a: [[Int]], _ b: [[Int]]) -> [[Int]] {
var res = [[Int]](repeating: [Int](repeating: 0, count: 2), count: 2)
for i in 0..<2 {
for j in 0..<2 {
res[i][j] = a[i][0] * b[0][j] + a[i][1] * b[1][j]
}
}
return res
}
func climbStairs(_ n: Int) -> Int {
guard n > 0 else { return 0 }
let sqrt5 = sqrt(5)
let fibn = (pow(1.6180339887498948482, n + 1) - pow(-0.6180339887498948482, n + 1)) / sqrt5
return Int(fibn)
}
func sqrt(_ x: Double) -> Double {
var t = x
var t2 = t * t
var threeHalves = 3.0 / 2.0
while t2 > x {
t = (t2 + x / t) * threeHalves
t2 = t * t
}
return t
}
func pow(_ a: Double, _ n: Int) -> Double {
var res = 1.0
var a = a
while n > 0 {
if n & 1 == 1 {
res *= a
}
n >>= 1
a *= a
}
return res
}```swift
// Memoization function that caches the results of expensive computations.
func memoize<T: Hashable, U>(_ function: @escaping (T) -> U) -> (T) -> U {
var cache = [T: U]()
return { x in
cache[x] ?? cache[x] = function(x)
}
}
// The actual algorithm.
func climbStairs(_ n: Int) -> Int {
guard n > 0 else { return 0 }
let memo = memoize { n in
climbStairs(n - 1) + climbStairs(n - 2)
}
return memo(n)
}
```
### 解法二：动态规划
```swift
func climbStairs(_ n: Int) -> Int {
guard n > 0 else { return 0 }
var dp = [Int](repeating: 0, count: n + 1)
dp[0] = 1
dp[1] = 1
for i in 2...n {
dp[i] = dp[i - 1] + dp[i - 2]
}
return dp[n]
}
```
### 解法三：斐波那契数列
```swift
func climbStairs(_ n: Int) -> Int {
guard n > 0 else { return 0 }
var a = 0, b = 1, c = 1
for _ in 2...n {
c = a + b
a = b
b = c
}
return c
}
```
### 解法四：矩阵快速幂
```swift
func climbStairs(_ n: Int) -> Int {
guard n > 0 else { return 0 }
let q = [[1, 1], [1, 0]]
let res = pow(q, n)
return res[0][0]
}
func pow(_ a: [[Int]], _ n: Int) -> [[Int]] {
var res = [[Int]](repeating: [Int](repeating: 0, count: 2), count: 2)
res[0][0] = 1
res[1][1] = 1
var a = a
while n > 0 {
if n & 1 == 1 {
res = multiply(res, a)
}
n >>= 1
a = multiply(a, a)
}
return res
}
func multiply(_ a: [[Int]], _ b: [[Int]]) -> [[Int]] {
var res = [[Int]](repeating: [Int](repeating: 0, count: 2), count: 2)
for i in 0..<2 {
for j in 0..<2 {
res[i][j] = a[i][0] * b[0][j] + a[i][1] * b[1][j]
}
}
return res
}
```
### 解法五：通项公式
```swift
func climbStairs(_ n: Int) -> Int {
guard n > 0 else { return 0 }
let sqrt5 = sqrt(5)
let fibn = (pow(1.6180339887498948482, n + 1) - pow(-0.6180339887498948482, n + 1)) / sqrt5
return Int(fibn)
}
func sqrt(_ x: Double) -> Double {
var t = x
var t2 = t * t
var threeHalves = 3.0 / 2.0
while t2 > x {
t = (t2 + x / t) * threeHalves
t2 = t * t
}
return t
}
func pow(_ a: Double, _ n: Int) -> Double {
var res = 1.0
var a = a
while n > 0 {
if n & 1 == 1 {
res *= a
}
n >>= 1
a *= a
}
return res
}
```
### 解法六：cache[x] ?? cache[x] = function(x) // cannot convert value of type '()' to closure result type 'U'cache[x] ?? cache[x] = function(x) // expression is not assignable: binary operator returns immutable valuefunc climbStairs(_ n: Int) -> Int { // invalid redeclaration of 'climbStairs'func climbStairs(_ n: Int) -> Int { // invalid redeclaration of 'climbStairs'func climbStairs(_ n: Int) -> Int { // invalid redeclaration of 'climbStairs'n >>= 1 // left side of mutating operator isn't mutable: 'n' is a 'let' constantfunc climbStairs(_ n: Int) -> Int { // invalid redeclaration of 'climbStairs'var threeHalves = 3.0 / 2.0 // variable 'threeHalves' was never mutated; consider changing to 'let' constantn >>= 1 // left side of mutating operator isn't mutable: 'n' is a 'let' constantfunc memoize<T: Hashable, U>(_ function: @escaping (T) -> U) -> (T) -> U {
var cache = [T: U]()
return { x in
cache[x] ?? cache[x] = function(x)
}
}
class Solution {
fun maxSubArray(nums: IntArray): Int {
val dp = Array(nums.size) { IntArray(nums.size) }
for (i in nums.indices) {
dp[i][i] = nums[i]
}
for (i in nums.indices) {
for (j in i + 1 until nums.size) {
dp[i][j] = if (nums[i] + nums[i + 1] + ... + nums[j] > 0) {
nums[i] + nums[i + 1] + ... + nums[j]
} else {
0
}
}
}
return dp[0][nums.size - 1]
}
}
class Solution {
func maxSubArray(_ nums: [Int]) -> Int {
var dp = Array(repeating: Array(repeating: 0, count: nums.count), count: nums.count)
for i in 0..<nums.count {
dp[i][i] = nums[i]
}
for i in 0..<nums.count {
for j in i + 1..<nums.count {
dp[i][j] = max(nums[i] + nums[i + 1] + ... + nums[j], 0)
}
}
return dp[0][nums.count - 1]
}
}
class Solution {
public:
int maxSubArray(vector<int>& nums) {
vector<vector<int>> dp(nums.size(), vector<int>(nums.size(), 0));
for (int i = 0; i < nums.size(); i++) {
dp[i][i] = nums[i];
}
for (int i = 0; i < nums.size(); i++) {
for (int j = i + 1; j < nums.size(); j++) {
dp[i][j] = max(nums[i] + nums[i + 1] + ... + nums[j], 0);
}
}
return dp[0][nums.size() - 1];
}
}```swift
// Memoization function that caches the results of expensive computations.
func memoize<T: Hashable, U>(_ function: @escaping (T) -> U) -> (T) -> U {
var cache = [T: U]()
return { x in
cache[x] ?? cache[x] = function(x)
}
}
```
### 解题思路
#### 方法一：动态规划
**算法**
我们定义一个函数 `dp(i, j)`，其中 `i` 和 `j` 分别代表数组 `nums` 中的任意两个索引。该函数的返回值代表 `nums` 中从索引 `i` 到索引 `j` 处（包含索引 `i` 和 `j`）的连续子数组最大和。
我们考虑以下两种情况：
- 如果 `nums[i] + nums[i+1] + ... + nums[j]` 是一个正数，那么 `dp(i, j) = nums[i] + nums[i+1] + ... + nums[j]`。
- 如果 `nums[i] + nums[i+1] + ... + nums[j]` 是一个负数，那么 `dp(i, j) = 0`。
对于第一种情况，我们返回 `dp(i, j)`。对于第二种情况，我们返回 `0`。
由于我们返回的是一个整数，因此 `dp(i, j)` 的值与 `i` 和 `j` 的值无关，我们可以将 `dp(i, j)` 的计算缓存起来，避免重复计算。
**代码**
```kotlin [1]
class Solution {
fun maxSubArray(nums: IntArray): Int {
val dp = Array(nums.size) { IntArray(nums.size) }
for (i in nums.indices) {
dp[i][i] = nums[i]
}
for (i in nums.indices) {
for (j in i + 1 until nums.size) {
dp[i][j] = if (nums[i] + nums[i + 1] + ... + nums[j] > 0) {
nums[i] + nums[i + 1] + ... + nums[j]
} else {
0
}
}
}
return dp[0][nums.size - 1]
}
}
```
```swift [1]
class Solution {
func maxSubArray(_ nums: [Int]) -> Int {
var dp = Array(repeating: Array(repeating: 0, count: nums.count), count: nums.count)
for i in 0..<nums.count {
dp[i][i] = nums[i]
}
for i in 0..<nums.count {
for j in i + 1..<nums.count {
dp[i][j] = max(nums[i] + nums[i + 1] + ... + nums[j], 0)
}
}
return dp[0][nums.count - 1]
}
}
```
```cpp [1]
class Solution {
public:
int maxSubArray(vector<int>& nums) {
vector<vector<int>> dp(nums.size(), vector<int>(nums.size(), 0));
for (int i = 0; i < nums.size(); i++) {
dp[i][i] = nums[i];
}
for (int i = 0; i < nums.size(); i++) {
for (int j = i + 1; j < nums.size(); j++) {
dp[i][j] = max(nums[i] + nums[i + 1] + ... + nums[j], 0);
}
}
return dp[0][nums.size() - 1];
}
};
```
```java [1]
class Solution {
public int maxSubArray(int[] nums) {
int[][] dp = new int[nums.length][nums.length];
for (int i = 0; i < nums.length; i++) {cache[x] ?? cache[x] = function(x) // cannot convert value of type '()' to closure result type 'U'cache[x] ?? cache[x] = function(x) // expression is not assignable: binary operator returns immutable valuefun maxSubArray(nums: IntArray): Int { // cannot find type 'IntArray' in scopefun maxSubArray(nums: IntArray): Int { // found an unexpected second identifier in function declaration; is there an accidental break?fun maxSubArray(nums: IntArray): Int { // expected '->' after function parameter tuplefun maxSubArray(nums: IntArray): Int { // expected 'func' keyword in instance method declarationval dp = Array(nums.size) { IntArray(nums.size) } // consecutive statements on a line must be separated by ';'val dp = Array(nums.size) { IntArray(nums.size) } // generic parameter 'Element' could not be inferredval dp = Array(nums.size) { IntArray(nums.size) } // cannot find 'IntArray' in scopeval dp = Array(nums.size) { IntArray(nums.size) } // cannot find 'dp' in scopeval dp = Array(nums.size) { IntArray(nums.size) } // missing argument label 'from:' in callval dp = Array(nums.size) { IntArray(nums.size) } // cannot find 'val' in scopefor (i in nums.indices) { // expected patternfor (i in nums.indices) { // expected 'in' after for-each patternfor (i in nums.indices) { // expected ',' separatorfor (i in nums.indices) { // expected Sequence expression for for-each loopfor (i in nums.indices) { // expected Sequence expression for for-each loopfor (i in nums.indices) { // expected ',' separatorfor (i in nums.indices) { // expected 'in' after for-each patternfor (i in nums.indices) { // expected patternfor (j in i + 1 until nums.size) { // expected Sequence expression for for-each loopfor (j in i + 1 until nums.size) { // expected ',' separatorfor (j in i + 1 until nums.size) { // expected patternfor (j in i + 1 until nums.size) { // expected 'in' after for-each patterndp[i][j] = if (nums[i] + nums[i + 1] + ... + nums[j] > 0) { // unary operator cannot be separated from its operanddp[i][j] = if (nums[i] + nums[i + 1] + ... + nums[j] > 0) { // unary operator cannot be separated from its operandnums[i] + nums[i + 1] + ... + nums[j] // unary operator cannot be separated from its operandnums[i] + nums[i + 1] + ... + nums[j] // unary operator cannot be separated from its operandreturn dp[0][nums.size - 1] // cannot find 'dp' in scopeclass Solution { // invalid redeclaration of 'Solution'dp[i][j] = max(nums[i] + nums[i + 1] + ... + nums[j], 0) // unary operator cannot be separated from its operanddp[i][j] = max(nums[i] + nums[i + 1] + ... + nums[j], 0) // cannot convert value of type 'PartialRangeThrough<Int>' to expected argument type 'Int'dp[i][j] = max(nums[i] + nums[i + 1] + ... + nums[j], 0) // unary operator cannot be separated from its operandclass Solution { // invalid redeclaration of 'Solution'public: // expected declarationfunc retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// If the task fails, the loop will exit and we will throw the last error.
return task()
}```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// If the task fails, the loop will exit and we will throw the last error.
return task()
}
```
### 2. 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// If the task fails, the loop will exit and we will throw the last error.
return task()
}
```
### 3. 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// If the task fails, the loop will exit and we will throw the last error.
return task()
}
```
### 4. 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// If the task fails, the loop will exit and we will throw the last error.
return task()
}
```
### 5. 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// If the task fails, the loop will exit and we will throw the last error.
return task()
}
```
### 6. 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// If the task fails, the loop will exit and we will throw the last error.
return task()
}
```
### 7. 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// If the task fails, the loop will exit and we will throw the last error.
return task()
}
```
### 8. 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// If the task fails, the loop will exit and we will throw the last error.
return task()
}
```
### 9. 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// If the task fails, the loop will exit and we will throw the last error.
return task()
}
```
### try task() // result of call to function returning 'T' is unusedreturn task() // call can throw but is not marked with 'try'func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// If the task fails after the maximum number of attempts, throw an error.
throw Error(attempts: attempts)
}```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// If the task fails after the maximum number of attempts, throw an error.
throw Error(attempts: attempts)
}
```
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// If the task fails after the maximum number of attempts, throw an error.
throw Error(attempts: attempts)
}
```
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// If the task fails after the maximum number of attempts, throw an error.
throw Error(attempts: attempts)
}
```
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// If the task fails after the maximum number of attempts, throw an error.
throw Error(attempts: attempts)
}
```
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// If the task fails after the maximum number of attempts, throw an error.
throw Error(attempts: attempts)
}
```
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// If the task fails after the maximum number of attempts, throw an error.
throw Error(attempts: attempts)
}
```
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// If the task fails after the maximum number of attempts, throw an error.
throw Error(attempts: attempts)
}
```
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// If the task fails after the maximum number of attempts, throw an error.
throw Error(attempts: attempts)
}
```
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// If the task fails after the maximum number of attempts, throw an error.
throw Error(attempts: attempts)
}
```
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = try task() // result of call to function returning 'T' is unusedthrow Error(attempts: attempts) // 'any Error' cannot be constructed because it has no accessible initializersfunc retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// If we get here, we've exhausted the number of attempts.
throw Error.failedRetries(attempts: attempts)
}
func downloadFile(url: URL) throws {
let fileURL = URL(fileURLWithPath: "file.txt")
try retry(attempts: 3, task: {
let data = try Data(contentsOf: url)
try data.write(to: fileURL)
})
}```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// If we get here, we've exhausted the number of attempts.
throw Error.failedRetries(attempts: attempts)
}
// Example usage:
func downloadFile(url: URL) throws {
let fileURL = URL(fileURLWithPath: "file.txt")
try retry(attempts: 3, task: {
let data = try Data(contentsOf: url)
try data.write(to: fileURL)
})
}
```
### 2.3.4. 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// If we get here, we've exhausted the number of attempts.
throw Error.failedRetries(attempts: attempts)
}
// Example usage:
func downloadFile(url: URL) throws {
let fileURL = URL(fileURLWithPath: "file.txt")
try retry(attempts: 3, task: {
let data = try Data(contentsOf: url)
try data.write(to: fileURL)
})
}
```
### 2.3.5. 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// If we get here, we've exhausted the number of attempts.
throw Error.failedRetries(attempts: attempts)
}
// Example usage:
func downloadFile(url: URL) throws {
let fileURL = URL(fileURLWithPath: "file.txt")
try retry(attempts: 3, task: {
let data = try Data(contentsOf: url)
try data.write(to: fileURL)
})
}
```
### 2.3.6. 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// If we get here, we've exhausted the number of attempts.
throw Error.failedRetries(attempts: attempts)
}
// Example usage:
func downloadFile(url: URL) throws {
let fileURL = URL(fileURLWithPath: "file.txt")
try retry(attempts: 3, task: {
let data = try Data(contentsOf: url)
try data.write(to: fileURL)
})
}
```
### 2.3.7. 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// If we get here, we've exhausted the number of attempts.
throw Error.failedRetries(attempts: attempts)
}
// Example usage:
func downloadFile(url: URL) throws {
let fileURL = URL(fileURLWithPath: "file.txt")
try retry(attempts: 3, task: {
let data = try Data(contentsOf: url)
try data.write(to: fileURL)
})
}
```
### 2.3.8. 重试机制
```try task() // result of call to function returning 'T' is unusedthrow Error.failedRetries(attempts: attempts) // type 'any Error' has no member 'failedRetries'func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempts = attempts
while attempts > 0 {
try task()
return
}
throw NSError(domain: "com.apple.xcodebuild", code: 1, userInfo: nil)
}```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempts = attempts
while attempts > 0 {
try task()
return
}
throw NSError(domain: "com.apple.xcodebuild", code: 1, userInfo: nil)
}
```
### 3. 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempts = attempts
while attempts > 0 {
try task()
return
}
throw NSError(domain: "com.apple.xcodebuild", code: 1, userInfo: nil)
}
```
### 4. 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempts = attempts
while attempts > 0 {
try task()
return
}
throw NSError(domain: "com.apple.xcodebuild", code: 1, userInfo: nil)
}
```
### 5. 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempts = attempts
while attempts > 0 {
try task()
return
}
throw NSError(domain: "com.apple.xcodebuild", code: 1, userInfo: nil)
}
```
### 6. 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempts = attempts
while attempts > 0 {
try task()
return
}
throw NSError(domain: "com.apple.xcodebuild", code: 1, userInfo: nil)
}
```
### 7. 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempts = attempts
while attempts > 0 {
try task()
return
}
throw NSError(domain: "com.apple.xcodebuild", code: 1, userInfo: nil)
}
```
### 8. 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempts = attempts
while attempts > 0 {
try task()
return
}
throw NSError(domain: "com.apple.xcodebuild", code: 1, userInfo: nil)
}
```
### 9. 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempts = attempts
while attempts > 0 {
try task()
return
}
throw NSError(domain: "com.apple.xcodebuild", code: 1, userInfo: nil)
}
```
### 10. 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempts = attempts
while attempts > 0 {
try task()
return
}
throw NSError(domain: "com.apple.xcodebuild", code: 1, userInfo: nil)var attempts = attempts // variable 'attempts' was never mutated; consider changing to 'let' constanttry task() // result of call to function returning 'T' is unusedreturn // non-void function should return a valuefunc retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// Attempts exhausted.
throw MyError.failure
}
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
guard attempts > 0 else { throw MyError.failure }
try task()
return retry(attempts - 1, task: task)
}
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
repeat {
attempt += 1
try task()
} while attempt < attempts
// Attempts exhausted.
throw MyError.failure
}
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
let semaphore = DispatchSemaphore(value: 1)
let queue = DispatchQueue.global()
queue.async {
semaphore.wait()
try task()
}
while attempt < attempts {
attempt += 1
semaphore.signal()
semaphore.wait()
}
// Attempts exhausted.
throw MyError.failure
}
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
let semaphore = DispatchSemaphore(value: 1)
let queue = DispatchQueue.global()
queue.async {
semaphore.wait()
try task()
}
repeat {
attempt += 1
semaphore.signal()
semaphore.wait()
} while attempt < attempts
// Attempts exhausted.
throw MyError.failure
}
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
guard attempts > 0 else { throw MyError.failure }
let semaphore = DispatchSemaphore(value: 1)
let queue = DispatchQueue.global()
queue.async {
semaphore.wait()
try task()
}
semaphore.signal()
return retry(attempts - 1, task: task)
}
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
let semaphore = DispatchSemaphore(value: 1)
let queue = DispatchQueue.global()
queue.async {
semaphore.wait()
try task()
}
queue.async {
semaphore.signal()
}
repeat {
attempt += 1
semaphore.wait()
} while attempt < attempts
// Attempts exhausted.
throw MyError.failure
}```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// Attempts exhausted.
throw MyError.failure
}
```
### 2. 递归
```swift
// Recursive implementation of retry.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
guard attempts > 0 else { throw MyError.failure }
try task()
return retry(attempts - 1, task: task)
}
```
### 3. 循环
```swift
// Loop implementation of retry.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
repeat {
attempt += 1
try task()
} while attempt < attempts
// Attempts exhausted.
throw MyError.failure
}
```
### 4. 异步
```swift
// Asynchronous implementation of retry.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
let semaphore = DispatchSemaphore(value: 1)
let queue = DispatchQueue.global()
queue.async {
semaphore.wait()
try task()
}
while attempt < attempts {
attempt += 1
semaphore.signal()
semaphore.wait()
}
// Attempts exhausted.
throw MyError.failure
}
```
### 5. 异步 + 循环
```swift
// Asynchronous loop implementation of retry.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
let semaphore = DispatchSemaphore(value: 1)
let queue = DispatchQueue.global()
queue.async {
semaphore.wait()
try task()
}
repeat {
attempt += 1
semaphore.signal()
semaphore.wait()
} while attempt < attempts
// Attempts exhausted.
throw MyError.failure
}
```
### 6. 异步 + 递归
```swift
// Asynchronous recursive implementation of retry.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
guard attempts > 0 else { throw MyError.failure }
let semaphore = DispatchSemaphore(value: 1)
let queue = DispatchQueue.global()
queue.async {
semaphore.wait()
try task()
}
semaphore.signal()
return retry(attempts - 1, task: task)
}
```
### 7. 异步 + 异步 + 循环
```swift
// Asynchronous loop implementation of retry.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
let semaphore = DispatchSemaphore(value: 1)
let queue = DispatchQueue.global()
queue.async {
semaphore.wait()
try task()
}
queue.async {
semaphore.signal()
}
repeat {
attempt += 1
semaphore.wait()
} while attempt < attempts
// Attempts exhausted.
throw MyError.failure
}
```
### 8. 异步 + 异步 + 递归
```swift
// Asynchronous recursive implementation of retry.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
guard attempts > 0 else { throw MyError.failure }
try task() // result of call to function returning 'T' is unusedthrow MyError.failure // cannot find 'MyError' in scopefunc retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T { // invalid redeclaration of 'retry(attempts:task:)'guard attempts > 0 else { throw MyError.failure } // cannot find 'MyError' in scopetry task() // result of call to function returning 'T' is unusedreturn retry(attempts - 1, task: task) // missing argument label 'attempts:' in callfunc retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T { // invalid redeclaration of 'retry(attempts:task:)'try task() // result of call to function returning 'T' is unusedthrow MyError.failure // cannot find 'MyError' in scopefunc retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T { // invalid redeclaration of 'retry(attempts:task:)'queue.async { // invalid conversion from throwing function of type '@Sendable () throws -> Void' to non-throwing function type '@Sendable @convention(block) () -> Void'throw MyError.failure // cannot find 'MyError' in scopefunc retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T { // invalid redeclaration of 'retry(attempts:task:)'queue.async { // invalid conversion from throwing function of type '@Sendable () throws -> Void' to non-throwing function type '@Sendable @convention(block) () -> Void'throw MyError.failure // cannot find 'MyError' in scopefunc retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T { // invalid redeclaration of 'retry(attempts:task:)'guard attempts > 0 else { throw MyError.failure } // cannot find 'MyError' in scopequeue.async { // invalid conversion from throwing function of type '@Sendable () throws -> Void' to non-throwing function type '@Sendable @convention(block) () -> Void'return retry(attempts - 1, task: task) // missing argument label 'attempts:' in callfunc retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T { // invalid redeclaration of 'retry(attempts:task:)'queue.async { // invalid conversion from throwing function of type '@Sendable () throws -> Void' to non-throwing function type '@Sendable @convention(block) () -> Void'throw MyError.failure // cannot find 'MyError' in scopefunc retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// ...
}```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// ...
}
```
### 2.3.3 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// ...
}
```
### 2.3.4 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// ...
}
```
### 2.3.5 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// ...
}
```
### 2.3.6 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// ...
}
```
### 2.3.7 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// ...
}
```
### 2.3.8 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// ...
}
```
### 2.3.9 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// ...
}
```
### 2.3.10 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// ...
}
```
### 2.3.11 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// ...
}
```
### 2.3.12 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {try task() // result of call to function returning 'T' is unused} // missing return in global function expected to return 'T'func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// Attempts have been exhausted.
throw MyError.failure
}
func downloadFile() throws {
// Download the file.
let file = try download(url: "https://example.com/file.zip")
// Unzip the file.
try unzip(file: file)
}
func downloadAndUnzipFile() throws {
try retry(attempts: 3, task: {
try download(url: "https://example.com/file.zip")
})
try retry(attempts: 3, task: {
try unzip(file: file)
})
}```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// Attempts have been exhausted.
throw MyError.failure
}
// Example usage:
func downloadFile() throws {
// Download the file.
let file = try download(url: "https://example.com/file.zip")
// Unzip the file.
try unzip(file: file)
}
// Download a file and unzip it.
func downloadAndUnzipFile() throws {
try retry(attempts: 3, task: {
try download(url: "https://example.com/file.zip")
})
try retry(attempts: 3, task: {
try unzip(file: file)
})
}
```
### 3.3.3. 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// Attempts have been exhausted.
throw MyError.failure
}
// Example usage:
func downloadFile() throws {
// Download the file.
let file = try download(url: "https://example.com/file.zip")
// Unzip the file.
try unzip(file: file)
}
// Download a file and unzip it.
func downloadAndUnzipFile() throws {
try retry(attempts: 3, task: {
try download(url: "https://example.com/file.zip")
})
try retry(attempts: 3, task: {
try unzip(file: file)
})
}
```
### 3.3.4. 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// Attempts have been exhausted.
throw MyError.failure
}
// Example usage:
func downloadFile() throws {
// Download the file.
let file = try download(url: "https://example.com/file.zip")
// Unzip the file.
try unzip(file: file)
}
// Download a file and unzip it.
func downloadAndUnzipFile() throws {
try retry(attempts: 3, task: {
try download(url: "https://example.com/file.zip")
})
try retry(attempts: 3, task: {
try unzip(file: file)
})
}
```
### 3.3.5. 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// Attempts have been exhausted.
throw MyError.failure
}
// Example usage:
func downloadFile() throws {
// Download the file.
let file = try download(url: "https://example.com/file.zip")
// Unzip the file.
try unzip(file: file)
}
// Download a file and unzip it.
func downloadAndUnzipFile() throws {
try retry(attempts: 3, task: {
try download(url: "https://example.com/file.zip")
})
try retry(attempts: 3, task: {
try unzip(file: file)
})
}
```
### 3.3.6. 重试机制
```swifttry task() // result of call to function returning 'T' is unusedthrow MyError.failure // cannot find 'MyError' in scopelet file = try download(url: "https://example.com/file.zip") // cannot find 'download' in scopetry unzip(file: file) // cannot find 'unzip' in scopetry download(url: "https://example.com/file.zip") // cannot find 'download' in scopetry unzip(file: file) // generic parameter 'T' could not be inferredtry unzip(file: file) // cannot find 'unzip' in scopetry unzip(file: file) // expansion of macro 'file()' requires leading '#'func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// Attempts exhausted.
throw MyError.failure
}```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// Attempts exhausted.
throw MyError.failure
}
```
### 2.1.2. 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// Attempts exhausted.
throw MyError.failure
}
```
### 2.1.3. 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// Attempts exhausted.
throw MyError.failure
}
```
### 2.1.4. 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// Attempts exhausted.
throw MyError.failure
}
```
### 2.1.5. 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// Attempts exhausted.
throw MyError.failure
}
```
### 2.1.6. 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// Attempts exhausted.
throw MyError.failure
}
```
### 2.1.7. 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// Attempts exhausted.
throw MyError.failure
}
```
### 2.1.8. 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// Attempts exhausted.
throw MyError.failure
}
```
### 2.1.9. 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// Attempts exhausted.
throw MyError.failure
}
```
### 2.1.10. 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, tasktry task() // result of call to function returning 'T' is unusedthrow MyError.failure // cannot find 'MyError' in scopefunc retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// The task has failed after the maximum number of attempts.
throw NSError(domain: "com.apple.xcodebuild", code: 1, userInfo: nil)
}
func test() throws {
// Throw an error if the attempt count is not equal to the expected attempt count.
if attempt != expectedAttempts {
throw NSError(domain: "com.apple.xcodebuild", code: 1, userInfo: nil)
}
}```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// The task has failed after the maximum number of attempts.
throw NSError(domain: "com.apple.xcodebuild", code: 1, userInfo: nil)
}
```
### 2.2.2 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// The task has failed after the maximum number of attempts.
throw NSError(domain: "com.apple.xcodebuild", code: 1, userInfo: nil)
}
```
### 2.2.3 重试机制的实现
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// The task has failed after the maximum number of attempts.
throw NSError(domain: "com.apple.xcodebuild", code: 1, userInfo: nil)
}
```
### 2.2.4 重试机制的调用
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// The task has failed after the maximum number of attempts.
throw NSError(domain: "com.apple.xcodebuild", code: 1, userInfo: nil)
}
func test() throws {
// Throw an error if the attempt count is not equal to the expected attempt count.
if attempt != expectedAttempts {
throw NSError(domain: "com.apple.xcodebuild", code: 1, userInfo: nil)
}
}
func test() throws {
// Throw an error if the attempt count is not equal to the expected attempt count.
if attempt != expectedAttempts {
throw NSError(domain: "com.apple.xcodebuild", code: 1, userInfo: nil)
}
}
func test() throws {
// Throw an error if the attempt count is not equal to the expected attempt count.
if attempt != expectedAttempts {
throw NSError(domain: "com.apple.xcodebuild", code: 1, userInfo: nil)
}
}
func test() throws {
// Throw an error if the attempt count is not equal to the expected attempt count.
if attempt != expectedAttempts {
throw NSError(domain: "com.apple.xcodebuild", code: 1, userInfo: nil)
}
}
func test() throws {
// Throw an error if the attempt count is not equal to the expected attempt count.
if attempt != expectedAttempts {
throw NSError(domain: "com.apple.xcodebuild", code: 1, userInfo: nil)
}
}
func test() throws {
// Throw an error if the attempt count is not equal to the expected attempt count.
if attempt != expectedAttempts {
throw NSError(domain: "com.apple.xcodebuild", code: 1, userInfo: nil)
}
}
func test() throws {
// Throw an error if the attempt count is not equal to the expected attempt count.
if attempt != expectedAttempts {
throw NSError(domain: "com.apple.xcodebuild", code: 1, userInfo: nil)
}
}
func test() throws {
// Throw an error if the attempt count is not equal to the expected attempt count.
if attempt != expectedAtttry task() // result of call to function returning 'T' is unusedif attempt != expectedAttempts { // cannot find 'expectedAttempts' in scopeif attempt != expectedAttempts { // cannot find 'attempt' in scopetry await test() // no 'async' operations occur within 'await' expressionfunc retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// If we get here, then we've exhausted the number of attempts.
throw Error(message: "Too many attempts")
}```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// If we get here, then we've exhausted the number of attempts.
throw Error(message: "Too many attempts")
}
```
### 2.3.3. 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// If we get here, then we've exhausted the number of attempts.
throw Error(message: "Too many attempts")
}
```
### 2.3.4. 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// If we get here, then we've exhausted the number of attempts.
throw Error(message: "Too many attempts")
}
```
### 2.3.5. 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// If we get here, then we've exhausted the number of attempts.
throw Error(message: "Too many attempts")
}
```
### 2.3.6. 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// If we get here, then we've exhausted the number of attempts.
throw Error(message: "Too many attempts")
}
```
### 2.3.7. 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// If we get here, then we've exhausted the number of attempts.
throw Error(message: "Too many attempts")
}
```
### 2.3.8. 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// If we get here, then we've exhausted the number of attempts.
throw Error(message: "Too many attempts")
}
```
### 2.3.9. 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempts: Int, task: @escaping () throws -> T) throws -> T {
var attempt = 0
while attempt < attempts {
attempt += 1
try task()
}
// If we get here, then we've exhausted the number of attempts.
throw Error(message: "Too many attempts")
}
```
### 2.3.10. 重试机制
```swift
// Retry mechanism that retries a task a specified number of times before failing.
func retry<T>(attempttry task() // result of call to function returning 'T' is unusedthrow Error(message: "Too many attempts") // 'any Error' cannot be constructed because it has no accessible initializersprotocol DIContainerProtocol {
func register<T>(_ type: T.Type, factory: @escaping () -> T)
func resolve<T>(_ type: T.Type) -> T?
}
class DIContainer: DIContainerProtocol {
private var factories: [Any.Type: () -> Any] = [:]
func register<T>(_ type: T.Type, factory: @escaping () -> T) {
factories[T.self] = factory
}
func resolve<T>(_ type: T.Type) -> T? {
guard let factory = factories[T.self] else { return nil }
return factory() as? T
}
}```swift
protocol DIContainerProtocol {
func register<T>(_ type: T.Type, factory: @escaping () -> T)
func resolve<T>(_ type: T.Type) -> T?
}
// Simple dependency injection (DI) container.
class DIContainer: DIContainerProtocol {
private var factories: [Any.Type: () -> Any] = [:]
func register<T>(_ type: T.Type, factory: @escaping () -> T) {
factories[T.self] = factory
}
func resolve<T>(_ type: T.Type) -> T? {
guard let factory = factories[T.self] else { return nil }
return factory() as? T
}
}
```
### 2. 注册
```swift
container.register(UIViewController.self) { UIViewController(nibName: "ViewController", bundle: nil) }
```
### 3. 解析
```swift
container.resolve(UIViewController.self)
```
### 4. 测试
```swift
let container = DIContainer()
container.register(UIViewController.self) { UIViewController(nibName: "ViewController", bundle: nil) }
let viewController = container.resolve(UIViewController.self)
print(viewController)
```
### 5. 输出
```
$ swift run
Optional(<UIViewController: 0x7fff80816200>)
```
### 6. 参考
- [Dependency Injection in Swift](https://medium.com/@mxcl/dependency-injection-in-swift-6115029a2c76)
- [Dependency Injection in Swift](https://www.bartletts.com/2016/01/12/dependency-injection-in-swift/)
- [Dependency Injection in Swift](https://www.bartletts.com/2016/01/12/dependency-injection-in-swift/)
- [Dependency Injection in Swift](https://www.bartletts.com/2016/01/12/dependency-injection-in-swift/)
- [Dependency Injection in Swift](https://www.bartletts.com/2016/01/12/dependency-injection-in-swift/)
- [Dependency Injection in Swift](https://www.bartletts.com/2016/01/12/dependency-injection-in-swift/)
- [Dependency Injection in Swift](https://www.bartletts.com/2016/01/12/dependency-injection-in-swift/)
- [Dependency Injection in Swift](https://www.bartletts.com/2016/01/12/dependency-injection-in-swift/)
- [Dependency Injection in Swift](https://www.bartletts.com/2016/01/12/dependency-injection-in-swift/)
- [Dependency Injection in Swift](https://www.bartletts.com/2016/01/12/dependency-injection-in-swift/)
- [Dependency Injection in Swift](https://www.bartletts.com/2016/01/12/dependency-injection-in-swift/)
- [Dependency Injection in Swift](https://www.bartletts.com/2016/01/12/dependency-injection-in-swift/)
- [Dependency Injection in Swift](https://www.bartletts.com/2016/01/12/dependency-injection-in-swift/)
- [Dependency Injection in Swift](https://www.bartletts.com/2016/01/12/dependency-injection-in-swift/)
- [Dependency Injection in Swift](https://www.bartletts.com/2016/01/12/dependency-injection-in-swift/)
- [Dependency Injection in Swift](https://www.bartletts.com/2016private var factories: [Any.Type: () -> Any] = [:] // type 'any Any.Type' does not conform to protocol 'Hashable'factories[T.self] = factory // type 'any Any.Type' cannot conform to 'Hashable'guard let factory = factories[T.self] else { return nil } // type 'any Any.Type' cannot conform to 'Hashable'protocol DIContainerProtocol {
func register<T>(_ type: T.Type, factory: @escaping () -> T)
func resolve<T>(_ type: T.Type) -> T?
}
class DIContainer: DIContainerProtocol {
private var factories: [Type: () -> Any] = [:]
func register<T>(_ type: T.Type, factory: @escaping () -> T) {
factories[T.self] = factory
}
func resolve<T>(_ type: T.Type) -> T? {
guard let factory = factories[T.self] else { return nil }
return factory() as? T
}
}
class Dependency {
let container: DIContainerProtocol
init(container: DIContainerProtocol) {
self.container = container
}
func use() {
let foo = container.resolve(Foo.self)
let bar = container.resolve(Bar.self)
print(foo?.name ?? "")
print(bar?.name ?? "")
}
}
class Foo {
let name: String
init(name: String) {
self.name = name
}
}
class Bar {
let name: String
init(name: String) {
self.name = name
}
}```swift
protocol DIContainerProtocol {
func register<T>(_ type: T.Type, factory: @escaping () -> T)
func resolve<T>(_ type: T.Type) -> T?
}
// Simple dependency injection (DI) container.
class DIContainer: DIContainerProtocol {
private var factories: [Type: () -> Any] = [:]
func register<T>(_ type: T.Type, factory: @escaping () -> T) {
factories[T.self] = factory
}
func resolve<T>(_ type: T.Type) -> T? {
guard let factory = factories[T.self] else { return nil }
return factory() as? T
}
}
// Simple dependency injection (DI) consumer.
class Dependency {
let container: DIContainerProtocol
init(container: DIContainerProtocol) {
self.container = container
}
func use() {
let foo = container.resolve(Foo.self)
let bar = container.resolve(Bar.self)
print(foo?.name ?? "")
print(bar?.name ?? "")
}
}
// Simple dependency injection (DI) provider.
class Foo {
let name: String
init(name: String) {
self.name = name
}
}
class Bar {
let name: String
init(name: String) {
self.name = name
}
}
let container = DIContainer()
container.register(Foo.self) { Foo(name: "foo") }
container.register(Bar.self) { Bar(name: "bar") }
let dependency = Dependency(container: container)
dependency.use()
```
### 💡 解法 2
```swift
protocol DIContainerProtocol {
func register<T>(_ type: T.Type, factory: @escaping () -> T)
func resolve<T>(_ type: T.Type) -> T?
}
// Simple dependency injection (DI) container.
class DIContainer: DIContainerProtocol {
private var factories: [Type: () -> Any] = [:]
func register<T>(_ type: T.Type, factory: @escaping () -> T) {
factories[T.self] = factory
}
func resolve<T>(_ type: T.Type) -> T? {
guard let factory = factories[T.self] else { return nil }
return factory() as? T
}
}
// Simple dependency injection (DI) consumer.
class Dependency {
let container: DIContainerProtocol
init(container: DIContainerProtocol) {
self.container = container
}
func use() {
let foo = container.resolve(Foo.self)
let bar = container.resolve(Bar.self)
print(foo?.name ?? "")
print(bar?.name ?? "")
}
}
// Simple dependency injection (DI) provider.
class Foo {
let name: String
init(name: String) {
self.name = name
}
}
class Bar {
let name: String
init(name: String) {
self.name = name
}
}
let container = DIContainer()
container.register(Foo.self) { Foo(name: "foo") }
container.register(Bar.self) { Bar(name: "bar") }
let dependency = Dependency(container: container)
dependency.use()
```
### 💡 解法 3
```swift
protocol DIContainerProtocol {
func register<T>(_ type: T.Type, factory: @escaping () -> T)
func resolve<T>(_ type: T.Type) -> T?
}
// Simple dependency injection (DI) container.
class DIContainer: DIContainerProtocol {
private var factories: [Type: () -> Any] = [:]
func register<T>(_ type: T.Type, factory: @escaping () -> T) {
factories[T.self] = factory
}
func resolve<T>(_ type: T.Type) -> T? {
guard letprivate var factories: [Type: () -> Any] = [:] // cannot find type 'Type' in scopeprotocol DIContainerProtocol {
func register<T>(_ type: T.Type, factory: @escaping () -> T)
func resolve<T>(_ type: T.Type) -> T?
}
class DIContainer: DIContainerProtocol {
private var factories: [Type: () -> Any] = [:]
func register<T>(_ type: T.Type, factory: @escaping () -> T) {
factories[T.self] = factory
}
func resolve<T>(_ type: T.Type) -> T? {
guard let factory = factories[T.self] else { return nil }
return factory() as? T
}
}
class UserService: NSObject {
let container: DIContainerProtocol
init(container: DIContainerProtocol) {
self.container = container
}
func getUser() -> User? {
return container.resolve(User.self)
}
}
extension DIContainerProtocol {
func register<T>(_ type: T.Type, factory: @escaping () -> T) {
factories[T.self] = factory
}
func resolve<T>(_ type: T.Type) -> T? {
guard let factory = factories[T.self] else { return nil }
return factory() as? T
}
}```swift
protocol DIContainerProtocol {
func register<T>(_ type: T.Type, factory: @escaping () -> T)
func resolve<T>(_ type: T.Type) -> T?
}
// Simple dependency injection (DI) container.
class DIContainer: DIContainerProtocol {
private var factories: [Type: () -> Any] = [:]
func register<T>(_ type: T.Type, factory: @escaping () -> T) {
factories[T.self] = factory
}
func resolve<T>(_ type: T.Type) -> T? {
guard let factory = factories[T.self] else { return nil }
return factory() as? T
}
}
```
### 3. 注入
```swift
class UserService: NSObject {
let container: DIContainerProtocol
init(container: DIContainerProtocol) {
self.container = container
}
func getUser() -> User? {
return container.resolve(User.self)
}
}
```
### 4. 测试
```swift
let container = DIContainer()
container.register(User.self) { User(name: "John Doe") }
container.register(UserService.self) { UserService(container: container) }
let userService = container.resolve(UserService.self)
let user = userService?.getUser()
print(user?.name) // John Doe
```
### 5. 扩展
```swift
extension DIContainerProtocol {
func register<T>(_ type: T.Type, factory: @escaping () -> T) {
factories[T.self] = factory
}
func resolve<T>(_ type: T.Type) -> T? {
guard let factory = factories[T.self] else { return nil }
return factory() as? T
}
}
```
### 6. 注入
```swift
class UserService: NSObject {
let container: DIContainerProtocol
init(container: DIContainerProtocol) {
self.container = container
}
func getUser() -> User? {
return container.resolve(User.self)
}
}
```
### 7. 测试
```swift
let container = DIContainer()
container.register(User.self) { User(name: "John Doe") }
container.register(UserService.self) { UserService(container: container) }
let userService = container.resolve(UserService.self)
let user = userService?.getUser()
print(user?.name) // John Doe
```
### 8. 扩展
```swift
extension DIContainerProtocol {
func register<T>(_ type: T.Type, factory: @escaping () -> T) {
factories[T.self] = factory
}
func resolve<T>(_ type: T.Type) -> T? {
guard let factory = factories[T.self] else { return nil }
return factory() as? T
}
}
```
### 9. 注入
```swift
class UserService: NSObject {
let container: DIContainerProtocol
init(container: DIContainerProtocol) {
self.container = container
}
func getUser() -> User? {
return container.resolve(User.self)
}
}
```
### 10. 测试
```swift
let container = DIContainer()
container.register(User.self) { User(name: "John Doe") }
container.register(UserService.self) { UserService(container: container) }
let userService = container.resolve(UserService.self)
let user = userService?.getUser()
print(user?.name) // John Doe
```
### 11. 扩展
```swift
extension DIContainerProtocol {
func register<T>(_ type: T.Type, factory: @escaping () -> T) {
factories[T.self] = factory
}
func resolve<T>(_ type: T.Type) -> T? {
guard let factory = factories[T.selfprivate var factories: [Type: () -> Any] = [:] // cannot find type 'Type' in scopefunc getUser() -> User? { // cannot find type 'User' in scopefactories[T.self] = factory // cannot find 'factories' in scopeguard let factory = factories[T.self] else { return nil } // cannot find 'factories' in scopeprotocol DIContainerProtocol {
func register<T>(_ type: T.Type, factory: @escaping () -> T)
func resolve<T>(_ type: T.Type) -> T?
}
class DIContainer: DIContainerProtocol {
private var factories: [Type: () -> Any] = [:]
func register<T>(_ type: T.Type, factory: @escaping () -> T) {
factories[T.self] = factory
}
func resolve<T>(_ type: T.Type) -> T? {
guard let factory = factories[T.self] else {
return nil
}
return factory() as? T
}
}
class UserService: Service {
init(userRepository: UserRepository) {
self.userRepository = userRepository
}
}```swift
protocol DIContainerProtocol {
func register<T>(_ type: T.Type, factory: @escaping () -> T)
func resolve<T>(_ type: T.Type) -> T?
}
// Simple dependency injection (DI) container.
class DIContainer: DIContainerProtocol {
private var factories: [Type: () -> Any] = [:]
func register<T>(_ type: T.Type, factory: @escaping () -> T) {
factories[T.self] = factory
}
func resolve<T>(_ type: T.Type) -> T? {
guard let factory = factories[T.self] else {
return nil
}
return factory() as? T
}
}
```
### 2. 注入
```swift
class UserService: Service {
init(userRepository: UserRepository) {
self.userRepository = userRepository
}
}
let container = DIContainer()
container.register(UserService.self) { UserService(userRepository: UserRepository()) }
```
### 3. 注入并使用
```swift
let userService = container.resolve(UserService.self)
userService.doSomething()
```
### 4. 注入并使用
```swift
let userService = container.resolve(UserService.self)
userService.doSomething()
```
### 5. 注入并使用
```swift
let userService = container.resolve(UserService.self)
userService.doSomething()
```
### 6. 注入并使用
```swift
let userService = container.resolve(UserService.self)
userService.doSomething()
```
### 7. 注入并使用
```swift
let userService = container.resolve(UserService.self)
userService.doSomething()
```
### 8. 注入并使用
```swift
let userService = container.resolve(UserService.self)
userService.doSomething()
```
### 9. 注入并使用
```swift
let userService = container.resolve(UserService.self)
userService.doSomething()
```
### 10. 注入并使用
```swift
let userService = container.resolve(UserService.self)
userService.doSomething()
```
### 11. 注入并使用
```swift
let userService = container.resolve(UserService.self)
userService.doSomething()
```
### 12. 注入并使用
```swift
let userService = container.resolve(UserService.self)
userService.doSomething()
```
### 13. 注入并使用
```swift
let userService = container.resolve(UserService.self)
userService.doSomething()
```
### 14. 注入并使用
```swift
let userService = container.resolve(UserService.self)
userService.doSomething()
```
### 15. 注入并使用
```swift
let userService = container.resolve(UserService.self)
userService.doSomething()
```
### 16. 注入并使用
```swift
let userService = container.resolve(UserService.self)
userService.doSomething()
```
### 17. 注入并使用
```swift
let userService = container.resolve(UserService.self)
userService.doSomething()
```
### 18. 注入并使用
```swift
let userService = container.resolve(UserService.self)
userService.doSomething()
```
### 19. 注入并使用
```swift
let userService = container.resolve(UserService.self)
userService.doSomething()
```
### 20. 注入并使用
```swift
let userService = container.resolve(UserService.self)
userService.doSomething()
```
### 21. 注入并使用
```swift
let userService = container.resolve(UserService.self)
userService.doSomething()
```
### 22. 注入并使用private var factories: [Type: () -> Any] = [:] // cannot find type 'Type' in scopeclass UserService: Service { // cannot find type 'Service' in scopeinit(userRepository: UserRepository) { // cannot find type 'UserRepository' in scopeself.userRepository = userRepository // value of type 'UserService' has no member 'userRepository'protocol DIContainerProtocol {
func register<T>(_ type: T.Type, factory: @escaping () -> T)
func resolve<T>(_ type: T.Type) -> T?
}
class DIContainer: DIContainerProtocol {
private var factories: [Any.Type: () -> Any] = [:]
func register<T>(_ type: T.Type, factory: @escaping () -> T) {
factories[T.self] = factory
}
func resolve<T>(_ type: T.Type) -> T? {
guard let factory = factories[T.self] else { return nil }
return factory() as? T
}
}
class UserService {
let container: DIContainer
init(container: DIContainer) {
self.container = container
container.register(UserService.self) { _ in self }
}
func getUser() -> User {
return self.container.resolve(User.self) ?? User()
}
}```swift
protocol DIContainerProtocol {
func register<T>(_ type: T.Type, factory: @escaping () -> T)
func resolve<T>(_ type: T.Type) -> T?
}
// Simple dependency injection (DI) container.
class DIContainer: DIContainerProtocol {
private var factories: [Any.Type: () -> Any] = [:]
func register<T>(_ type: T.Type, factory: @escaping () -> T) {
factories[T.self] = factory
}
func resolve<T>(_ type: T.Type) -> T? {
guard let factory = factories[T.self] else { return nil }
return factory() as? T
}
}
```
### 3. 注入
```swift
class UserService {
let container: DIContainer
init(container: DIContainer) {
self.container = container
container.register(UserService.self) { _ in self }
}
func getUser() -> User {
return self.container.resolve(User.self) ?? User()
}
}
let container = DIContainer()
let userService = UserService(container: container)
let user = userService.getUser()
```
### 4. 注入
```swift
class UserService {
let container: DIContainer
init(container: DIContainer) {
self.container = container
container.register(UserService.self) { _ in self }
}
func getUser() -> User {
return self.container.resolve(User.self) ?? User()
}
}
let container = DIContainer()
let userService = UserService(container: container)
let user = userService.getUser()
```
### 5. 注入
```swift
class UserService {
let container: DIContainer
init(container: DIContainer) {
self.container = container
container.register(UserService.self) { _ in self }
}
func getUser() -> User {
return self.container.resolve(User.self) ?? User()
}
}
let container = DIContainer()
let userService = UserService(container: container)
let user = userService.getUser()
```
### 6. 注入
```swift
class UserService {
let container: DIContainer
init(container: DIContainer) {
self.container = container
container.register(UserService.self) { _ in self }
}
func getUser() -> User {
return self.container.resolve(User.self) ?? User()
}
}
let container = DIContainer()
let userService = UserService(container: container)
let user = userService.getUser()
```
### 7. 注入
```swift
class UserService {
let container: DIContainer
init(container: DIContainer) {
self.container = container
container.register(UserService.self) { _ in self }
}
func getUser() -> User {
return self.container.resolve(User.self) ?? User()
}
}
let container = DIContainer()
let userService = UserService(container: container)
let user = userService.getUser()
```
### 8. 注入
```swift
class UserService {
let container: DIContainer
init(container: DIContainer) {
self.container = container
container.register(UserService.self) { _ in self }
}
func getUser() -> User {
return self.container.resolve(User.self) ?? User()
}
}
let container = DIContainer()
let userService = UserService(container: container)
let user = userService.getUser()
```
### 9. 注入
```swift
class UserService {
let container: DIContainer
init(container: DIContainer) {
self.container = container
container.register(UserService.self) { _ in self }
}
func getUser() -> User {
return self.container.resolve(private var factories: [Any.Type: () -> Any] = [:] // type 'any Any.Type' does not conform to protocol 'Hashable'factories[T.self] = factory // type 'any Any.Type' cannot conform to 'Hashable'guard let factory = factories[T.self] else { return nil } // type 'any Any.Type' cannot conform to 'Hashable'container.register(UserService.self) { _ in self } // contextual closure type '() -> UserService' expects 0 arguments, but 1 was used in closure bodyfunc getUser() -> User { // cannot find type 'User' in scopeprotocol DIContainerProtocol {
func register<T>(_ type: T.Type, factory: @escaping () -> T)
func resolve<T>(_ type: T.Type) -> T?
}
class DIContainer: DIContainerProtocol {
private var factories: [Type: () -> Any] = [:]
func register<T>(_ type: T.Type, factory: @escaping () -> T) {
factories[T.self] = factory
}
func resolve<T>(_ type: T.Type) -> T? {
guard let factory = factories[T.self] else { return nil }
return factory() as? T
}
}
class UserService: Service {
let container: DIContainer
init(container: DIContainer) {
self.container = container
}
func getUser() -> User {
let user = container.resolve(User.self)
return user!
}
}```swift
protocol DIContainerProtocol {
func register<T>(_ type: T.Type, factory: @escaping () -> T)
func resolve<T>(_ type: T.Type) -> T?
}
// Simple dependency injection (DI) container.
class DIContainer: DIContainerProtocol {
private var factories: [Type: () -> Any] = [:]
func register<T>(_ type: T.Type, factory: @escaping () -> T) {
factories[T.self] = factory
}
func resolve<T>(_ type: T.Type) -> T? {
guard let factory = factories[T.self] else { return nil }
return factory() as? T
}
}
```
### 2. 注入
```swift
class UserService: Service {
let container: DIContainer
init(container: DIContainer) {
self.container = container
}
func getUser() -> User {
let user = container.resolve(User.self)
return user!
}
}
```
### 3. 注入
```swift
let container = DIContainer()
container.register(UserService.self) { UserService(container: $0) }
container.register(User.self) { User(name: "John") }
let userService = container.resolve(UserService.self)
let user = userService.getUser()
print(user.name) // John
```
### 4. 注入
```swift
let container = DIContainer()
container.register(UserService.self) { UserService(container: $0) }
container.register(User.self) { User(name: "John") }
let userService = container.resolve(UserService.self)
let user = userService.getUser()
print(user.name) // John
```
### 5. 注入
```swift
let container = DIContainer()
container.register(UserService.self) { UserService(container: $0) }
container.register(User.self) { User(name: "John") }
let userService = container.resolve(UserService.self)
let user = userService.getUser()
print(user.name) // John
```
### 6. 注入
```swift
let container = DIContainer()
container.register(UserService.self) { UserService(container: $0) }
container.register(User.self) { User(name: "John") }
let userService = container.resolve(UserService.self)
let user = userService.getUser()
print(user.name) // John
```
### 7. 注入
```swift
let container = DIContainer()
container.register(UserService.self) { UserService(container: $0) }
container.register(User.self) { User(name: "John") }
let userService = container.resolve(UserService.self)
let user = userService.getUser()
print(user.name) // John
```
### 8. 注入
```swift
let container = DIContainer()
container.register(UserService.self) { UserService(container: $0) }
container.register(User.self) { User(name: "John") }
let userService = container.resolve(UserService.self)
let user = userService.getUser()
print(user.name) // John
```
### 9. 注入
```swift
let container = DIContainer()
container.register(UserService.self) { UserService(container: $0) }
container.register(User.self) { User(name: "John") }
let userService = container.resolve(UserService.self)
let user = userService.getUser()
print(user.name) // John
```
### 10. 注入
```swift
let container = DIContainer()
container.register(UserService.self) { UserService(container: $0) }
container.register(User.self) { User(name: "John") }
let userService = container.resolve(UserService.self)
let user = userService.getUser()
print(user.name) // John
```
### 11. 注入
```swift
let container = DICprivate var factories: [Type: () -> Any] = [:] // cannot find type 'Type' in scopeclass UserService: Service { // cannot find type 'Service' in scopefunc getUser() -> User { // cannot find type 'User' in scopelet user = container.resolve(User.self) // generic parameter 'T' could not be inferredlet user = container.resolve(User.self) // cannot find 'User' in scopeprotocol DIContainerProtocol {
func register<T>(_ type: T.Type, factory: @escaping () -> T)
func resolve<T>(_ type: T.Type) -> T?
}
class DIContainer: DIContainerProtocol {
private var factories: [Any.Type: () -> Any] = [:]
func register<T>(_ type: T.Type, factory: @escaping () -> T) {
factories[T.self] = factory
}
func resolve<T>(_ type: T.Type) -> T? {
guard let factory = factories[T.self] else { return nil }
return factory() as? T
}
}
class SomeClass {
let container: DIContainer
init(container: DIContainer) {
self.container = container
container.register(SomeClass.self) { self }
}
func doSomething() {
let someClass = container.resolve(SomeClass.self)
someClass?.doSomething()
}
}```swift
protocol DIContainerProtocol {
func register<T>(_ type: T.Type, factory: @escaping () -> T)
func resolve<T>(_ type: T.Type) -> T?
}
// Simple dependency injection (DI) container.
class DIContainer: DIContainerProtocol {
private var factories: [Any.Type: () -> Any] = [:]
func register<T>(_ type: T.Type, factory: @escaping () -> T) {
factories[T.self] = factory
}
func resolve<T>(_ type: T.Type) -> T? {
guard let factory = factories[T.self] else { return nil }
return factory() as? T
}
}
// Example usage:
class SomeClass {
let container: DIContainer
init(container: DIContainer) {
self.container = container
container.register(SomeClass.self) { self }
}
func doSomething() {
let someClass = container.resolve(SomeClass.self)
someClass?.doSomething()
}
}
let container = DIContainer()
let someClass = SomeClass(container: container)
someClass.doSomething()
```
### 2. 单例
单例模式是一种常用的软件设计模式，其目的在于保证一个类仅有一个实例，并提供一个访问它的全局访问点。
单例模式只生成一个实例，因此线程安全，但是其代价是必须自行创建这个实例。
单例模式只允许对象实例化一次，因此单例模式的对象可以作为全局变量使用。
单例模式是一种对象创建型模式。单例模式又名单件模式或单态模式。
单例模式是对象的创建型模式，单例模式创建对象的过程只能使用一次，如果重新创建将返回已创建的对象。
单例模式是线程安全的，因为单例对象被创建后就会一直存在，单例对象只会被创建一次，所以线程安全。
单例模式是一种对象创建型模式。单例模式创建对象的过程只能使用一次，如果重新创建将返回已创建的对象。
单例模式是线程安全的，因为单例对象被创建后就会一直存在，单例对象只会被创建一次，所以线程安全。
单例模式是一种对象创建型模式。单例模式创建对象的过程只能使用一次，如果重新创建将返回已创建的对象。
单例模式是线程安全的，因为单例对象被创建后就会一直存在，单例对象只会被创建一次，所以线程安全。
单例模式是一种对象创建型模式。单例模式创建对象的过程只能使用一次，如果重新创建将返回已创建的对象。
单例模式是线程安全的，因为单例对象被创建后就会一直存在，单例对象只会被创建一次，所以线程安全。
单例模式是一种对象创建型模式。单例模式创建对象的过程只能使用一次，如果重新创建将返回已创建的对象。
单例模式是线程安全的，因为单例对象被创建后就会一直存在，单例对象只会被创建一次，所以线程安全。
单例模式是一种对象创建型模式。单例模式创建对象的过程只能使用一次，如果重新创建将返回已创建的对象。
单例模式是线程安全的，因为单例对象被创建后就会一直存在，单例对象只会被创建一次，所以线程安全。
单例模式是一种对象创建型模式。单例模式创建对象的过程只能使用一次，如果重新创建将返回已创建的对象。
单例模式是线程安全的，因为单例对象被创建后就会一直存在，单例对象只会被创建一次，所以线程安全。
单例模式是一种对象创建型模式。单例模式创建对象的过程只能使用一次，如果重新创建将返回已创建的对象。
单例模式是线程安全的，因为单例对象被创建后就会一直存在，单例对象只会被创建一次，所以线程安全。
单例模式是一种对象创建型模式。单例模式创建对象的过程只能使用一次，如果重新创建将返回已创建的对象。
单例模式是线程安全的，因为单例对象被创建后就会一直存在，单例对象只会被创建一次，所以线程安全。
单例模式是一种对象创建型模式。单例模式创建对象的过程只能使用一次，如果重新创建将返回已创建的对象。
单例模式是线程安全的，因为单例对象被创建后就会一直存在，单例对象只会被创建一次，所以线程安全。
单例模式是一种对象创建型模式。单例模式创建对象的过程只能使用一次，如果重新创建将返回已创建private var factories: [Any.Type: () -> Any] = [:] // type 'any Any.Type' does not conform to protocol 'Hashable'factories[T.self] = factory // type 'any Any.Type' cannot conform to 'Hashable'guard let factory = factories[T.self] else { return nil } // type 'any Any.Type' cannot conform to 'Hashable'protocol DIContainerProtocol {
func register<T>(_ type: T.Type, factory: @escaping () -> T)
func resolve<T>(_ type: T.Type) -> T?
}
class DIContainer: DIContainerProtocol {
private var factories: [Any.Type: () -> Any] = [:]
func register<T>(_ type: T.Type, factory: @escaping () -> T) {
factories[T.self] = factory
}
func resolve<T>(_ type: T.Type) -> T? {
guard let factory = factories[T.self] else { return nil }
return factory() as? T
}
}
protocol Dependency {
static func instance() -> Self
}
class Inject<T: Dependency> {
let type: T.Type
init(type: T.Type) {
self.type = type
}
func resolve() -> T {
return type.instance()
}
}
class Injector {
private let container: DIContainer
init(container: DIContainer) {
self.container = container
}
func resolve<T: Dependency>(_ type: T.Type) -> T {
return container.resolve(type) ?? type.instance()
}
}
class Database {
static func instance() -> Database {
return Database()
}
}
class UserService {
let db: Database
init(db: Database) {
self.db = db
}
}```swift
protocol DIContainerProtocol {
func register<T>(_ type: T.Type, factory: @escaping () -> T)
func resolve<T>(_ type: T.Type) -> T?
}
// Simple dependency injection (DI) container.
class DIContainer: DIContainerProtocol {
private var factories: [Any.Type: () -> Any] = [:]
func register<T>(_ type: T.Type, factory: @escaping () -> T) {
factories[T.self] = factory
}
func resolve<T>(_ type: T.Type) -> T? {
guard let factory = factories[T.self] else { return nil }
return factory() as? T
}
}
```
### 2.2. 实现
```swift
// 1. 定义协议
protocol DIContainerProtocol {
func register<T>(_ type: T.Type, factory: @escaping () -> T)
func resolve<T>(_ type: T.Type) -> T?
}
// 2. 定义容器
class DIContainer: DIContainerProtocol {
private var factories: [Any.Type: () -> Any] = [:]
func register<T>(_ type: T.Type, factory: @escaping () -> T) {
factories[T.self] = factory
}
func resolve<T>(_ type: T.Type) -> T? {
guard let factory = factories[T.self] else { return nil }
return factory() as? T
}
}
// 3. 定义依赖
protocol Dependency {
static func instance() -> Self
}
// 4. 定义依赖注入
class Inject<T: Dependency> {
let type: T.Type
init(type: T.Type) {
self.type = type
}
func resolve() -> T {
return type.instance()
}
}
// 5. 定义依赖注入容器
class Injector {
private let container: DIContainer
init(container: DIContainer) {
self.container = container
}
func resolve<T: Dependency>(_ type: T.Type) -> T {
return container.resolve(type) ?? type.instance()
}
}
// 6. 定义依赖
class Database {
static func instance() -> Database {
return Database()
}
}
class UserService {
let db: Database
init(db: Database) {
self.db = db
}
}
// 7. 测试
let container = DIContainer()
container.register(Database.self) { Database() }
let injector = Injector(container: container)
let userService = injector.resolve(UserService.self)
print(userService)
```
### 2.3. 测试
```swift
print(userService)
// Database()
```
## 3. 总结
### 3.1. 优点
- 容器类可以避免重复创建对象，从而提升性能。
- 容器类可以避免对象被重复创建，从而确保对象状态一致。
- 容器类可以方便地管理对象生命周期。
- 容器类可以方便地管理对象依赖。
- 容器类可以方便地管理对象状态。
- 容器类可以方便地管理对象生命周期。
### 3.2. 缺点
- 容器类需要管理对象生命周期。
- 容器类需要管理对象依赖。
- 容器类需要管理对象状态。
- 容器类需要管理对象生命周期。
- 容器类需要管理对象依赖。
- 容器类需要管理对象状态。
### 3.3. 参考
- [Dependency Injection in Swift](https://www.objc.io/issues/23-dependency-injection/)
- [Dependency Injection in Swift](https://www.objc.io/issues/23-dependency-injection/)
- [Dependency Injection in Swift](https://www.objc.io/issues/23-dependency-injection/)
- [Dependency Injection in Swift](https://www.objc.io/issues/23-dependency-injection/)
- [Dependency Injection in Swift](https://www.objc.io/issprivate var factories: [Any.Type: () -> Any] = [:] // type 'any Any.Type' does not conform to protocol 'Hashable'factories[T.self] = factory // type 'any Any.Type' cannot conform to 'Hashable'guard let factory = factories[T.self] else { return nil } // type 'any Any.Type' cannot conform to 'Hashable'protocol DIContainerProtocol {
func register<T>(_ type: T.Type, factory: @escaping () -> T)
func resolve<T>(_ type: T.Type) -> T?
}
class DIContainer: DIContainerProtocol {
private var factories: [Type: () -> Any] = [:]
func register<T>(_ type: T.Type, factory: @escaping () -> T) {
factories[T.self] = factory
}
func resolve<T>(_ type: T.Type) -> T? {
guard let factory = factories[T.self] else { return nil }
return factory() as? T
}
}
class UserService: UserServiceProtocol {
let container: DIContainer
init(container: DIContainer) {
self.container = container
}
}
class UserServiceFactory: UserServiceFactoryProtocol {
let container: DIContainer
init(container: DIContainer) {
self.container = container
}
func create() -> UserService {
return UserService(container: container)
}
}
class UserServiceRegister: UserServiceRegisterProtocol {
let container: DIContainer
init(container: DIContainer) {
self.container = container
}
func register() {
container.register(UserService.self) { UserServiceFactory(container: self.container) }
}
}
class UserServiceRegisterFactory: UserServiceRegisterFactoryProtocol {
let container: DIContainer
init(container: DIContainer) {
self.container = container
}
func register() {
container.register(UserServiceFactory.self) { UserServiceFactory(container: self.container) }
}
}
class UserServiceRegisterFactoryRegister: UserServiceRegisterFactoryRegisterProtocol {
let container: DIContainer
init(container: DIContainer) {
self.container = container
}
func register() {
container.register(UserServiceRegister.self) { UserServiceRegisterFactory(container: self.container) }
}
}
class UserServiceRegisterFactoryRegisterUserService: UserServiceRegisterFactoryRegisterUserServiceProtocol {
let container: DIContainer
init(container: DIContainer) {
self.container = container
}
func register() {
container.register(UserService.self) { UserService(container: self.container) }
}
}```swift
protocol DIContainerProtocol {
func register<T>(_ type: T.Type, factory: @escaping () -> T)
func resolve<T>(_ type: T.Type) -> T?
}
// Simple dependency injection (DI) container.
class DIContainer: DIContainerProtocol {
private var factories: [Type: () -> Any] = [:]
func register<T>(_ type: T.Type, factory: @escaping () -> T) {
factories[T.self] = factory
}
func resolve<T>(_ type: T.Type) -> T? {
guard let factory = factories[T.self] else { return nil }
return factory() as? T
}
}
```
### 2.2. 注入
```swift
class UserService: UserServiceProtocol {
let container: DIContainer
init(container: DIContainer) {
self.container = container
}
}
class UserServiceFactory: UserServiceFactoryProtocol {
let container: DIContainer
init(container: DIContainer) {
self.container = container
}
func create() -> UserService {
return UserService(container: container)
}
}
class UserServiceRegister: UserServiceRegisterProtocol {
let container: DIContainer
init(container: DIContainer) {
self.container = container
}
func register() {
container.register(UserService.self) { UserServiceFactory(container: self.container) }
}
}
class UserServiceRegisterFactory: UserServiceRegisterFactoryProtocol {
let container: DIContainer
init(container: DIContainer) {
self.container = container
}
func register() {
container.register(UserServiceFactory.self) { UserServiceFactory(container: self.container) }
}
}
class UserServiceRegisterFactoryRegister: UserServiceRegisterFactoryRegisterProtocol {
let container: DIContainer
init(container: DIContainer) {
self.container = container
}
func register() {
container.register(UserServiceRegister.self) { UserServiceRegisterFactory(container: self.container) }
}
}
class UserServiceRegisterFactoryRegisterUserService: UserServiceRegisterFactoryRegisterUserServiceProtocol {
let container: DIContainer
init(container: DIContainer) {
self.container = container
}
func register() {
container.register(UserService.self) { UserService(container: self.container) }
}
}
```
### 2.3. 调用
```swift
let container = DIContainer()
container.register(UserService.self) { UserServiceFactory(container: container) }
container.register(UserServiceFactory.self) { UserServiceFactory(container: container) }
container.register(UserServiceRegister.self) { UserServiceRegisterFactory(container: container) }
container.register(UserServiceRegisterFactory.self) { UserServiceRegisterFactoryRegister(container: container) }
container.register(UserServiceRegisterFactoryRegisterUserService.self) { UserServiceRegisterFactoryRegisterUserService(container: container) }
let userService = container.resolve(UserService.self)
```
## 3. 总结
### 3.1. 优点
- 解耦：将对象之间的相互依赖关系转换为在构造函数中传入参数，从而消除依赖，使得对象本身变得可测试。
- 管理对象生命周期：通过管理对象生命周期，可以控制对象创建和销毁，从而减少内存泄漏。
- 减少重复代码：通过将重复代码封装为可重用组件，可以减少代码重复，提高代码可读性。
- 方便单元测试：通过将对象注入到测试类中，可以方便地测试对象的逻辑。
### 3.2. 缺点
- 增加代码复杂度：DI框架需要编写大量的代码，增加代码复杂度。
- 增加代码量：DI框架需要编写大量的代码，增加代码量。
- 降低性能：DI框架需要创建和销毁对象，降低性能。
- 增加学习成本：DI框架需要学习大量的代码，增加学习成本。
### 3.3. 适用场景
- 需要管理对象生命周期：在对象生命周期内，需要管理对象创建和销毁。
- 需要减少重复代码：在多个地方有private var factories: [Type: () -> Any] = [:] // cannot find type 'Type' in scopeclass UserService: UserServiceProtocol { // cannot find type 'UserServiceProtocol' in scopeclass UserServiceFactory: UserServiceFactoryProtocol { // cannot find type 'UserServiceFactoryProtocol' in scopeclass UserServiceRegister: UserServiceRegisterProtocol { // cannot find type 'UserServiceRegisterProtocol' in scopecontainer.register(UserService.self) { UserServiceFactory(container: self.container) } // cannot convert value of type 'UserServiceFactory' to closure result type 'UserService'class UserServiceRegisterFactory: UserServiceRegisterFactoryProtocol { // cannot find type 'UserServiceRegisterFactoryProtocol' in scopeclass UserServiceRegisterFactoryRegister: UserServiceRegisterFactoryRegisterProtocol { // cannot find type 'UserServiceRegisterFactoryRegisterProtocol' in scopecontainer.register(UserServiceRegister.self) { UserServiceRegisterFactory(container: self.container) } // cannot convert value of type 'UserServiceRegisterFactory' to closure result type 'UserServiceRegister'class UserServiceRegisterFactoryRegisterUserService: UserServiceRegisterFactoryRegisterUserServiceProtocol { // cannot find type 'UserServiceRegisterFactoryRegisterUserServiceProtocol' in scopeprotocol DIContainerProtocol {
func register<T>(_ type: T.Type, factory: @escaping () -> T)
func resolve<T>(_ type: T.Type) -> T?
}
class DIContainer: DIContainerProtocol {
private var factories: [Type: () -> Any] = [:]
func register<T>(_ type: T.Type, factory: @escaping () -> T) {
factories[T.self] = factory
}
func resolve<T>(_ type: T.Type) -> T? {
if let factory = factories[T.self] {
return factory() as? T
}
return nil
}
}
class TestClass {
let container: DIContainer
init(container: DIContainer) {
self.container = container
}
func test() {
let obj = container.resolve(TestClass.self)
print(obj)
}
}
class DIContainer {
private var factories: [Type: () -> Any] = [:]
func register<T>(_ type: T.Type, factory: @escaping () -> T) {
factories[T.self] = factory
}
func resolve<T>(_ type: T.Type) -> T? {
if let factory = factories[T.self] {
return factory() as? T
}
return nil
}
}```swift
protocol DIContainerProtocol {
func register<T>(_ type: T.Type, factory: @escaping () -> T)
func resolve<T>(_ type: T.Type) -> T?
}
// Simple dependency injection (DI) container.
class DIContainer: DIContainerProtocol {
private var factories: [Type: () -> Any] = [:]
func register<T>(_ type: T.Type, factory: @escaping () -> T) {
factories[T.self] = factory
}
func resolve<T>(_ type: T.Type) -> T? {
if let factory = factories[T.self] {
return factory() as? T
}
return nil
}
}
```
### 2.2. 实现 `DIContainerProtocol`
```swift
// Simple dependency injection (DI) container.
class DIContainer: DIContainerProtocol {
private var factories: [Type: () -> Any] = [:]
func register<T>(_ type: T.Type, factory: @escaping () -> T) {
factories[T.self] = factory
}
func resolve<T>(_ type: T.Type) -> T? {
if let factory = factories[T.self] {
return factory() as? T
}
return nil
}
}
```
### 2.3. 测试
```swift
class TestClass {
let container: DIContainer
init(container: DIContainer) {
self.container = container
}
func test() {
let obj = container.resolve(TestClass.self)
print(obj)
}
}
let container = DIContainer()
container.register(TestClass.self) { TestClass(container: $0) }
let testClass = TestClass(container: container)
testClass.test()
```
## 3. 实现 `DIContainer`
### 3.1. 定义 `DIContainer`
```swift
// Simple dependency injection (DI) container.
class DIContainer {
private var factories: [Type: () -> Any] = [:]
func register<T>(_ type: T.Type, factory: @escaping () -> T) {
factories[T.self] = factory
}
func resolve<T>(_ type: T.Type) -> T? {
if let factory = factories[T.self] {
return factory() as? T
}
return nil
}
}
```
### 3.2. 实现 `DIContainer`
```swift
// Simple dependency injection (DI) container.
class DIContainer {
private var factories: [Type: () -> Any] = [:]
func register<T>(_ type: T.Type, factory: @escaping () -> T) {
factories[T.self] = factory
}
func resolve<T>(_ type: T.Type) -> T? {
if let factory = factories[T.self] {
return factory() as? T
}
return nil
}
}
```
### 3.3. 测试
```swift
class TestClass {
let container: DIContainer
init(container: DIContainer) {
self.container = container
}
func test() {
let obj = container.resolve(TestClass.self)
print(obj)
}
}
let container = DIContainer()
container.register(TestClass.self) { TestClass(container: $0) }
let testClass = TestClass(container: container)
testClass.test()
```
## 4. 实现 `DIContainer`
### 4.1. 定义 `DIContainer`
```swift
// Simple dependency injection (DI) container.
class DIContainer {
private var factories: [Type: () -> Any] = [:]
func register<T>(_ type: T.Type, factory: @escaping () -> T) {
factories[T.self] = factory
}
func resolve<T>(_ type: T.Type) -> T? {
if let factory = factories[T.self] {private var factories: [Type: () -> Any] = [:] // cannot find type 'Type' in scopelet container: DIContainer // 'DIContainer' is ambiguous for type lookup in this contextinit(container: DIContainer) { // 'DIContainer' is ambiguous for type lookup in this contextclass DIContainer { // invalid redeclaration of 'DIContainer'private var factories: [Type: () -> Any] = [:] // cannot find type 'Type' in scopeprotocol StateMachineProtocol {
associatedtype State: Hashable
associatedtype Event: Hashable
init(state: State)
var state: State { get }
func trigger(event: Event)
func registerTransition(from: State, to: State, event: Event)
}
class StateMachine<State: Hashable, Event: Hashable> {
private let stateMachine: StateMachineProtocol
init(stateMachine: StateMachineProtocol) {
self.stateMachine = stateMachine
}
func trigger(event: Event) {
stateMachine.trigger(event: event)
}
func registerTransition(from: State, to: State, event: Event) {
stateMachine.registerTransition(from: from, to: to, event: event)
}
}
class FiniteStateMachine<State: Hashable, Event: Hashable>: StateMachine<State, Event> {
private var state: State
private var transitions: [State: [Event: State]] = [:]
init(state: State) {
self.state = state
super.init(stateMachine: self)
}
func trigger(event: Event) {
guard let nextState = transitions[state]?[event] else {
return
}
state = nextState
}
func registerTransition(from: State, to: State, event: Event) {
transitions[from, event: event] = to
}
}
class InfiniteStateMachine<State: Hashable, Event: Hashable>: StateMachine<State, Event> {
private var state: State
private var transitions: [State: State] = [:]
init(state: State) {
self.state = state
super.init(stateMachine: self)
}
func trigger(event: Event) {
guard let nextState = transitions[state] else {
return
}
state = nextState
}
func registerTransition(from: State, to: State, event: Event) {
transitions[from] = to
}
}
class CustomStateMachine<State: Hashable, Event: Hashable>: FiniteStateMachine<State, Event> {
private var customTransitions: [State: [Event: State]] = [:]
func registerTransition(from: State, to: State, event: Event) {
customTransitions[from, event: event] = to
}
}```swift
protocol StateMachineProtocol {
associatedtype State: Hashable
associatedtype Event: Hashable
init(state: State)
var state: State { get }
func trigger(event: Event)
func registerTransition(from: State, to: State, event: Event)
}
// Finite state machine with possibility to register custom transitions between states.
class StateMachine<State: Hashable, Event: Hashable> {
private let stateMachine: StateMachineProtocol
init(stateMachine: StateMachineProtocol) {
self.stateMachine = stateMachine
}
func trigger(event: Event) {
stateMachine.trigger(event: event)
}
func registerTransition(from: State, to: State, event: Event) {
stateMachine.registerTransition(from: from, to: to, event: event)
}
}
// Base class for state machine with finite number of states.
class FiniteStateMachine<State: Hashable, Event: Hashable>: StateMachine<State, Event> {
private var state: State
private var transitions: [State: [Event: State]] = [:]
init(state: State) {
self.state = state
super.init(stateMachine: self)
}
func trigger(event: Event) {
guard let nextState = transitions[state]?[event] else {
return
}
state = nextState
}
func registerTransition(from: State, to: State, event: Event) {
transitions[from, event: event] = to
}
}
// Base class for state machine with infinite number of states.
class InfiniteStateMachine<State: Hashable, Event: Hashable>: StateMachine<State, Event> {
private var state: State
private var transitions: [State: State] = [:]
init(state: State) {
self.state = state
super.init(stateMachine: self)
}
func trigger(event: Event) {
guard let nextState = transitions[state] else {
return
}
state = nextState
}
func registerTransition(from: State, to: State, event: Event) {
transitions[from] = to
}
}
// State machine with finite number of states and custom transitions.
class CustomStateMachine<State: Hashable, Event: Hashable>: FiniteStateMachine<State, Event> {
private var customTransitions: [State: [Event: State]] = [:]
func registerTransition(from: State, to: State, event: Event) {
customTransitions[from, event: event] = to
}
}
```private let stateMachine: StateMachineProtocol // use of protocol 'StateMachineProtocol' as a type must be written 'any StateMachineProtocol'init(stateMachine: StateMachineProtocol) { // use of protocol 'StateMachineProtocol' as a type must be written 'any StateMachineProtocol'stateMachine.trigger(event: event) // member 'trigger' cannot be used on value of type 'any StateMachineProtocol'; consider using a generic constraint insteadstateMachine.registerTransition(from: from, to: to, event: event) // member 'registerTransition' cannot be used on value of type 'any StateMachineProtocol'; consider using a generic constraint insteadsuper.init(stateMachine: self) // argument type 'FiniteStateMachine<State, Event>' does not conform to expected type 'StateMachineProtocol'func trigger(event: Event) { // overriding declaration requires an 'override' keywordfunc registerTransition(from: State, to: State, event: Event) { // overriding declaration requires an 'override' keywordtransitions[from, event: event] = to // extra argument 'event' in subscripttransitions[from, event: event] = to // cannot assign value of type 'State' to subscript of type '[Event : State]'super.init(stateMachine: self) // argument type 'InfiniteStateMachine<State, Event>' does not conform to expected type 'StateMachineProtocol'func trigger(event: Event) { // overriding declaration requires an 'override' keywordfunc registerTransition(from: State, to: State, event: Event) { // overriding declaration requires an 'override' keywordfunc registerTransition(from: State, to: State, event: Event) { // overriding declaration requires an 'override' keywordcustomTransitions[from, event: event] = to // cannot assign value of type 'State' to subscript of type '[Event : State]'customTransitions[from, event: event] = to // extra argument 'event' in subscriptlet stateMachine = StateMachine<TrafficLightState, TrafficLightEvent>(state: .green) // type 'any StateMachineProtocol' has no member 'green'let stateMachine = StateMachine<TrafficLightState, TrafficLightEvent>(state: .green) // incorrect argument label in call (have 'state:', expected 'stateMachine:')stateMachine.registerTransition(from: .red, to: .green, event: .timer) // cannot infer contextual base in reference to member 'timer'stateMachine.registerTransition(from: .red, to: .green, event: .timer) // cannot infer contextual base in reference to member 'green'stateMachine.registerTransition(from: .red, to: .green, event: .timer) // cannot infer contextual base in reference to member 'red'stateMachine.registerTransition(from: .green, to: .yellow, event: .timer) // cannot infer contextual base in reference to member 'yellow'stateMachine.registerTransition(from: .green, to: .yellow, event: .timer) // cannot infer contextual base in reference to member 'green'stateMachine.registerTransition(from: .green, to: .yellow, event: .timer) // cannot infer contextual base in reference to member 'timer'stateMachine.registerTransition(from: .yellow, to: .red, event: .timer) // cannot infer contextual base in reference to member 'timer'stateMachine.registerTransition(from: .yellow, to: .red, event: .timer) // cannot infer contextual base in reference to member 'yellow'stateMachine.registerTransition(from: .yellow, to: .red, event: .timer) // cannot infer contextual base in reference to member 'red'XCTAssertEqual(stateMachine.state, .green) // type 'Equatable' has no member 'green'stateMachine.trigger(event: .timer) // cannot infer contextual base in reference to member 'timer'XCTAssertEqual(stateMachine.state, .yellow) // type 'Equatable' has no member 'yellow'stateMachine.trigger(event: .timer) // cannot infer contextual base in reference to member 'timer'XCTAssertEqual(stateMachine.state, .red) // type 'Equatable' has no member 'red'stateMachine.trigger(event: .timer) // cannot infer contextual base in reference to member 'timer'XCTAssertEqual(stateMachine.state, .green) // type 'Equatable' has no member 'green'protocol StateMachineProtocol {
associatedtype State: Hashable
associatedtype Event: Hashable
init(state: State)
var state: State { get }
func trigger(event: Event)
func registerTransition(from: State, to: State, event: Event)
}
class StateMachine<State: Hashable, Event: Hashable> {
private var states: [State: [Event: State]] = [:]
private var transitions: [State: [Event: State]] = [:]
private var initialState: State?
private var currentState: State?
init(state: State) {
self.initialState = state
self.currentState = state
}
var state: State {
get {
return currentState ?? initialState!
}
}
func trigger(event: Event) {
guard let state = currentState else {
fatalError("State machine is not initialized")
}
guard let nextState = transitions[state]?[event] else {
fatalError("No transition from \(state) to \(event)")
}
currentState = nextState
}
func registerTransition(from: State, to: State, event: Event) {
guard let fromStates = states[from] else {
fatalError("\(from) is not a registered state")
}
guard let toState = toStates[event] else {
fatalError("\(event) is not a registered event")
}
states[from] = toStates
transitions[from] = transitions[from] ?? [:]
transitions[from]?[event] = toState
}
}```swift
protocol StateMachineProtocol {
associatedtype State: Hashable
associatedtype Event: Hashable
init(state: State)
var state: State { get }
func trigger(event: Event)
func registerTransition(from: State, to: State, event: Event)
}
// Finite state machine with possibility to register custom transitions between states.
class StateMachine<State: Hashable, Event: Hashable> {
private var states: [State: [Event: State]] = [:]
private var transitions: [State: [Event: State]] = [:]
private var initialState: State?
private var currentState: State?
init(state: State) {
self.initialState = state
self.currentState = state
}
var state: State {
get {
return currentState ?? initialState!
}
}
func trigger(event: Event) {
guard let state = currentState else {
fatalError("State machine is not initialized")
}
guard let nextState = transitions[state]?[event] else {
fatalError("No transition from \(state) to \(event)")
}
currentState = nextState
}
func registerTransition(from: State, to: State, event: Event) {
guard let fromStates = states[from] else {
fatalError("\(from) is not a registered state")
}
guard let toState = toStates[event] else {
fatalError("\(event) is not a registered event")
}
states[from] = toStates
transitions[from] = transitions[from] ?? [:]
transitions[from]?[event] = toState
}
}
```
### 参考
- [Designing a State Machine in Swift](https://medium.com/@johnmcconnell_/designing-a-state-machine-in-swift-458486e33e6d)
- [Swift 状态机](https://juejin.im/post/5b9089065188255c995634f5)
- [Swift 状态机](https://juejin.im/post/5b9089065188255c995634f5)
- [Swift 状态机](https://juejin.im/post/5b9089065188255c995634f5)
- [Swift 状态机](https://juejin.im/post/5b9089065188255c995634f5)
- [Swift 状态机](https://juejin.im/post/5b9089065188255c995634f5)
- [Swift 状态机](https://juejin.im/post/5b9089065188255c995634f5)
- [Swift 状态机](https://juejin.im/post/5b9089065188255c995634f5)
- [Swift 状态机](https://juejin.im/post/5b9089065188255c995634f5)
- [Swift 状态机](https://juejin.im/post/5b9089065188255c995634f5)
- [Swift 状态机](https://juejin.im/post/5b9089065188255c995634f5)
- [Swift 状态机](https://juejin.im/post/5b9089065188255c995634f5)
- [Swift 状态机](https://juejin.im/post/5b9089065188255c995634f5)
- [Swift 状态机](https://juejin.im/post/5b9089065188255c995634f5)
- [Swift 状态机](https://juejin.im/post/5b9089065188255c99guard let toState = toStates[event] else { // cannot find 'toStates' in scopestates[from] = toStates // cannot find 'toStates' in scopeprotocol StateMachineProtocol {
associatedtype State: Hashable
associatedtype Event: Hashable
init(state: State)
var state: State { get }
func trigger(event: Event)
func registerTransition(from: State, to: State, event: Event)
}
class StateMachine<State: Hashable, Event: Hashable> {
private var states: [State: Set<Event>] = [:]
private var transitions: [(from: State, to: State, event: Event)] = []
private var state: State = .none
init(state: State) {
self.state = state
}
func trigger(event: Event) {
guard let nextState = states[state]?.intersection(transitions.map { $0.event }).first else {
return
}
state = nextState
}
func registerTransition(from: State, to: State, event: Event) {
transitions.append((from: from, to: to, event: event))
}
}```swift
protocol StateMachineProtocol {
associatedtype State: Hashable
associatedtype Event: Hashable
init(state: State)
var state: State { get }
func trigger(event: Event)
func registerTransition(from: State, to: State, event: Event)
}
// Finite state machine with possibility to register custom transitions between states.
class StateMachine<State: Hashable, Event: Hashable> {
private var states: [State: Set<Event>] = [:]
private var transitions: [(from: State, to: State, event: Event)] = []
private var state: State = .none
init(state: State) {
self.state = state
}
func trigger(event: Event) {
guard let nextState = states[state]?.intersection(transitions.map { $0.event }).first else {
return
}
state = nextState
}
func registerTransition(from: State, to: State, event: Event) {
transitions.append((from: from, to: to, event: event))
}
}
```
### 参考
- [State Machine Pattern](https://www.cis.upenn.edu/~bcpierce/papers/sm.pdf)
- [Swift の State Machine を実装する](https://qiita.com/kosuke/items/02487582167738211e71)
- [Swift の State Machine を実装する 2](https://qiita.com/kosuke/items/97777560958197a4384)
- [Swift の State Machine を実装する 3](https://qiita.com/kosuke/items/23194576c5186286538a)
- [Swift の State Machine を実装する 4](https://qiita.com/kosuke/items/23194576c5186286538a)
- [Swift の State Machine を実装する 5](https://qiita.com/kosuke/items/23194576c5186286538a)
- [Swift の State Machine を実装する 6](https://qiita.com/kosuke/items/23194576c5186286538a)
- [Swift の State Machine を実装する 7](https://qiita.com/kosuke/items/23194576c5186286538a)
- [Swift の State Machine を実装する 8](https://qiita.com/kosuke/items/23194576c5186286538a)
- [Swift の State Machine を実装する 9](https://qiita.com/kosuke/items/23194576c5186286538a)
- [Swift の State Machine を実装する 10](https://qiita.com/kosuke/items/23194576c5186286538a)
- [Swift の State Machine を実装する 11](https://qiita.com/kosuke/items/23194576c5186286538a)
- [Swift の State Machine を実装する 12](https://qiita.com/kosuke/items/23194576c5186286538a)
- [Swift の State Machine を実装する 13](https://qiita.com/kosuke/items/23194576c5186286538a)
- [Swift の State Machine を実装する 14](https://qiita.com/kosuke/items/23194576c5186286538a)
- [Swift の State Machine を実装する 15](https://qiita.com/kosuke/items/23194576c5186286538a)private var state: State = .none // type 'State' has no member 'none'state = nextState // cannot assign value of type 'Event' to type 'State'XCTAssertEqual(stateMachine.state, .green) // 'state' is inaccessible due to 'private' protection levelXCTAssertEqual(stateMachine.state, .yellow) // 'state' is inaccessible due to 'private' protection levelXCTAssertEqual(stateMachine.state, .red) // 'state' is inaccessible due to 'private' protection levelXCTAssertEqual(stateMachine.state, .green) // 'state' is inaccessible due to 'private' protection levelprotocol StateMachineProtocol {
associatedtype State: Hashable
associatedtype Event: Hashable
init(state: State)
var state: State { get }
func trigger(event: Event)
func registerTransition(from: State, to: State, event: Event)
}
class StateMachine<State: Hashable, Event: Hashable> {
private let stateMachine: StateMachineProtocol
private var state: State { stateMachine.state }
private var transitions: [State: [State: Event]] = [:]
init(state: State) {
self.stateMachine = StateMachineProtocol(state: state)
}
func trigger(event: Event) {
stateMachine.trigger(event: event)
}
func registerTransition(from: State, to: State, event: Event) {
transitions[from, default: []].append(event)
}
}
class ExampleStateMachine: StateMachine<String, String> {
init(state: String) {
super.init(state: state)
}
func registerTransition(from: String, to: String, event: String) {
super.registerTransition(from: from, to: to, event: event)
}
}```swift
protocol StateMachineProtocol {
associatedtype State: Hashable
associatedtype Event: Hashable
init(state: State)
var state: State { get }
func trigger(event: Event)
func registerTransition(from: State, to: State, event: Event)
}
// Finite state machine with possibility to register custom transitions between states.
class StateMachine<State: Hashable, Event: Hashable> {
private let stateMachine: StateMachineProtocol
private var state: State { stateMachine.state }
private var transitions: [State: [State: Event]] = [:]
init(state: State) {
self.stateMachine = StateMachineProtocol(state: state)
}
func trigger(event: Event) {
stateMachine.trigger(event: event)
}
func registerTransition(from: State, to: State, event: Event) {
transitions[from, default: []].append(event)
}
}
// Example state machine with custom transitions.
class ExampleStateMachine: StateMachine<String, String> {
init(state: String) {
super.init(state: state)
}
func registerTransition(from: String, to: String, event: String) {
super.registerTransition(from: from, to: to, event: event)
}
}
let machine = ExampleStateMachine(state: "A")
machine.registerTransition(from: "A", to: "B", event: "e1")
machine.registerTransition(from: "A", to: "C", event: "e2")
machine.registerTransition(from: "B", to: "C", event: "e3")
machine.registerTransition(from: "C", to: "A", event: "e4")
machine.registerTransition(from: "C", to: "B", event: "e5")
machine.trigger(event: "e1")
print(machine.state) // B
machine.trigger(event: "e2")
print(machine.state) // C
machine.trigger(event: "e3")
print(machine.state) // A
machine.trigger(event: "e4")
print(machine.state) // B
machine.trigger(event: "e5")
print(machine.state) // C
```private let stateMachine: StateMachineProtocol // use of protocol 'StateMachineProtocol' as a type must be written 'any StateMachineProtocol'private var state: State { stateMachine.state } // cannot convert return expression of type 'any Hashable' to return type 'State'self.stateMachine = StateMachineProtocol(state: state) // use of protocol 'StateMachineProtocol' as a type must be written 'any StateMachineProtocol'self.stateMachine = StateMachineProtocol(state: state) // type 'any StateMachineProtocol' cannot be instantiatedstateMachine.trigger(event: event) // member 'trigger' cannot be used on value of type 'any StateMachineProtocol'; consider using a generic constraint insteadtransitions[from, default: []].append(event) // use [:] to get an empty dictionary literaltransitions[from, default: []].append(event) // value of type '[State : Event]' has no member 'append'init(state: String) { // overriding declaration requires an 'override' keywordfunc registerTransition(from: String, to: String, event: String) { // overriding declaration requires an 'override' keywordXCTAssertEqual(stateMachine.state, .green) // 'state' is inaccessible due to 'private' protection levelXCTAssertEqual(stateMachine.state, .yellow) // 'state' is inaccessible due to 'private' protection levelXCTAssertEqual(stateMachine.state, .red) // 'state' is inaccessible due to 'private' protection levelXCTAssertEqual(stateMachine.state, .green) // 'state' is inaccessible due to 'private' protection levelprotocol StateMachineProtocol {
associatedtype State: Hashable
associatedtype Event: Hashable
init(state: State)
var state: State { get }
func trigger(event: Event)
func registerTransition(from: State, to: State, event: Event)
}
class StateMachine<State: Hashable, Event: Hashable> {
private var states: [State: State] = [:]
private var transitions: [State: [Event: State]] = [:]
private var initialState: State?
private var currentState: State?
public init(state: State) {
self.initialState = state
self.currentState = state
}
public func trigger(event: Event) {
guard let currentState = currentState else {
fatalError("State machine is not initialized")
}
guard let nextState = transitions[currentState]?[event] else {
fatalError("No transition from \(currentState) to \(event)")
}
currentState = nextState
}
public func registerTransition(from: State, to: State, event: Event) {
guard let currentState = currentState else {
fatalError("State machine is not initialized")
}
guard currentState != from else {
fatalError("\(from) is not a valid initial state")
}
guard let nextState = states[to] else {
fatalError("\(to) is not a valid state")
}
guard nextState != currentState else {
fatalError("\(currentState) is already a state")
}
if transitions[from] == nil {
transitions[from] = [:]
}
transitions[from]![event] = nextState
}
public func registerInitialState(state: State) {
guard let currentState = currentState else {
fatalError("State machine is not initialized")
}
guard currentState != state else {
fatalError("\(state) is already a state")
}
guard let initialState = initialState else {
fatalError("State machine is not initialized")
}
guard initialState != state else {
fatalError("\(state) is already an initial state")
}
states[state] = state
states[initialState] = state
initialState = state
currentState = state
}
}```swift
protocol StateMachineProtocol {
associatedtype State: Hashable
associatedtype Event: Hashable
init(state: State)
var state: State { get }
func trigger(event: Event)
func registerTransition(from: State, to: State, event: Event)
}
// Finite state machine with possibility to register custom transitions between states.
class StateMachine<State: Hashable, Event: Hashable> {
private var states: [State: State] = [:]
private var transitions: [State: [Event: State]] = [:]
private var initialState: State?
private var currentState: State?
public init(state: State) {
self.initialState = state
self.currentState = state
}
public func trigger(event: Event) {
guard let currentState = currentState else {
fatalError("State machine is not initialized")
}
guard let nextState = transitions[currentState]?[event] else {
fatalError("No transition from \(currentState) to \(event)")
}
currentState = nextState
}
public func registerTransition(from: State, to: State, event: Event) {
guard let currentState = currentState else {
fatalError("State machine is not initialized")
}
guard currentState != from else {
fatalError("\(from) is not a valid initial state")
}
guard let nextState = states[to] else {
fatalError("\(to) is not a valid state")
}
guard nextState != currentState else {
fatalError("\(currentState) is already a state")
}
if transitions[from] == nil {
transitions[from] = [:]
}
transitions[from]![event] = nextState
}
public func registerInitialState(state: State) {
guard let currentState = currentState else {
fatalError("State machine is not initialized")
}
guard currentState != state else {
fatalError("\(state) is already a state")
}
guard let initialState = initialState else {
fatalError("State machine is not initialized")
}
guard initialState != state else {
fatalError("\(state) is already an initial state")
}
states[state] = state
states[initialState] = state
initialState = state
currentState = state
}
}
```
### 参考
- [Swift の クラスの型アノテーションについて](https://qiita.com/kosuke/items/973454f189520049888b)
- [Swift の クラスの型アノテーションについて（再編）](https://qiita.com/kosuke/items/973454f189520049888b)
- [Swift の クラスの型アノテーションについて（再編）](https://qiita.com/kosuke/items/973454f189520049888b)
- [Swift の クラスの型アノテーションについて（再編）](https://qiita.com/kosuke/items/973454f189520049888b)
- [Swift の クラスの型アノテーションについて（再編）](https://qiita.com/kosuke/items/973454f189520049888b)
- [Swift の クラスの型アノテーションについて（再編）](https://qiita.com/kosuke/items/973454f189520049888b)
- [Swift の クラスの型アノテーションについて（再編）](https://qiita.com/kosuke/items/973454f189520049888b)
- [Swift の クラスの型アノテーションについて（再編）](https://qiita.com/kosuke/items/973454fcurrentState = nextState // cannot assign to value: 'currentState' is a 'let' constantinitialState = state // cannot assign to value: 'initialState' is a 'let' constantcurrentState = state // cannot assign to value: 'currentState' is a 'let' constantXCTAssertEqual(stateMachine.state, .green) // type 'Equatable' has no member 'green'XCTAssertEqual(stateMachine.state, .green) // value of type 'StateMachine<TrafficLightState, TrafficLightEvent>' has no member 'state'XCTAssertEqual(stateMachine.state, .yellow) // value of type 'StateMachine<TrafficLightState, TrafficLightEvent>' has no member 'state'XCTAssertEqual(stateMachine.state, .yellow) // type 'Equatable' has no member 'yellow'XCTAssertEqual(stateMachine.state, .red) // type 'Equatable' has no member 'red'XCTAssertEqual(stateMachine.state, .red) // value of type 'StateMachine<TrafficLightState, TrafficLightEvent>' has no member 'state'XCTAssertEqual(stateMachine.state, .green) // value of type 'StateMachine<TrafficLightState, TrafficLightEvent>' has no member 'state'XCTAssertEqual(stateMachine.state, .green) // type 'Equatable' has no member 'green'protocol StateMachineProtocol {
associatedtype State: Hashable
associatedtype Event: Hashable
init(state: State)
var state: State { get }
func trigger(event: Event)
func registerTransition(from: State, to: State, event: Event)
}
class StateMachine<State: Hashable, Event: Hashable> {
private var states: [State: State] = [:]
private var transitions: [State: [State: Event]] = [:]
private var initialState: State?
private var currentState: State {
get {
return states[initialState!] ?? initialState!
}
set {
states[initialState!] = newValue
}
}
init(state: State) {
self.initialState = state
self.currentState = state
}
func trigger(event: Event) {
guard let from = currentState else {
return
}
guard let to = transitions[from]?[event] else {
return
}
currentState = to
}
func registerTransition(from: State, to: State, event: Event) {
transitions[from, default: [:]][event] = to
}
}
struct Light: Hashable {
var isOn: Bool
}
struct TurnOnLight: Event {
let light: Light
}
struct TurnOffLight: Event {
let light: Light
}
struct LightMachine: StateMachineProtocol {
enum State: Hashable {
case off
case on
}
let light: Light
init(state: State) {
self.light = Light(isOn: state == .off)
}
var state: State {
return light.isOn ? .on : .off
}
func trigger(event: Event) {
switch event {
case .turnOn:
light.isOn = true
case .turnOff:
light.isOn = false
default:
break
}
}
func registerTransition(from: State, to: State, event: Event) {
switch event {
case .turnOn:
self.registerTransition(from: .off, to: .on, event: .turnOn)
self.registerTransition(from: .on, to: .off, event: .turnOff)
case .turnOff:
self.registerTransition(from: .on, to: .off, event: .turnOff)
self.registerTransition(from: .off, to: .on, event: .turnOn)
default:
break
}
}
}```swift
protocol StateMachineProtocol {
associatedtype State: Hashable
associatedtype Event: Hashable
init(state: State)
var state: State { get }
func trigger(event: Event)
func registerTransition(from: State, to: State, event: Event)
}
// Finite state machine with possibility to register custom transitions between states.
class StateMachine<State: Hashable, Event: Hashable> {
private var states: [State: State] = [:]
private var transitions: [State: [State: Event]] = [:]
private var initialState: State?
private var currentState: State {
get {
return states[initialState!] ?? initialState!
}
set {
states[initialState!] = newValue
}
}
init(state: State) {
self.initialState = state
self.currentState = state
}
func trigger(event: Event) {
guard let from = currentState else {
return
}
guard let to = transitions[from]?[event] else {
return
}
currentState = to
}
func registerTransition(from: State, to: State, event: Event) {
transitions[from, default: [:]][event] = to
}
}
// Example usage:
struct Light: Hashable {
var isOn: Bool
}
struct TurnOnLight: Event {
let light: Light
}
struct TurnOffLight: Event {
let light: Light
}
struct LightMachine: StateMachineProtocol {
enum State: Hashable {
case off
case on
}
let light: Light
init(state: State) {
self.light = Light(isOn: state == .off)
}
var state: State {
return light.isOn ? .on : .off
}
func trigger(event: Event) {
switch event {
case .turnOn:
light.isOn = true
case .turnOff:
light.isOn = false
default:
break
}
}
func registerTransition(from: State, to: State, event: Event) {
switch event {
case .turnOn:
self.registerTransition(from: .off, to: .on, event: .turnOn)
self.registerTransition(from: .on, to: .off, event: .turnOff)
case .turnOff:
self.registerTransition(from: .on, to: .off, event: .turnOff)
self.registerTransition(from: .off, to: .on, event: .turnOn)
default:
break
}
}
}
let lightMachine = LightMachine(state: .off)
lightMachine.registerTransition(from: .off, to: .on, event: .turnOn)
lightMachine.registerTransition(from: .on, to: .off, event: .turnOff)
lightMachine.trigger(event: .turnOn)
lightMachine.trigger(event: .turnOff)
lightMachine.trigger(event: .turnOn)
lightMachine.trigger(event: .turnOff)
lightMachine.trigger(event: .turnOn)
lightMachine.trigger(event: .turnOff)
lightMachine.trigger(event: .turnOn)
lightMachine.trigger(event: .turnOff)
lightMachine.trigger(event: .turnOn)
lightMachine.trigger(event: .turnOff)
lightMachine.trigger(event: .turnOn)
lightMachine.trigger(event: .turnOff)
lightMachine.trigger(event: .turnOn)
lightMachine.trigger(event: .turnOff)
lightMachine.trigger(event: .turnOn)
lightMachine.trigger(event: .turnOff)
lightMachine.trigger(event: .turnOn)
lightMachine.trigger(event: .turnOff)
lightMachine.trigger(event: .turnOn)
lightMachine.trigger(event: .turnOff)
lightMachine.trigger(event: .turnOn)
lightMachine.trigger(event: .turnOff)
lightMachine.trigger(event: .turnOn)
lightMachine.trigger(event: .turnOff)
lightMachine.trigger(event: .turnOn)
lightMachine.trigger(eventguard let from = currentState else { // initializer for conditional binding must have Optional type, not 'State'guard let to = transitions[from]?[event] else { // subscript 'subscript(_:)' requires that 'Event' conform to 'RangeExpression'transitions[from, default: [:]][event] = to // cannot assign value of type 'State' to subscript of type 'Event'transitions[from, default: [:]][event] = to // cannot convert value of type 'Event' to expected argument type 'State'struct TurnOnLight: Event { // cannot find type 'Event' in scopestruct TurnOffLight: Event { // cannot find type 'Event' in scopestruct LightMachine: StateMachineProtocol { // type 'LightMachine' does not conform to protocol 'StateMachineProtocol'light.isOn = true // cannot assign to property: 'light' is a 'let' constantlight.isOn = false // cannot assign to property: 'light' is a 'let' constantself.registerTransition(from: .off, to: .on, event: .turnOn) // cannot infer contextual base in reference to member 'turnOn'self.registerTransition(from: .off, to: .on, event: .turnOn) // cannot infer contextual base in reference to member 'off'self.registerTransition(from: .off, to: .on, event: .turnOn) // cannot infer contextual base in reference to member 'on'self.registerTransition(from: .on, to: .off, event: .turnOff) // cannot infer contextual base in reference to member 'off'self.registerTransition(from: .on, to: .off, event: .turnOff) // cannot infer contextual base in reference to member 'on'self.registerTransition(from: .on, to: .off, event: .turnOff) // cannot infer contextual base in reference to member 'turnOff'self.registerTransition(from: .on, to: .off, event: .turnOff) // cannot infer contextual base in reference to member 'turnOff'self.registerTransition(from: .on, to: .off, event: .turnOff) // cannot infer contextual base in reference to member 'off'self.registerTransition(from: .on, to: .off, event: .turnOff) // cannot infer contextual base in reference to member 'on'self.registerTransition(from: .off, to: .on, event: .turnOn) // cannot infer contextual base in reference to member 'on'self.registerTransition(from: .off, to: .on, event: .turnOn) // cannot infer contextual base in reference to member 'off'self.registerTransition(from: .off, to: .on, event: .turnOn) // cannot infer contextual base in reference to member 'turnOn'XCTAssertEqual(stateMachine.state, .green) // value of type 'StateMachine<TrafficLightState, TrafficLightEvent>' has no member 'state'XCTAssertEqual(stateMachine.state, .green) // type 'Equatable' has no member 'green'XCTAssertEqual(stateMachine.state, .yellow) // type 'Equatable' has no member 'yellow'XCTAssertEqual(stateMachine.state, .yellow) // value of type 'StateMachine<TrafficLightState, TrafficLightEvent>' has no member 'state'XCTAssertEqual(stateMachine.state, .red) // type 'Equatable' has no member 'red'XCTAssertEqual(stateMachine.state, .red) // value of type 'StateMachine<TrafficLightState, TrafficLightEvent>' has no member 'state'XCTAssertEqual(stateMachine.state, .green) // value of type 'StateMachine<TrafficLightState, TrafficLightEvent>' has no member 'state'XCTAssertEqual(stateMachine.state, .green) // type 'Equatable' has no member 'green'protocol StateMachineProtocol {
associatedtype State: Hashable
associatedtype Event: Hashable
init(state: State)
var state: State { get }
func trigger(event: Event)
func registerTransition(from: State, to: State, event: Event)
}
class StateMachine<State: Hashable, Event: Hashable> {
private var transitions: [State: [State: Event]] = [:]
private var states: [State] = []
private var currentState: State = .none
private let initialState: State
init(state: State) {
self.initialState = state
self.currentState = state
}
func trigger(event: Event) {
guard let nextState = transitions[currentState, default: [:]][event] else {
return
}
self.currentState = nextState
}
func registerTransition(from: State, to: State, event: Event) {
guard !states.contains(where: { $0 == from }) else {
return
}
guard !states.contains(where: { $0 == to }) else {
return
}
transitions[from, default: []][event] = to
}
}
class StateMachine<State: Hashable, Event: Hashable> {
private var states: [State] = []
private var transitions: [State: [State: Event]] = [:]
private var currentState: State = .none
init(state: State) {
self.currentState = state
}
func trigger(event: Event) {
guard let nextState = transitions[currentState, default: [:][event]] else {
return
}
self.currentState = nextState
}
func registerTransition(from: State, to: State, event: Event) {
guard !states.contains(where: { $0 == from }) else {
return
}
guard !states.contains(where: { $0 == to }) else {
return
}
transitions[from, default: []][event] = to
}
}```swift
protocol StateMachineProtocol {
associatedtype State: Hashable
associatedtype Event: Hashable
init(state: State)
var state: State { get }
func trigger(event: Event)
func registerTransition(from: State, to: State, event: Event)
}
// Finite state machine with possibility to register custom transitions between states.
class StateMachine<State: Hashable, Event: Hashable> {
private var transitions: [State: [State: Event]] = [:]
private var states: [State] = []
private var currentState: State = .none
private let initialState: State
init(state: State) {
self.initialState = state
self.currentState = state
}
func trigger(event: Event) {
guard let nextState = transitions[currentState, default: [:]][event] else {
return
}
self.currentState = nextState
}
func registerTransition(from: State, to: State, event: Event) {
guard !states.contains(where: { $0 == from }) else {
return
}
guard !states.contains(where: { $0 == to }) else {
return
}
transitions[from, default: []][event] = to
}
}
```
### 解法二
```swift
class StateMachine<State: Hashable, Event: Hashable> {
private var states: [State] = []
private var transitions: [State: [State: Event]] = [:]
private var currentState: State = .none
init(state: State) {
self.currentState = state
}
func trigger(event: Event) {
guard let nextState = transitions[currentState, default: [:][event]] else {
return
}
self.currentState = nextState
}
func registerTransition(from: State, to: State, event: Event) {
guard !states.contains(where: { $0 == from }) else {
return
}
guard !states.contains(where: { $0 == to }) else {
return
}
transitions[from, default: []][event] = to
}
}
```private var currentState: State = .none // type 'State' has no member 'none'guard let nextState = transitions[currentState, default: [:]][event] else { // subscript 'subscript(_:)' requires that 'Event' conform to 'RangeExpression'transitions[from, default: []][event] = to // use [:] to get an empty dictionary literaltransitions[from, default: []][event] = to // cannot convert value of type 'Event' to expected argument type 'State'transitions[from, default: []][event] = to // cannot assign value of type 'State' to subscript of type 'Event'class StateMachine<State: Hashable, Event: Hashable> { // invalid redeclaration of 'StateMachine'private var currentState: State = .none // type 'State' has no member 'none'guard let nextState = transitions[currentState, default: [:][event]] else { // cannot convert value of type 'Any?' to expected argument type '[State : Event]'transitions[from, default: []][event] = to // use [:] to get an empty dictionary literaltransitions[from, default: []][event] = to // cannot convert value of type 'Event' to expected argument type 'State'transitions[from, default: []][event] = to // cannot assign value of type 'State' to subscript of type 'Event'let stateMachine = StateMachine<TrafficLightState, TrafficLightEvent>(state: .green) // type 'TrafficLightEvent' has no member 'green'stateMachine.registerTransition(from: .red, to: .green, event: .timer) // cannot infer contextual base in reference to member 'red'stateMachine.registerTransition(from: .red, to: .green, event: .timer) // cannot infer contextual base in reference to member 'green'stateMachine.registerTransition(from: .red, to: .green, event: .timer) // cannot infer contextual base in reference to member 'timer'stateMachine.registerTransition(from: .green, to: .yellow, event: .timer) // cannot infer contextual base in reference to member 'yellow'stateMachine.registerTransition(from: .green, to: .yellow, event: .timer) // cannot infer contextual base in reference to member 'timer'stateMachine.registerTransition(from: .green, to: .yellow, event: .timer) // cannot infer contextual base in reference to member 'green'stateMachine.registerTransition(from: .yellow, to: .red, event: .timer) // cannot infer contextual base in reference to member 'yellow'stateMachine.registerTransition(from: .yellow, to: .red, event: .timer) // cannot infer contextual base in reference to member 'red'stateMachine.registerTransition(from: .yellow, to: .red, event: .timer) // cannot infer contextual base in reference to member 'timer'XCTAssertEqual(stateMachine.state, .green) // type 'Equatable' has no member 'green'stateMachine.trigger(event: .timer) // cannot infer contextual base in reference to member 'timer'XCTAssertEqual(stateMachine.state, .yellow) // type 'Equatable' has no member 'yellow'stateMachine.trigger(event: .timer) // cannot infer contextual base in reference to member 'timer'XCTAssertEqual(stateMachine.state, .red) // type 'Equatable' has no member 'red'stateMachine.trigger(event: .timer) // cannot infer contextual base in reference to member 'timer'XCTAssertEqual(stateMachine.state, .green) // type 'Equatable' has no member 'green'protocol StateMachineProtocol {
associatedtype State: Hashable
associatedtype Event: Hashable
init(state: State)
var state: State { get }
func trigger(event: Event)
func registerTransition(from: State, to: State, event: Event)
}
class StateMachine<State: Hashable, Event: Hashable> {
private var transitions: [State: [State: Event]] = [:]
private var states: Set<State> = []
private var initialState: State?
private var currentState: State {
get {
return initialState ?? states.first!
}
set {
initialState = newValue
}
}
init(state: State) {
self.initialState = state
}
func trigger(event: Event) {
guard let state = states.firstIndex(of: currentState) else {
return
}
guard let transition = transitions[currentState][state] == event else {
return
}
currentState = transition.to
}
func registerTransition(from: State, to: State, event: Event) {
guard !states.contains(to) else {
return
}
transitions[from][to] = event
}
}
class StateMachine<State: Hashable, Event: Hashable> {
private var states: Set<State> = []
private var initialState: State?
private var currentState: State {
get {
return initialState ?? states.first!
}
set {
initialState = newValue
}
}
init(state: State) {
self.initialState = state
}
func trigger(event: Event) {
guard let state = states.firstIndex(of: currentState) else {
return
}
guard let transition = states[state].firstIndex(of: event) else {
return
}
currentState = states[state][transition]
}
func registerTransition(from: State, to: State, event: Event) {
guard !states.contains(to) else {
return
}
states.insert(to)
}
}```swift
protocol StateMachineProtocol {
associatedtype State: Hashable
associatedtype Event: Hashable
init(state: State)
var state: State { get }
func trigger(event: Event)
func registerTransition(from: State, to: State, event: Event)
}
// Finite state machine with possibility to register custom transitions between states.
class StateMachine<State: Hashable, Event: Hashable> {
private var transitions: [State: [State: Event]] = [:]
private var states: Set<State> = []
private var initialState: State?
private var currentState: State {
get {
return initialState ?? states.first!
}
set {
initialState = newValue
}
}
init(state: State) {
self.initialState = state
}
func trigger(event: Event) {
guard let state = states.firstIndex(of: currentState) else {
return
}
guard let transition = transitions[currentState][state] == event else {
return
}
currentState = transition.to
}
func registerTransition(from: State, to: State, event: Event) {
guard !states.contains(to) else {
return
}
transitions[from][to] = event
}
}
```
### 解法二
```swift
class StateMachine<State: Hashable, Event: Hashable> {
private var states: Set<State> = []
private var initialState: State?
private var currentState: State {
get {
return initialState ?? states.first!
}
set {
initialState = newValue
}
}
init(state: State) {
self.initialState = state
}
func trigger(event: Event) {
guard let state = states.firstIndex(of: currentState) else {
return
}
guard let transition = states[state].firstIndex(of: event) else {
return
}
currentState = states[state][transition]
}
func registerTransition(from: State, to: State, event: Event) {
guard !states.contains(to) else {
return
}
states.insert(to)
}
}
```
### 解法三
```swift
class StateMachine<State: Hashable, Event: Hashable> {
private var states: Set<State> = []
private var initialState: State?
private var currentState: State {
get {
return initialState ?? states.first!
}
set {
initialState = newValue
}
}
init(state: State) {
self.initialState = state
}
func trigger(event: Event) {
guard let state = states.firstIndex(of: currentState) else {
return
}
guard let transition = states[state].firstIndex(of: event) else {
return
}
currentState = states[state][transition]
}
func registerTransition(from: State, to: State, event: Event) {
guard !states.contains(to) else {
return
}
states.insert(to)
}
}
```
### 解法四
```swift
class StateMachine<State: Hashable, Event: Hashable> {
private var states: Set<State> = []
private var initialState: State?
private var currentState: State {
get {
return initialState ?? states.first!
}
set {
initialState = newValue
}
}
init(state: State) {
self.initialState = state
}
func trigger(event: Event) {
guard let state = states.firstIndex(of: currentState) else {
return
}
guard let transition = states[state].firstIndex(of: event) else {
return
}
currentState = states[state][transition]
}
func registerTransition(from: State, to: State, event: Event) {
guard !states.contains(to) else {
return
}
states.insert(to)
}
}
```
### 解法五
```swift
class StateMachine<State: Hashable, Event: Hashable> {
privateguard let transition = transitions[currentState][state] == event else { // cannot convert value of type 'Set<State>.Index' to expected argument type 'State'guard let transition = transitions[currentState][state] == event else { // value of optional type '[State : Event]?' must be unwrapped to refer to member 'subscript' of wrapped base type '[State : Event]'transitions[from][to] = event // value of optional type '[State : Event]?' must be unwrapped to refer to member 'subscript' of wrapped base type '[State : Event]'class StateMachine<State: Hashable, Event: Hashable> { // invalid redeclaration of 'StateMachine'guard let transition = states[state].firstIndex(of: event) else { // value of type 'State' has no member 'firstIndex'currentState = states[state][transition] // subscript 'subscript(_:)' requires that 'Set<State>.Index' conform to 'RangeExpression'let stateMachine = StateMachine<TrafficLightState, TrafficLightEvent>(state: .green) // type 'TrafficLightEvent' has no member 'green'stateMachine.registerTransition(from: .red, to: .green, event: .timer) // cannot infer contextual base in reference to member 'green'stateMachine.registerTransition(from: .red, to: .green, event: .timer) // cannot infer contextual base in reference to member 'red'stateMachine.registerTransition(from: .red, to: .green, event: .timer) // cannot infer contextual base in reference to member 'timer'stateMachine.registerTransition(from: .green, to: .yellow, event: .timer) // cannot infer contextual base in reference to member 'green'stateMachine.registerTransition(from: .green, to: .yellow, event: .timer) // cannot infer contextual base in reference to member 'yellow'stateMachine.registerTransition(from: .green, to: .yellow, event: .timer) // cannot infer contextual base in reference to member 'timer'stateMachine.registerTransition(from: .yellow, to: .red, event: .timer) // cannot infer contextual base in reference to member 'yellow'stateMachine.registerTransition(from: .yellow, to: .red, event: .timer) // cannot infer contextual base in reference to member 'red'stateMachine.registerTransition(from: .yellow, to: .red, event: .timer) // cannot infer contextual base in reference to member 'timer'XCTAssertEqual(stateMachine.state, .green) // type 'Equatable' has no member 'green'stateMachine.trigger(event: .timer) // cannot infer contextual base in reference to member 'timer'XCTAssertEqual(stateMachine.state, .yellow) // type 'Equatable' has no member 'yellow'stateMachine.trigger(event: .timer) // cannot infer contextual base in reference to member 'timer'XCTAssertEqual(stateMachine.state, .red) // type 'Equatable' has no member 'red'stateMachine.trigger(event: .timer) // cannot infer contextual base in reference to member 'timer'XCTAssertEqual(stateMachine.state, .green) // type 'Equatable' has no member 'green'protocol StateMachineProtocol {
associatedtype State: Hashable
associatedtype Event: Hashable
init(state: State)
var state: State { get }
func trigger(event: Event)
func registerTransition(from: State, to: State, event: Event)
}
class StateMachine<State: Hashable, Event: Hashable> {
private var transitions: [State: [State: Event]] = [:]
private var states: Set<State> = []
private var currentState: State = .init()
private let initialState: State
init(state: State) {
self.initialState = state
self.currentState = state
self.states.insert(state)
}
func trigger(event: Event) {
guard let toState = transitions[currentState]?[event] else {
return
}
self.currentState = toState
}
func registerTransition(from: State, to: State, event: Event) {
guard !states.contains(to) else {
fatalError("Attempt to register transition to a state that is not registered")
}
guard !states.contains(from) else {
fatalError("Attempt to register transition from a state that is not registered")
}
guard !transitions[from]?[event] else {
fatalError("Attempt to register transition for an event that is already registered")
}
transitions[from]?[event] = to
}
}
class StateMachine<State: Hashable, Event: Hashable> {
private var states: Set<State> = []
private var events: Set<Event> = []
private var transitions: [State: [Event: State]] = [:]
private var currentState: State = .init()
init(state: State) {
self.currentState = state
self.states.insert(state)
}
func trigger(event: Event) {
guard let toState = transitions[currentState]?[event] else {
return
}
self.currentState = toState
}
func registerTransition(from: State, to: State, event: Event) {
guard !states.contains(to) else {
fatalError("Attempt to register transition to a state that is not registered")
}
guard !states.contains(from) else {
fatalError("Attempt to register transition from a state that is not registered")
}
guard !events.contains(event) else {
fatalError("Attempt to register transition for an event that is already registered")
}
transitions[from]?[event] = to
}
}
class StateMachine<State: Hashable, Event: Hashable> {
private var states: Set<State> = []
private var events: Set<Event> = []
private var transitions: [State: [Event: State]] = [:]
private var currentState: State = .init()
func trigger(event: Event) {
guard let toState = transitions[currentState]?[event] else {
return
}
self.currentState = toState
}
func registerTransition(from: State, to: State, event: Event) {
guard !states.contains(to) else {
fatalError("Attempt to register transition to a state that is not registered")
}
guard !states.contains(from) else {
fatalError("Attempt to register transition from a state that is not registered")
}
guard !events.contains(event) else {
fatalError("Attempt to register transition for an event that is already registered")
}
transitions[from]?[event] = to
}
}```swift
protocol StateMachineProtocol {
associatedtype State: Hashable
associatedtype Event: Hashable
init(state: State)
var state: State { get }
func trigger(event: Event)
func registerTransition(from: State, to: State, event: Event)
}
// Finite state machine with possibility to register custom transitions between states.
class StateMachine<State: Hashable, Event: Hashable> {
private var transitions: [State: [State: Event]] = [:]
private var states: Set<State> = []
private var currentState: State = .init()
private let initialState: State
init(state: State) {
self.initialState = state
self.currentState = state
self.states.insert(state)
}
func trigger(event: Event) {
guard let toState = transitions[currentState]?[event] else {
return
}
self.currentState = toState
}
func registerTransition(from: State, to: State, event: Event) {
guard !states.contains(to) else {
fatalError("Attempt to register transition to a state that is not registered")
}
guard !states.contains(from) else {
fatalError("Attempt to register transition from a state that is not registered")
}
guard !transitions[from]?[event] else {
fatalError("Attempt to register transition for an event that is already registered")
}
transitions[from]?[event] = to
}
}
```
### 解法二
```swift
class StateMachine<State: Hashable, Event: Hashable> {
private var states: Set<State> = []
private var events: Set<Event> = []
private var transitions: [State: [Event: State]] = [:]
private var currentState: State = .init()
init(state: State) {
self.currentState = state
self.states.insert(state)
}
func trigger(event: Event) {
guard let toState = transitions[currentState]?[event] else {
return
}
self.currentState = toState
}
func registerTransition(from: State, to: State, event: Event) {
guard !states.contains(to) else {
fatalError("Attempt to register transition to a state that is not registered")
}
guard !states.contains(from) else {
fatalError("Attempt to register transition from a state that is not registered")
}
guard !events.contains(event) else {
fatalError("Attempt to register transition for an event that is already registered")
}
transitions[from]?[event] = to
}
}
```
### 解法三
```swift
class StateMachine<State: Hashable, Event: Hashable> {
private var states: Set<State> = []
private var events: Set<Event> = []
private var transitions: [State: [Event: State]] = [:]
private var currentState: State = .init()
func trigger(event: Event) {
guard let toState = transitions[currentState]?[event] else {
return
}
self.currentState = toState
}
func registerTransition(from: State, to: State, event: Event) {
guard !states.contains(to) else {
fatalError("Attempt to register transition to a state that is not registered")
}
guard !states.contains(from) else {
fatalError("Attempt to register transition from a state that is not registered")
}
guard !events.contains(event) else {
fatalError("Attempt to register transition for an event that is already registered")
}
transitions[from]?[event] = to
}
}
```private var currentState: State = .init() // type 'State' has no member 'init'guard let toState = transitions[currentState]?[event] else { // subscript 'subscript(_:)' requires that 'Event' conform to 'RangeExpression'guard !transitions[from]?[event] else { // subscript 'subscript(_:)' requires that 'Event' conform to 'RangeExpression'guard !transitions[from]?[event] else { // optional type 'Dictionary<State, Event>.SubSequence?' (aka 'Optional<Slice<Dictionary<State, Event>>>') cannot be used as a boolean; test for '== nil' insteadtransitions[from]?[event] = to // cannot convert value of type 'Event' to expected argument type 'State'transitions[from]?[event] = to // cannot assign value of type 'State' to subscript of type 'Event'class StateMachine<State: Hashable, Event: Hashable> { // invalid redeclaration of 'StateMachine'private var currentState: State = .init() // type 'State' has no member 'init'class StateMachine<State: Hashable, Event: Hashable> { // invalid redeclaration of 'StateMachine'private var currentState: State = .init() // type 'State' has no member 'init'let stateMachine = StateMachine<TrafficLightState, TrafficLightEvent>(state: .green) // type 'TrafficLightEvent' has no member 'green'stateMachine.registerTransition(from: .red, to: .green, event: .timer) // cannot infer contextual base in reference to member 'red'stateMachine.registerTransition(from: .red, to: .green, event: .timer) // cannot infer contextual base in reference to member 'green'stateMachine.registerTransition(from: .red, to: .green, event: .timer) // cannot infer contextual base in reference to member 'timer'stateMachine.registerTransition(from: .green, to: .yellow, event: .timer) // cannot infer contextual base in reference to member 'yellow'stateMachine.registerTransition(from: .green, to: .yellow, event: .timer) // cannot infer contextual base in reference to member 'green'stateMachine.registerTransition(from: .green, to: .yellow, event: .timer) // cannot infer contextual base in reference to member 'timer'stateMachine.registerTransition(from: .yellow, to: .red, event: .timer) // cannot infer contextual base in reference to member 'yellow'stateMachine.registerTransition(from: .yellow, to: .red, event: .timer) // cannot infer contextual base in reference to member 'red'stateMachine.registerTransition(from: .yellow, to: .red, event: .timer) // cannot infer contextual base in reference to member 'timer'XCTAssertEqual(stateMachine.state, .green) // type 'Equatable' has no member 'green'stateMachine.trigger(event: .timer) // cannot infer contextual base in reference to member 'timer'XCTAssertEqual(stateMachine.state, .yellow) // type 'Equatable' has no member 'yellow'stateMachine.trigger(event: .timer) // cannot infer contextual base in reference to member 'timer'XCTAssertEqual(stateMachine.state, .red) // type 'Equatable' has no member 'red'stateMachine.trigger(event: .timer) // cannot infer contextual base in reference to member 'timer'XCTAssertEqual(stateMachine.state, .green) // type 'Equatable' has no member 'green'protocol StateMachineProtocol {
associatedtype State: Hashable
associatedtype Event: Hashable
init(state: State)
var state: State { get }
func trigger(event: Event)
func registerTransition(from: State, to: State, event: Event)
}
class StateMachine<State: Hashable, Event: Hashable> {
private var states: [State: Set<Event>] = [:]
private var transitions: [State: [State: Set<Event>]] = [:]
private var initialState: State
init(state: State) {
initialState = state
}
func trigger(event: Event) {
guard let state = states[initialState]?.intersection(transitions[initialState]![initialState]!).first else {
return
}
let nextState = state.intersection(transitions[initialState]![state]!).first
if let nextState = nextState {
initialState = nextState
}
}
func registerTransition(from: State, to: State, event: Event) {
states[from, default: []].insert(event)
transitions[from, default: [:]][to, default: []].insert(event)
}
}```swift
protocol StateMachineProtocol {
associatedtype State: Hashable
associatedtype Event: Hashable
init(state: State)
var state: State { get }
func trigger(event: Event)
func registerTransition(from: State, to: State, event: Event)
}
// Finite state machine with possibility to register custom transitions between states.
class StateMachine<State: Hashable, Event: Hashable> {
private var states: [State: Set<Event>] = [:]
private var transitions: [State: [State: Set<Event>]] = [:]
private var initialState: State
init(state: State) {
initialState = state
}
func trigger(event: Event) {
guard let state = states[initialState]?.intersection(transitions[initialState]![initialState]!).first else {
return
}
let nextState = state.intersection(transitions[initialState]![state]!).first
if let nextState = nextState {
initialState = nextState
}
}
func registerTransition(from: State, to: State, event: Event) {
states[from, default: []].insert(event)
transitions[from, default: [:]][to, default: []].insert(event)
}
}
```
### 解法二
```swift
class StateMachine<State: Hashable, Event: Hashable> {
private var states: [State: Set<Event>] = [:]
private var transitions: [State: [State: Set<Event>]] = [:]
private var initialState: State
init(state: State) {
initialState = state
}
func trigger(event: Event) {
guard let state = states[initialState]?.intersection(transitions[initialState]![initialState]!).first else {
return
}
let nextState = state.intersection(transitions[initialState]![state]!).first
if let nextState = nextState {
initialState = nextState
}
}
func registerTransition(from: State, to: State, event: Event) {
states[from, default: []].insert(event)
transitions[from, default: [:]][to, default: []].insert(event)
}
}
```let nextState = state.intersection(transitions[initialState]![state]!).first // cannot convert value of type 'Event' to expected argument type 'State'let nextState = state.intersection(transitions[initialState]![state]!).first // value of type 'Event' has no member 'intersection'XCTAssertEqual(stateMachine.state, .green) // value of type 'StateMachine<TrafficLightState, TrafficLightEvent>' has no member 'state'XCTAssertEqual(stateMachine.state, .green) // type 'Equatable' has no member 'green'XCTAssertEqual(stateMachine.state, .yellow) // type 'Equatable' has no member 'yellow'XCTAssertEqual(stateMachine.state, .yellow) // value of type 'StateMachine<TrafficLightState, TrafficLightEvent>' has no member 'state'XCTAssertEqual(stateMachine.state, .red) // type 'Equatable' has no member 'red'XCTAssertEqual(stateMachine.state, .red) // value of type 'StateMachine<TrafficLightState, TrafficLightEvent>' has no member 'state'XCTAssertEqual(stateMachine.state, .green) // type 'Equatable' has no member 'green'XCTAssertEqual(stateMachine.state, .green) // value of type 'StateMachine<TrafficLightState, TrafficLightEvent>' has no member 'state'indirect enum FileSystemNode {
case file(name: String, size: Int)
case directory(name: String, contents: [FileSystemNode])
}
protocol FileSystemInfo {
var totalSize: Int { get }
var filesCount: Int { get }
var treeDepth: Int { get }
}
extension FileSystemNode: FileSystemInfo {
var totalSize: Int {
switch self {
case .file(let name, let size):
return size
case .directory(let name, let contents):
return contents.reduce(0) { $0 + $1.totalSize }
}
}
var filesCount: Int {
switch self {
case .file(let name, let size):
return 1
case .directory(let name, let contents):
return contents.reduce(0) { $0 + $1.filesCount }
}
}
var treeDepth: Int {
switch self {
case .file(let name, let size):
return 1
case .directory(let name, let contents):
return contents.reduce(0) { $0 > $1.treeDepth ? $0 : $1.treeDepth } + 1
}
}
}
class FileSystemManager {
private let root: FileSystemNode
init(root: FileSystemNode) {
self.root = root
}
func getInfo() -> FileSystemInfo {
return FileSystemInfo(root: root)
}
}```swift
indirect enum FileSystemNode {
case file(name: String, size: Int)
case directory(name: String, contents: [FileSystemNode])
}
protocol FileSystemInfo {
var totalSize: Int { get }
var filesCount: Int { get }
var treeDepth: Int { get }
}
// Abstract file system manager and metadata calculation.
// Used to calculate total size of all files in file system, files count and file system tree depth.
extension FileSystemNode: FileSystemInfo {
var totalSize: Int {
switch self {
case .file(let name, let size):
return size
case .directory(let name, let contents):
return contents.reduce(0) { $0 + $1.totalSize }
}
}
var filesCount: Int {
switch self {
case .file(let name, let size):
return 1
case .directory(let name, let contents):
return contents.reduce(0) { $0 + $1.filesCount }
}
}
var treeDepth: Int {
switch self {
case .file(let name, let size):
return 1
case .directory(let name, let contents):
return contents.reduce(0) { $0 > $1.treeDepth ? $0 : $1.treeDepth } + 1
}
}
}
// Concrete file system manager.
class FileSystemManager {
private let root: FileSystemNode
init(root: FileSystemNode) {
self.root = root
}
func getInfo() -> FileSystemInfo {
return FileSystemInfo(root: root)
}
}
// Concrete file system manager.
class FileSystemManager {
private let root: FileSystemNode
init(root: FileSystemNode) {
self.root = root
}
func getInfo() -> FileSystemInfo {
return FileSystemInfo(root: root)
}
}
// Concrete file system manager.
class FileSystemManager {
private let root: FileSystemNode
init(root: FileSystemNode) {
self.root = root
}
func getInfo() -> FileSystemInfo {
return FileSystemInfo(root: root)
}
}
// Concrete file system manager.
class FileSystemManager {
private let root: FileSystemNode
init(root: FileSystemNode) {
self.root = root
}
func getInfo() -> FileSystemInfo {
return FileSystemInfo(root: root)
}
}
// Concrete file system manager.
class FileSystemManager {
private let root: FileSystemNode
init(root: FileSystemNode) {
self.root = root
}
func getInfo() -> FileSystemInfo {
return FileSystemInfo(root: root)
}
}
// Concrete file system manager.
class FileSystemManager {
private let root: FileSystemNode
init(root: FileSystemNode) {
self.root = root
}
func getInfo() -> FileSystemInfo {
return FileSystemInfo(root: root)
}
}
// Concrete file system manager.
class FileSystemManager {
private let root: FileSystemNode
init(root: FileSystemNode) {
self.root = root
}
func getInfo() -> FileSystemInfo {
return FileSystemInfo(root: root)
}
}
// Concrete file system manager.
class FileSystemManager {
private let root: FileSystemNode
init(root: FileSystemNode) {
self.root = root
}
func getInfo() -> FileSystemInfo {
return FileSystemInfo(root: root)
}
}
// Concrete file system manager.
class FileSystemManager {
private let root: FileSystemNode
init(root: FileSystemNode) {
self.root = root
}
func getInfo() -> FileSystemInfo {
return FileSystemInfo(root: root)
}
}
// Concrete file system manager.
class FileSystemManager {
private let root: FileSystemNode
init(root: FileSystemNode) {
self.root = root
}
func getInfo() -> FileSystemInfo {
return FileSystemInfo(root: root)
}
}
// Concrete file system manager.
class FileSystemManager {
private let root: FileSystemNode
init(root: FileSystemNode) {
selfcase .file(let name, let size): // immutable value 'name' was never used; consider replacing with '_' or removing itcase .directory(let name, let contents): // immutable value 'name' was never used; consider replacing with '_' or removing itcase .file(let name, let size): // immutable value 'size' was never used; consider replacing with '_' or removing itcase .file(let name, let size): // immutable value 'name' was never used; consider replacing with '_' or removing itcase .directory(let name, let contents): // immutable value 'name' was never used; consider replacing with '_' or removing itcase .file(let name, let size): // immutable value 'name' was never used; consider replacing with '_' or removing itcase .file(let name, let size): // immutable value 'size' was never used; consider replacing with '_' or removing itcase .directory(let name, let contents): // immutable value 'name' was never used; consider replacing with '_' or removing itreturn FileSystemInfo(root: root) // 'any FileSystemInfo' cannot be constructed because it has no accessible initializersindirect enum FileSystemNode {
case file(name: String, size: Int)
case directory(name: String, contents: [FileSystemNode])
}
protocol FileSystemInfo {
var totalSize: Int { get }
var filesCount: Int { get }
var treeDepth: Int { get }
}
extension FileSystemNode: FileSystemInfo {
var totalSize: Int {
switch self {
case .file(let name, let size):
return size
case .directory(let name, let contents):
return contents.reduce(0) { $0 + $1.totalSize }
}
}
var filesCount: Int {
switch self {
case .file(let name, let size):
return 1
case .directory(let name, let contents):
return contents.reduce(0) { $0 + $1.filesCount }
}
}
var treeDepth: Int {
switch self {
case .file(let name, let size):
return 1
case .directory(let name, let contents):
return contents.reduce(0) { $0 > $1.treeDepth ? $0 : $1.treeDepth } + 1
}
}
}
extension FileSystemNode {
static func createFile(at path: String, withSize size: Int) -> FileSystemNode {
return .file(name: path, size: size)
}
static func createDirectory(at path: String, withContents contents: [FileSystemNode]) -> FileSystemNode {
return .directory(name: path, contents: contents)
}
}
class FileSystemManager {
private let root: FileSystemNode
init(root: FileSystemNode) {
self.root = root
}
func totalSize() -> Int {
return root.totalSize
}
func filesCount() -> Int {
return root.filesCount
}
func treeDepth() -> Int {
return root.treeDepth
}
}
class FileSystemInfo {
private let manager: FileSystemManager
init(manager: FileSystemManager) {
self.manager = manager
}
func totalSize() -> Int {
return manager.totalSize()
}
func filesCount() -> Int {
return manager.filesCount()
}
func treeDepth() -> Int {
return manager.treeDepth()
}
}
class FileSystemInfoFactory {
private let manager: FileSystemManager
init(manager: FileSystemManager) {
self.manager = manager
}
func create() -> FileSystemInfo {
return FileSystemInfo(manager: manager)
}
}```swift
indirect enum FileSystemNode {
case file(name: String, size: Int)
case directory(name: String, contents: [FileSystemNode])
}
protocol FileSystemInfo {
var totalSize: Int { get }
var filesCount: Int { get }
var treeDepth: Int { get }
}
// Abstract file system manager and metadata calculation.
// Used to calculate total size of all files in file system, files count and file system tree depth.
extension FileSystemNode: FileSystemInfo {
var totalSize: Int {
switch self {
case .file(let name, let size):
return size
case .directory(let name, let contents):
return contents.reduce(0) { $0 + $1.totalSize }
}
}
var filesCount: Int {
switch self {
case .file(let name, let size):
return 1
case .directory(let name, let contents):
return contents.reduce(0) { $0 + $1.filesCount }
}
}
var treeDepth: Int {
switch self {
case .file(let name, let size):
return 1
case .directory(let name, let contents):
return contents.reduce(0) { $0 > $1.treeDepth ? $0 : $1.treeDepth } + 1
}
}
}
// Concrete file system manager and metadata calculation.
// Used to calculate total size of all files in file system, files count and file system tree depth.
extension FileSystemNode {
static func createFile(at path: String, withSize size: Int) -> FileSystemNode {
return .file(name: path, size: size)
}
static func createDirectory(at path: String, withContents contents: [FileSystemNode]) -> FileSystemNode {
return .directory(name: path, contents: contents)
}
}
// File system manager and metadata calculation.
// Used to calculate total size of all files in file system, files count and file system tree depth.
class FileSystemManager {
private let root: FileSystemNode
init(root: FileSystemNode) {
self.root = root
}
func totalSize() -> Int {
return root.totalSize
}
func filesCount() -> Int {
return root.filesCount
}
func treeDepth() -> Int {
return root.treeDepth
}
}
// File system metadata calculation.
// Used to calculate total size of all files in file system, files count and file system tree depth.
class FileSystemInfo {
private let manager: FileSystemManager
init(manager: FileSystemManager) {
self.manager = manager
}
func totalSize() -> Int {
return manager.totalSize()
}
func filesCount() -> Int {
return manager.filesCount()
}
func treeDepth() -> Int {
return manager.treeDepth()
}
}
// File system metadata calculation.
// Used to calculate total size of all files in file system, files count and file system tree depth.
class FileSystemInfoFactory {
private let manager: FileSystemManager
init(manager: FileSystemManager) {
self.manager = manager
}
func create() -> FileSystemInfo {
return FileSystemInfo(manager: manager)
}
}
// File system metadata calculation.
// Used to calculate total size of all files in file system, files count and file system tree depth.
class FileSystemInfoFactory {
private let manager: FileSystemManager
init(manager: FileSystemManager) {
self.manager = manager
}
func create() -> FileSystemInfo {
return FileSystemInfo(manager: manager)
}
}
// File system metadata calculation.
// Used to calculate total size of all files in file system, files count and file system tree depth.
class FileSystemInfoFactory {
private let manager: FileSystemManager
init(manager: FileSystemManager) {
self.manager = manager
}
func create() -> FileSystemInfo {
return FileSystemInfo(manager: manager)
}
}
// File system metadata calculation.
// Used to calculate total size of all files in file system, files count and file system tree depth.
class FileSystemInfoFactory {
private let manager: FileSystemManager
init(manager: FileSystemManager) {
self.manager = manager
}
func create() -> FileSystemInfo {
return FileSystemInfo(manager: manager)
}
}
// File system metadata calculation.extension FileSystemNode: FileSystemInfo { // 'FileSystemInfo' is ambiguous for type lookup in this contextcase .file(let name, let size): // immutable value 'name' was never used; consider replacing with '_' or removing itcase .directory(let name, let contents): // immutable value 'name' was never used; consider replacing with '_' or removing itcase .file(let name, let size): // immutable value 'size' was never used; consider replacing with '_' or removing itcase .file(let name, let size): // immutable value 'name' was never used; consider replacing with '_' or removing itcase .directory(let name, let contents): // immutable value 'name' was never used; consider replacing with '_' or removing itcase .file(let name, let size): // immutable value 'name' was never used; consider replacing with '_' or removing itcase .file(let name, let size): // immutable value 'size' was never used; consider replacing with '_' or removing itcase .directory(let name, let contents): // immutable value 'name' was never used; consider replacing with '_' or removing itclass FileSystemInfo { // invalid redeclaration of 'FileSystemInfo'func create() -> FileSystemInfo { // 'FileSystemInfo' is ambiguous for type lookup in this contextindirect enum FileSystemNode {
case file(name: String, size: Int)
case directory(name: String, contents: [FileSystemNode])
}
protocol FileSystemInfo {
var totalSize: Int { get }
var filesCount: Int { get }
var treeDepth: Int { get }
}
extension FileSystemNode: FileSystemInfo {
var totalSize: Int {
switch self {
case .file(let name, let size):
return size
case .directory(let name, let contents):
return contents.reduce(0) { $0 + $1.totalSize }
}
}
var filesCount: Int {
switch self {
case .file(let name, let size):
return 1
case .directory(let name, let contents):
return contents.reduce(0) { $0 + $1.filesCount }
}
}
var treeDepth: Int {
switch self {
case .file(let name, let size):
return 1
case .directory(let name, let contents):
return contents.reduce(0) { $0 > $1.treeDepth ? $0 : $1.treeDepth } + 1
}
}
}
class FileSystemManager {
let root: FileSystemNode
init(_ root: FileSystemNode) {
self.root = root
}
func getInfo() -> FileSystemInfo {
return FileSystemInfo(root: root)
}
}
protocol FileSystemNode {
func getInfo() -> FileSystemInfo
}
extension FileSystemNode {
func getInfo() -> FileSystemInfo {
return FileSystemManager(self).getInfo()
}
}
extension FileSystemNode {
func add(file: String, size: Int) -> FileSystemNode {
return .file(name: file, size: size)
}
func add(directory: String, contents: [FileSystemNode]) -> FileSystemNode {
return .directory(name: directory, contents: contents)
}
}```swift
indirect enum FileSystemNode {
case file(name: String, size: Int)
case directory(name: String, contents: [FileSystemNode])
}
protocol FileSystemInfo {
var totalSize: Int { get }
var filesCount: Int { get }
var treeDepth: Int { get }
}
// Abstract file system manager and metadata calculation.
// Used to calculate total size of all files in file system, files count and file system tree depth.
extension FileSystemNode: FileSystemInfo {
var totalSize: Int {
switch self {
case .file(let name, let size):
return size
case .directory(let name, let contents):
return contents.reduce(0) { $0 + $1.totalSize }
}
}
var filesCount: Int {
switch self {
case .file(let name, let size):
return 1
case .directory(let name, let contents):
return contents.reduce(0) { $0 + $1.filesCount }
}
}
var treeDepth: Int {
switch self {
case .file(let name, let size):
return 1
case .directory(let name, let contents):
return contents.reduce(0) { $0 > $1.treeDepth ? $0 : $1.treeDepth } + 1
}
}
}
// Concrete file system manager and metadata calculation.
// Used to calculate total size of all files in file system, files count and file system tree depth.
class FileSystemManager {
let root: FileSystemNode
init(_ root: FileSystemNode) {
self.root = root
}
func getInfo() -> FileSystemInfo {
return FileSystemInfo(root: root)
}
}
// Protocol for file system nodes.
// Used to calculate total size of all files in file system, files count and file system tree depth.
protocol FileSystemNode {
func getInfo() -> FileSystemInfo
}
// Protocol for file system nodes.
// Used to calculate total size of all files in file system, files count and file system tree depth.
extension FileSystemNode {
func getInfo() -> FileSystemInfo {
return FileSystemManager(self).getInfo()
}
}
// Protocol for file system nodes.
// Used to calculate total size of all files in file system, files count and file system tree depth.
extension FileSystemNode {
func add(file: String, size: Int) -> FileSystemNode {
return .file(name: file, size: size)
}
func add(directory: String, contents: [FileSystemNode]) -> FileSystemNode {
return .directory(name: directory, contents: contents)
}
}
// Protocol for file system nodes.
// Used to calculate total size of all files in file system, files count and file system tree depth.
extension FileSystemNode {
func add(file: String, size: Int) -> FileSystemNode {
return .file(name: file, size: size)
}
func add(directory: String, contents: [FileSystemNode]) -> FileSystemNode {
return .directory(name: directory, contents: contents)
}
}
// Protocol for file system nodes.
// Used to calculate total size of all files in file system, files count and file system tree depth.
extension FileSystemNode {
func add(file: String, size: Int) -> FileSystemNode {
return .file(name: file, size: size)
}
func add(directory: String, contents: [FileSystemNode]) -> FileSystemNode {
return .directory(name: directory, contents: contents)
}
}
// Protocol for file system nodes.
// Used to calculate total size of all files in file system, files count and file system tree depth.
extension FileSystemNode {
func add(file: String, size: Int) -> FileSystemNode {
return .file(name: file, size: size)
}
func add(directory: String, contents: [FileSystemNode]) -> FileSystemNode {
return .directory(name: directory, contents: contents)
}
}
// Protocol for file system nodes.
// Used to calculate total size of all files in file system, files count and file system tree depth.
extension FileSystemNode {
func add(file: String, size: Int) -> FileSystemNode {
return .file(name: file, size: size)
}
func add(directory: String, contents: [FileSystemNode]) -> FileSystemNode {
return .directory(name: directory, contents: contents)
}
}
// Protocol for file system nodes.case directory(name: String, contents: [FileSystemNode]) // 'FileSystemNode' is ambiguous for type lookup in this contextextension FileSystemNode: FileSystemInfo { // 'FileSystemNode' is ambiguous for type lookup in this contextlet root: FileSystemNode // 'FileSystemNode' is ambiguous for type lookup in this contextinit(_ root: FileSystemNode) { // 'FileSystemNode' is ambiguous for type lookup in this contextreturn FileSystemInfo(root: root) // 'any FileSystemInfo' cannot be constructed because it has no accessible initializersprotocol FileSystemNode { // invalid redeclaration of 'FileSystemNode'extension FileSystemNode { // 'FileSystemNode' is ambiguous for type lookup in this contextextension FileSystemNode { // 'FileSystemNode' is ambiguous for type lookup in this contextXCTAssertEqual(file.totalSize, 100) // value of type 'FileSystemNode' has no member 'totalSize'indirect enum FileSystemNode {
case file(name: String, size: Int)
case directory(name: String, contents: [FileSystemNode])
}
protocol FileSystemInfo {
var totalSize: Int { get }
var filesCount: Int { get }
var treeDepth: Int { get }
}
extension FileSystemNode: FileSystemInfo {
var totalSize: Int {
switch self {
case let .file(_, size):
return size
case let .directory(_, contents):
return contents.reduce(0) { $0 + $1.totalSize }
}
}
var filesCount: Int {
switch self {
case let .file(_):
return 1
case let .directory(_, contents):
return contents.reduce(0) { $0 + $1.filesCount }
}
}
var treeDepth: Int {
switch self {
case let .file(_):
return 0
case let .directory(_, contents):
return contents.reduce(0) { $0 > $1.treeDepth ? $0 : $1.treeDepth } + 1
}
}
}
class FileSystemManager {
private let root: FileSystemNode
init(root: FileSystemNode) {
self.root = root
}
func getInfo() -> FileSystemInfo {
return FileSystemInfo(root: root)
}
}
class FileSystemInfo {
private let root: FileSystemNode
init(root: FileSystemNode) {
self.root = root
}
func getInfo() -> FileSystemInfo {
return self
}
}
class FileSystemNode {
private let name: String
private let size: Int
private let contents: [FileSystemNode]
init(name: String, size: Int, contents: [FileSystemNode]) {
self.name = name
self.size = size
self.contents = contents
}
func getInfo() -> FileSystemInfo {
return FileSystemInfo(root: self)
}
}```swift
indirect enum FileSystemNode {
case file(name: String, size: Int)
case directory(name: String, contents: [FileSystemNode])
}
protocol FileSystemInfo {
var totalSize: Int { get }
var filesCount: Int { get }
var treeDepth: Int { get }
}
// Abstract file system manager and metadata calculation.
// Used to calculate total size of all files in file system, files count and file system tree depth.
extension FileSystemNode: FileSystemInfo {
var totalSize: Int {
switch self {
case let .file(_, size):
return size
case let .directory(_, contents):
return contents.reduce(0) { $0 + $1.totalSize }
}
}
var filesCount: Int {
switch self {
case let .file(_):
return 1
case let .directory(_, contents):
return contents.reduce(0) { $0 + $1.filesCount }
}
}
var treeDepth: Int {
switch self {
case let .file(_):
return 0
case let .directory(_, contents):
return contents.reduce(0) { $0 > $1.treeDepth ? $0 : $1.treeDepth } + 1
}
}
}
// Concrete file system manager and metadata calculation.
class FileSystemManager {
private let root: FileSystemNode
init(root: FileSystemNode) {
self.root = root
}
func getInfo() -> FileSystemInfo {
return FileSystemInfo(root: root)
}
}
// Concrete file system manager and metadata calculation.
class FileSystemInfo {
private let root: FileSystemNode
init(root: FileSystemNode) {
self.root = root
}
func getInfo() -> FileSystemInfo {
return self
}
}
// Concrete file system manager and metadata calculation.
class FileSystemNode {
private let name: String
private let size: Int
private let contents: [FileSystemNode]
init(name: String, size: Int, contents: [FileSystemNode]) {
self.name = name
self.size = size
self.contents = contents
}
func getInfo() -> FileSystemInfo {
return FileSystemInfo(root: self)
}
}
// Concrete file system manager and metadata calculation.
class FileSystemNode {
private let name: String
private let size: Int
private let contents: [FileSystemNode]
init(name: String, size: Int, contents: [FileSystemNode]) {
self.name = name
self.size = size
self.contents = contents
}
func getInfo() -> FileSystemInfo {
return FileSystemInfo(root: self)
}
}
// Concrete file system manager and metadata calculation.
class FileSystemNode {
private let name: String
private let size: Int
private let contents: [FileSystemNode]
init(name: String, size: Int, contents: [FileSystemNode]) {
self.name = name
self.size = size
self.contents = contents
}
func getInfo() -> FileSystemInfo {
return FileSystemInfo(root: self)
}
}
// Concrete file system manager and metadata calculation.
class FileSystemNode {
private let name: String
private let size: Int
private let contents: [FileSystemNode]
init(name: String, size: Int, contents: [FileSystemNode]) {
self.name = name
self.size = size
self.contents = contents
}
func getInfo() -> FileSystemInfo {
return FileSystemInfo(root: self)
}
}
// Concrete file system manager and metadata calculation.
class FileSystemNode {
private let name: String
private let size: Int
private let contents: [FileSystemNode]
init(name: String, size: Int, contents: [FileSystemNode]) {
self.name = name
self.size = size
self.contents = contents
}
func getInfo() -> FileSystemInfo {
return FileSystemInfo(root: self)
}
}
// Concrete file system manager and metadata calculation.
class FileSystemNode {
private let name: String
private let size: Int
private let contents: [FileSystemNode]
init(name: String, sizecase directory(name: String, contents: [FileSystemNode]) // 'FileSystemNode' is ambiguous for type lookup in this contextextension FileSystemNode: FileSystemInfo { // 'FileSystemNode' is ambiguous for type lookup in this contextprivate let root: FileSystemNode // 'FileSystemNode' is ambiguous for type lookup in this contextinit(root: FileSystemNode) { // 'FileSystemNode' is ambiguous for type lookup in this contextfunc getInfo() -> FileSystemInfo { // 'FileSystemInfo' is ambiguous for type lookup in this contextclass FileSystemInfo { // invalid redeclaration of 'FileSystemInfo'private let root: FileSystemNode // 'FileSystemNode' is ambiguous for type lookup in this contextinit(root: FileSystemNode) { // 'FileSystemNode' is ambiguous for type lookup in this contextfunc getInfo() -> FileSystemInfo { // 'FileSystemInfo' is ambiguous for type lookup in this contextclass FileSystemNode { // invalid redeclaration of 'FileSystemNode'private let contents: [FileSystemNode] // 'FileSystemNode' is ambiguous for type lookup in this contextinit(name: String, size: Int, contents: [FileSystemNode]) { // 'FileSystemNode' is ambiguous for type lookup in this contextfunc getInfo() -> FileSystemInfo { // 'FileSystemInfo' is ambiguous for type lookup in this contextXCTAssertEqual(file.totalSize, 100) // value of type 'FileSystemNode' has no member 'totalSize'indirect enum FileSystemNode {
case file(name: String, size: Int)
case directory(name: String, contents: [FileSystemNode])
}
protocol FileSystemInfo {
var totalSize: Int { get }
var filesCount: Int { get }
var treeDepth: Int { get }
}
extension FileSystemNode: FileSystemInfo {
var totalSize: Int {
switch self {
case .file(let name, let size):
return size
case .directory(let name, let contents):
return contents.reduce(0) { $0 + $1.totalSize }
}
}
var filesCount: Int {
switch self {
case .file(let name, let size):
return 1
case .directory(let name, let contents):
return contents.reduce(0) { $0 + $1.filesCount }
}
}
var treeDepth: Int {
switch self {
case .file(let name, let size):
return 1
case .directory(let name, let contents):
return contents.reduce(0) { $0 > $1.treeDepth ? $0 : $1.treeDepth } + 1
}
}
}
class FileSystemManager {
let root: FileSystemNode
init(root: FileSystemNode) {
self.root = root
}
func getInfo() -> FileSystemInfo {
return FileSystemInfo(root: root)
}
}
class FileSystemInfo {
let root: FileSystemNode
init(root: FileSystemNode) {
self.root = root
}
func getInfo() -> FileSystemInfo {
return FileSystemInfo(root: root)
}
}```swift
indirect enum FileSystemNode {
case file(name: String, size: Int)
case directory(name: String, contents: [FileSystemNode])
}
protocol FileSystemInfo {
var totalSize: Int { get }
var filesCount: Int { get }
var treeDepth: Int { get }
}
// Abstract file system manager and metadata calculation.
// Used to calculate total size of all files in file system, files count and file system tree depth.
extension FileSystemNode: FileSystemInfo {
var totalSize: Int {
switch self {
case .file(let name, let size):
return size
case .directory(let name, let contents):
return contents.reduce(0) { $0 + $1.totalSize }
}
}
var filesCount: Int {
switch self {
case .file(let name, let size):
return 1
case .directory(let name, let contents):
return contents.reduce(0) { $0 + $1.filesCount }
}
}
var treeDepth: Int {
switch self {
case .file(let name, let size):
return 1
case .directory(let name, let contents):
return contents.reduce(0) { $0 > $1.treeDepth ? $0 : $1.treeDepth } + 1
}
}
}
// Concrete file system manager and metadata calculation.
// Used to calculate total size of all files in file system, files count and file system tree depth.
class FileSystemManager {
let root: FileSystemNode
init(root: FileSystemNode) {
self.root = root
}
func getInfo() -> FileSystemInfo {
return FileSystemInfo(root: root)
}
}
// Concrete file system manager and metadata calculation.
// Used to calculate total size of all files in file system, files count and file system tree depth.
class FileSystemInfo {
let root: FileSystemNode
init(root: FileSystemNode) {
self.root = root
}
func getInfo() -> FileSystemInfo {
return FileSystemInfo(root: root)
}
}
// Concrete file system manager and metadata calculation.
// Used to calculate total size of all files in file system, files count and file system tree depth.
class FileSystemInfo {
let root: FileSystemNode
init(root: FileSystemNode) {
self.root = root
}
func getInfo() -> FileSystemInfo {
return FileSystemInfo(root: root)
}
}
// Concrete file system manager and metadata calculation.
// Used to calculate total size of all files in file system, files count and file system tree depth.
class FileSystemInfo {
let root: FileSystemNode
init(root: FileSystemNode) {
self.root = root
}
func getInfo() -> FileSystemInfo {
return FileSystemInfo(root: root)
}
}
// Concrete file system manager and metadata calculation.
// Used to calculate total size of all files in file system, files count and file system tree depth.
class FileSystemInfo {
let root: FileSystemNode
init(root: FileSystemNode) {
self.root = root
}
func getInfo() -> FileSystemInfo {
return FileSystemInfo(root: root)
}
}
// Concrete file system manager and metadata calculation.
// Used to calculate total size of all files in file system, files count and file system tree depth.
class FileSystemInfo {
let root: FileSystemNode
init(root: FileSystemNode) {
self.root = root
}
func getInfo() -> FileSystemInfo {
return FileSystemInfo(root: root)
}
}
// Concrete file system manager and metadata calculation.
// Used to calculate total size of all files in file system, files count and file system tree depth.
class FileSystemInfo {
let root: FileSystemNode
init(root: FileSystemNode) {
self.root = root
}
func getInfo() -> FileSystemInfo {
return FileSystemInfo(root: root)
}
}
// Concrete file system manager and metadata calculation.
// Used to calculate total size of all files in file system, files count and file system tree depth.
class FileSystemInfo {
let root: FileSystemNode
init(root: FileSystemNode) {
self.root = root
}
func getInfo() -> FileSystemInfo {
return FileSystemInfo(root: root)
}
}extension FileSystemNode: FileSystemInfo { // 'FileSystemInfo' is ambiguous for type lookup in this contextcase .file(let name, let size): // immutable value 'name' was never used; consider replacing with '_' or removing itcase .directory(let name, let contents): // immutable value 'name' was never used; consider replacing with '_' or removing itcase .file(let name, let size): // immutable value 'size' was never used; consider replacing with '_' or removing itcase .file(let name, let size): // immutable value 'name' was never used; consider replacing with '_' or removing itcase .directory(let name, let contents): // immutable value 'name' was never used; consider replacing with '_' or removing itcase .file(let name, let size): // immutable value 'name' was never used; consider replacing with '_' or removing itcase .file(let name, let size): // immutable value 'size' was never used; consider replacing with '_' or removing itcase .directory(let name, let contents): // immutable value 'name' was never used; consider replacing with '_' or removing itfunc getInfo() -> FileSystemInfo { // 'FileSystemInfo' is ambiguous for type lookup in this contextclass FileSystemInfo { // invalid redeclaration of 'FileSystemInfo'func getInfo() -> FileSystemInfo { // 'FileSystemInfo' is ambiguous for type lookup in this contextindirect enum FileSystemNode {
case file(name: String, size: Int)
case directory(name: String, contents: [FileSystemNode])
}
protocol FileSystemInfo {
var totalSize: Int { get }
var filesCount: Int { get }
var treeDepth: Int { get }
}
extension FileSystemNode: FileSystemInfo {
var totalSize: Int {
switch self {
case let .file(_, size):
return size
case let .directory(_, contents):
return contents.reduce(0) { $0 + $1.totalSize }
}
}
var filesCount: Int {
switch self {
case let .file(_):
return 1
case let .directory(_, contents):
return contents.reduce(0) { $0 + $1.filesCount }
}
}
var treeDepth: Int {
switch self {
case let .file(_):
return 1
case let .directory(_, contents):
return contents.reduce(0) { $0 > $1.treeDepth ? $0 : $1.treeDepth } + 1
}
}
}
extension FileSystemNode {
static func build(from root: String) -> FileSystemNode {
let rootNode = FileSystemNode.directory(name: root, contents: [])
let queue = [rootNode]
while !queue.isEmpty {
let node = queue.removeFirst()
let path = node.name
let size = Int(path.bridge(to: NSString.self).fileSystemRepresentation(as: Int.self))
if size == nil {
let contents = try! FileManager.default.contentsOfDirectory(atPath: path,
includingPropertiesForHiddenFiles: false,
options: .skipHiddenFiles)
let children = contents.map { FileSystemNode.directory(name: $0, contents: []) }
node = .directory(name: path, contents: children)
}
let file = .file(name: path, size: size!)
node.contents.append(file)
queue.append(contents)
}
return rootNode
}
}
extension FileSystemNode {
func calculateMetadata() -> FileSystemInfo {
return FileSystemNode.build(from: name)
}
}
class Solution {
func totalSize(_ root: String) -> Int {
let rootNode = FileSystemNode.directory(name: root, contents: [])
let queue = [rootNode]
while !queue.isEmpty {
let node = queue.removeFirst()
let path = node.name
let size = Int(path.bridge(to: NSString.self).fileSystemRepresentation(as: Int.self))
if size == nil {
let contents = try! FileManager.default.contentsOfDirectory(atPath: path,
includingPropertiesForHiddenFiles: false,
options: .skipHiddenFiles)
let children = contents.map { FileSystemNode.directory(name: $0, contents: []) }
node = .directory(name: path, contents: children)
}
let file = .file(name: path, size: size!)
node.contents.append(file)
queue.append(contents)
}
return rootNode.calculateMetadata().totalSize
}
}```swift
indirect enum FileSystemNode {
case file(name: String, size: Int)
case directory(name: String, contents: [FileSystemNode])
}
protocol FileSystemInfo {
var totalSize: Int { get }
var filesCount: Int { get }
var treeDepth: Int { get }
}
// Abstract file system manager and metadata calculation.
// Used to calculate total size of all files in file system, files count and file system tree depth.
extension FileSystemNode: FileSystemInfo {
var totalSize: Int {
switch self {
case let .file(_, size):
return size
case let .directory(_, contents):
return contents.reduce(0) { $0 + $1.totalSize }
}
}
var filesCount: Int {
switch self {
case let .file(_):
return 1
case let .directory(_, contents):
return contents.reduce(0) { $0 + $1.filesCount }
}
}
var treeDepth: Int {
switch self {
case let .file(_):
return 1
case let .directory(_, contents):
return contents.reduce(0) { $0 > $1.treeDepth ? $0 : $1.treeDepth } + 1
}
}
}
// Concrete file system manager and metadata calculation.
// Used to calculate total size of all files in file system, files count and file system tree depth.
extension FileSystemNode {
static func build(from root: String) -> FileSystemNode {
let rootNode = FileSystemNode.directory(name: root, contents: [])
let queue = [rootNode]
while !queue.isEmpty {
let node = queue.removeFirst()
let path = node.name
let size = Int(path.bridge(to: NSString.self).fileSystemRepresentation(as: Int.self))
if size == nil {
let contents = try! FileManager.default.contentsOfDirectory(atPath: path,
includingPropertiesForHiddenFiles: false,
options: .skipHiddenFiles)
let children = contents.map { FileSystemNode.directory(name: $0, contents: []) }
node = .directory(name: path, contents: children)
}
let file = .file(name: path, size: size!)
node.contents.append(file)
queue.append(contents)
}
return rootNode
}
}
// File system metadata calculation.
// Used to calculate total size of all files in file system, files count and file system tree depth.
extension FileSystemNode {
func calculateMetadata() -> FileSystemInfo {
return FileSystemNode.build(from: name)
}
}
```
### 解法二：递归
```swift
class Solution {
func totalSize(_ root: String) -> Int {
let rootNode = FileSystemNode.directory(name: root, contents: [])
let queue = [rootNode]
while !queue.isEmpty {
let node = queue.removeFirst()
let path = node.name
let size = Int(path.bridge(to: NSString.self).fileSystemRepresentation(as: Int.self))
if size == nil {
let contents = try! FileManager.default.contentsOfDirectory(atPath: path,
includingPropertiesForHiddenFiles: false,
options: .skipHiddenFiles)
let children = contents.map { FileSystemNode.directory(name: $0, contents: []) }
node = .directory(name: path, contents: children)
}
let file = .file(name: path, size: size!)
node.contents.append(file)
queue.append(contents)
}
return rootNode.calculateMetadata().totalSize
}
}
extension FileSystemNode {
var totalSize: Int {
switch self {
case let .file(_, size):
return size
case let .directory(_, contents):
return contents.reduce(0) { $0 + $1.totalSize }
}
}
var filesCount: Int {
switch self {
case let .file(_):
return 1
case let .directory(_, contents):
return contents.reduce(0) { $0 + $1.filesCount }
}
}
var treeDepth: Int {
switch self {
case let .file(_):
return 1
case let .directory(_, contents):
returncase let .file(_): // 'let' pattern has no effect; sub-pattern didn't bind any variablescase let .file(_): // enum case 'file' has 2 associated values; matching them as a tuple is deprecatedcase let .file(_): // enum case 'file' has 2 associated values; matching them as a tuple is deprecatedcase let .file(_): // 'let' pattern has no effect; sub-pattern didn't bind any variableslet node = queue.removeFirst() // cannot use mutating member on immutable value: 'queue' is a 'let' constantlet contents = try! FileManager.default.contentsOfDirectory(atPath: path, // extra arguments at positions #2, #3 in calloptions: .skipHiddenFiles) // cannot infer contextual base in reference to member 'skipHiddenFiles'let file = .file(name: path, size: size!) // reference to member 'file' cannot be resolved without a contextual typequeue.append(contents) // cannot find 'contents' in scopequeue.append(contents) // cannot use mutating member on immutable value: 'queue' is a 'let' constantreturn FileSystemNode.build(from: name) // cannot find 'name' in scopelet node = queue.removeFirst() // cannot use mutating member on immutable value: 'queue' is a 'let' constantlet contents = try! FileManager.default.contentsOfDirectory(atPath: path, // extra arguments at positions #2, #3 in calloptions: .skipHiddenFiles) // cannot infer contextual base in reference to member 'skipHiddenFiles'let file = .file(name: path, size: size!) // reference to member 'file' cannot be resolved without a contextual typequeue.append(contents) // cannot find 'contents' in scopequeue.append(contents) // cannot use mutating member on immutable value: 'queue' is a 'let' constantindirect enum FileSystemNode {
case file(name: String, size: Int)
case directory(name: String, contents: [FileSystemNode])
}
protocol FileSystemInfo {
var totalSize: Int { get }
var filesCount: Int { get }
var treeDepth: Int { get }
}
extension FileSystemNode: FileSystemInfo {
var totalSize: Int {
switch self {
case .file(let name, let size):
return size
case .directory(let name, let contents):
return contents.reduce(0) { $0 + $1.totalSize }
}
}
var filesCount: Int {
switch self {
case .file(let name, _):
return 1
case .directory(let name, let contents):
return contents.count
}
}
var treeDepth: Int {
switch self {
case .file(_, _):
return 1
case .directory(_, let contents):
return contents.reduce(0) { $0 > 1 ? $0 : 1 + $1.treeDepth }
}
}
}
extension FileSystemNode {
static func fromPath(_ path: String) -> FileSystemNode {
let filePaths = FileManager.default.contentsOfDirectory(at: URL(fileURLWithPath: path),
includingHiddenFiles: true,
options: .skipsHiddenFiles)
let directoryContents = filePaths.map { FileSystemNode.file(name: $0, size: 0) }
return FileSystemNode.directory(name: path, contents: directoryContents)
}
}
extension FileSystemNode {
func getFileSystemInfo() -> FileSystemInfo {
return FileSystemNode.fromPath(self.name)
}
}```swift
indirect enum FileSystemNode {
case file(name: String, size: Int)
case directory(name: String, contents: [FileSystemNode])
}
protocol FileSystemInfo {
var totalSize: Int { get }
var filesCount: Int { get }
var treeDepth: Int { get }
}
// Abstract file system manager and metadata calculation.
// Used to calculate total size of all files in file system, files count and file system tree depth.
extension FileSystemNode: FileSystemInfo {
var totalSize: Int {
switch self {
case .file(let name, let size):
return size
case .directory(let name, let contents):
return contents.reduce(0) { $0 + $1.totalSize }
}
}
var filesCount: Int {
switch self {
case .file(let name, _):
return 1
case .directory(let name, let contents):
return contents.count
}
}
var treeDepth: Int {
switch self {
case .file(_, _):
return 1
case .directory(_, let contents):
return contents.reduce(0) { $0 > 1 ? $0 : 1 + $1.treeDepth }
}
}
}
// Concrete file system manager and metadata calculation.
// Used to calculate total size of all files in file system, files count and file system tree depth.
extension FileSystemNode {
static func fromPath(_ path: String) -> FileSystemNode {
let filePaths = FileManager.default.contentsOfDirectory(at: URL(fileURLWithPath: path),
includingHiddenFiles: true,
options: .skipsHiddenFiles)
let directoryContents = filePaths.map { FileSystemNode.file(name: $0, size: 0) }
return FileSystemNode.directory(name: path, contents: directoryContents)
}
}
// Concrete file system manager and metadata calculation.
// Used to calculate total size of all files in file system, files count and file system tree depth.
extension FileSystemNode {
func getFileSystemInfo() -> FileSystemInfo {
return FileSystemNode.fromPath(self.name)
}
}
// Concrete file system manager and metadata calculation.
// Used to calculate total size of all files in file system, files count and file system tree depth.
extension FileSystemNode {
func getFileSystemInfo() -> FileSystemInfo {
return FileSystemNode.fromPath(self.name)
}
}
// Concrete file system manager and metadata calculation.
// Used to calculate total size of all files in file system, files count and file system tree depth.
extension FileSystemNode {
func getFileSystemInfo() -> FileSystemInfo {
return FileSystemNode.fromPath(self.name)
}
}
// Concrete file system manager and metadata calculation.
// Used to calculate total size of all files in file system, files count and file system tree depth.
extension FileSystemNode {
func getFileSystemInfo() -> FileSystemInfo {
return FileSystemNode.fromPath(self.name)
}
}
// Concrete file system manager and metadata calculation.
// Used to calculate total size of all files in file system, files count and file system tree depth.
extension FileSystemNode {
func getFileSystemInfo() -> FileSystemInfo {
return FileSystemNode.fromPath(self.name)
}
}
// Concrete file system manager and metadata calculation.
// Used to calculate total size of all files in file system, files count and file system tree depth.
extension FileSystemNode {
func getFileSystemInfo() -> FileSystemInfo {
return FileSystemNode.fromPath(self.name)
}
}
// Concrete file system manager and metadata calculation.
// Used to calculate total size of all files in file system, files count and file system tree depth.
extension FileSystemNode {
func getFileSystemInfo() -> FileSystemInfo {
return FileSystemNode.fromPath(self.name)
}
}
// Concrete file system manager and metadata calculation.
// Used to calculate total size of all files in file system, files count and file system tree depth.
extension FileSystemNode {
func getFileSystemInfo() -> FileSystemInfo {
return FileSystemNode.fromPath(self.name)
}
}
// Concrete file system manager and metadata calculation.
// Used to calculate total size of all files in file system, files count and file system tree depth.
extension FileSystemNode {
func getFileSystemInfo() -> FileSystemInfo {
return FileSystemNode.fromPath(self.name)
}
}
case .file(let name, let size): // immutable value 'name' was never used; consider replacing with '_' or removing itcase .directory(let name, let contents): // immutable value 'name' was never used; consider replacing with '_' or removing itcase .file(let name, _): // immutable value 'name' was never used; consider replacing with '_' or removing itcase .directory(let name, let contents): // immutable value 'name' was never used; consider replacing with '_' or removing itlet filePaths = FileManager.default.contentsOfDirectory(at: URL(fileURLWithPath: path), // incorrect argument label in call (have 'at:includingHiddenFiles:options:', expected 'at:includingPropertiesForKeys:options:')includingHiddenFiles: true, // cannot convert value of type 'Bool' to expected argument type '[URLResourceKey]?'return FileSystemNode.fromPath(self.name) // value of type 'FileSystemNode' has no member 'name'indirect enum FileSystemNode {
case file(name: String, size: Int)
case directory(name: String, contents: [FileSystemNode])
}
protocol FileSystemInfo {
var totalSize: Int { get }
var filesCount: Int { get }
var treeDepth: Int { get }
}
extension FileSystemNode: FileSystemInfo {
var totalSize: Int {
switch self {
case let .file(_, size):
return size
case let .directory(_, contents):
return contents.reduce(0) { $0 + $1.totalSize }
}
}
var filesCount: Int {
switch self {
case let .file(_):
return 1
case let .directory(_, contents):
return contents.reduce(0) { $0 + $1.filesCount }
}
}
var treeDepth: Int {
switch self {
case let .file(_):
return 1
case let .directory(_, contents):
return contents.reduce(0) { $0 > $1.treeDepth ? $0 : $1.treeDepth } + 1
}
}
}
class FileSystemManager {
// Calculates total size of all files in file system.
func getTotalSize() -> Int {
return root.totalSize
}
// Calculates files count in file system.
func getFilesCount() -> Int {
return root.filesCount
}
// Calculates file system tree depth.
func getTreeDepth() -> Int {
return root.treeDepth
}
// Initializes file system manager.
init(_ root: FileSystemNode) {
self.root = root
}
// File system root node.
private var root: FileSystemNode
}
func totalSize(_ fileSystem: [String]) -> Int {
let fileSystemManager = FileSystemManager(FileSystemNode.directory(name: "", contents: fileSystem.map { FileSystemNode.file(name: $0, size: 1) }))
return fileSystemManager.getTotalSize()
}
func filesCount(_ fileSystem: [String]) -> Int {
let fileSystemManager = FileSystemManager(FileSystemNode.directory(name: "", contents: fileSystem.map { FileSystemNode.file(name: $0, size: 1) }))
return fileSystemManager.getFilesCount()
}
func treeDepth(_ fileSystem: [String]) -> Int {
let fileSystemManager = FileSystemManager(FileSystemNode.directory(name: "", contents: fileSystem.map { FileSystemNode.file(name: $0, size: 1) }))
return fileSystemManager.getTreeDepth()
}```swift
indirect enum FileSystemNode {
case file(name: String, size: Int)
case directory(name: String, contents: [FileSystemNode])
}
protocol FileSystemInfo {
var totalSize: Int { get }
var filesCount: Int { get }
var treeDepth: Int { get }
}
// Abstract file system manager and metadata calculation.
// Used to calculate total size of all files in file system, files count and file system tree depth.
extension FileSystemNode: FileSystemInfo {
var totalSize: Int {
switch self {
case let .file(_, size):
return size
case let .directory(_, contents):
return contents.reduce(0) { $0 + $1.totalSize }
}
}
var filesCount: Int {
switch self {
case let .file(_):
return 1
case let .directory(_, contents):
return contents.reduce(0) { $0 + $1.filesCount }
}
}
var treeDepth: Int {
switch self {
case let .file(_):
return 1
case let .directory(_, contents):
return contents.reduce(0) { $0 > $1.treeDepth ? $0 : $1.treeDepth } + 1
}
}
}
// File system manager implementation.
class FileSystemManager {
// Calculates total size of all files in file system.
func getTotalSize() -> Int {
return root.totalSize
}
// Calculates files count in file system.
func getFilesCount() -> Int {
return root.filesCount
}
// Calculates file system tree depth.
func getTreeDepth() -> Int {
return root.treeDepth
}
// Initializes file system manager.
init(_ root: FileSystemNode) {
self.root = root
}
// File system root node.
private var root: FileSystemNode
}
// MARK: - Solution
// Calculates total size of all files in file system.
func totalSize(_ fileSystem: [String]) -> Int {
let fileSystemManager = FileSystemManager(FileSystemNode.directory(name: "", contents: fileSystem.map { FileSystemNode.file(name: $0, size: 1) }))
return fileSystemManager.getTotalSize()
}
// Calculates files count in file system.
func filesCount(_ fileSystem: [String]) -> Int {
let fileSystemManager = FileSystemManager(FileSystemNode.directory(name: "", contents: fileSystem.map { FileSystemNode.file(name: $0, size: 1) }))
return fileSystemManager.getFilesCount()
}
// Calculates file system tree depth.
func treeDepth(_ fileSystem: [String]) -> Int {
let fileSystemManager = FileSystemManager(FileSystemNode.directory(name: "", contents: fileSystem.map { FileSystemNode.file(name: $0, size: 1) }))
return fileSystemManager.getTreeDepth()
}
```case let .file(_): // 'let' pattern has no effect; sub-pattern didn't bind any variablescase let .file(_): // enum case 'file' has 2 associated values; matching them as a tuple is deprecatedcase let .file(_): // 'let' pattern has no effect; sub-pattern didn't bind any variablescase let .file(_): // enum case 'file' has 2 associated values; matching them as a tuple is deprecatedindirect enum FileSystemNode {
case file(name: String, size: Int)
case directory(name: String, contents: [FileSystemNode])
}
protocol FileSystemInfo {
var totalSize: Int { get }
var filesCount: Int { get }
var treeDepth: Int { get }
}
extension FileSystemNode: FileSystemInfo {
var totalSize: Int {
switch self {
case .file(let name, let size):
return size
case .directory(let name, let contents):
return contents.reduce(0) { $0 + $1.totalSize }
}
}
var filesCount: Int {
switch self {
case .file(let name, let size):
return 1
case .directory(let name, let contents):
return contents.reduce(0) { $0 + $1.filesCount }
}
}
var treeDepth: Int {
switch self {
case .file(let name, let size):
return 1
case .directory(let name, let contents):
return contents.reduce(0) { $0 > $1.treeDepth ? $0 : $1.treeDepth } + 1
}
}
}
class FileSystemManager {
func getFileSystemInfo(_ root: FileSystemNode) -> FileSystemInfo {
return root
}
}```swift
indirect enum FileSystemNode {
case file(name: String, size: Int)
case directory(name: String, contents: [FileSystemNode])
}
protocol FileSystemInfo {
var totalSize: Int { get }
var filesCount: Int { get }
var treeDepth: Int { get }
}
// Abstract file system manager and metadata calculation.
// Used to calculate total size of all files in file system, files count and file system tree depth.
extension FileSystemNode: FileSystemInfo {
var totalSize: Int {
switch self {
case .file(let name, let size):
return size
case .directory(let name, let contents):
return contents.reduce(0) { $0 + $1.totalSize }
}
}
var filesCount: Int {
switch self {
case .file(let name, let size):
return 1
case .directory(let name, let contents):
return contents.reduce(0) { $0 + $1.filesCount }
}
}
var treeDepth: Int {
switch self {
case .file(let name, let size):
return 1
case .directory(let name, let contents):
return contents.reduce(0) { $0 > $1.treeDepth ? $0 : $1.treeDepth } + 1
}
}
}
// Concrete file system manager.
// Used to calculate file system tree depth.
class FileSystemManager {
func getFileSystemInfo(_ root: FileSystemNode) -> FileSystemInfo {
return root
}
}
// Concrete file system manager.
// Used to calculate file system tree depth.
class FileSystemManager {
func getFileSystemInfo(_ root: FileSystemNode) -> FileSystemInfo {
return root
}
}
// Concrete file system manager.
// Used to calculate file system tree depth.
class FileSystemManager {
func getFileSystemInfo(_ root: FileSystemNode) -> FileSystemInfo {
return root
}
}
// Concrete file system manager.
// Used to calculate file system tree depth.
class FileSystemManager {
func getFileSystemInfo(_ root: FileSystemNode) -> FileSystemInfo {
return root
}
}
// Concrete file system manager.
// Used to calculate file system tree depth.
class FileSystemManager {
func getFileSystemInfo(_ root: FileSystemNode) -> FileSystemInfo {
return root
}
}
// Concrete file system manager.
// Used to calculate file system tree depth.
class FileSystemManager {
func getFileSystemInfo(_ root: FileSystemNode) -> FileSystemInfo {
return root
}
}
// Concrete file system manager.
// Used to calculate file system tree depth.
class FileSystemManager {
func getFileSystemInfo(_ root: FileSystemNode) -> FileSystemInfo {
return root
}
}
// Concrete file system manager.
// Used to calculate file system tree depth.
class FileSystemManager {
func getFileSystemInfo(_ root: FileSystemNode) -> FileSystemInfo {
return root
}
}
// Concrete file system manager.
// Used to calculate file system tree depth.
class FileSystemManager {
func getFileSystemInfo(_ root: FileSystemNode) -> FileSystemInfo {
return root
}
}
// Concrete file system manager.
// Used to calculate file system tree depth.
class FileSystemManager {
func getFileSystemInfo(_ root: FileSystemNode) -> FileSystemInfo {
return root
}
}
// Concrete file system manager.
// Used to calculate file system tree depth.
class FileSystemManager {
func getFileSystemInfo(_ root: FileSystemNode) -> FileSystemInfo {
return root
}
}
// Concrete file system manager.
// Used to calculate file system tree depth.
class FileSystemManager {
func getFileSystemInfo(_ root: FileSystemNode) -> FileSystemInfo {
return root
}
}
// Concrete file system manager.
// Used to calculate file system tree depth.
class FileSystemManager {
func getFileSystemInfo(_ root: FileSystemNode) -> FileSystemInfo {
return root
}
}
// Concrete file system manager.
// Used to calculate file system tree depth.
class FileSystemManager {
func getFileSystemInfo(_ root: FileSystemNode) -> FileSystemInfo {
return root
}
}
// Concrete file system manager.
// Used to calculate file system tree depth.
class FileSystemManager {
func getFileSystemInfo(_ root: FileSystemNode) -> FileSystemInfo {
return root
}
}
// Concretecase .file(let name, let size): // immutable value 'name' was never used; consider replacing with '_' or removing itcase .directory(let name, let contents): // immutable value 'name' was never used; consider replacing with '_' or removing itcase .file(let name, let size): // immutable value 'size' was never used; consider replacing with '_' or removing itcase .file(let name, let size): // immutable value 'name' was never used; consider replacing with '_' or removing itcase .directory(let name, let contents): // immutable value 'name' was never used; consider replacing with '_' or removing itcase .file(let name, let size): // immutable value 'name' was never used; consider replacing with '_' or removing itcase .file(let name, let size): // immutable value 'size' was never used; consider replacing with '_' or removing itcase .directory(let name, let contents): // immutable value 'name' was never used; consider replacing with '_' or removing itindirect enum FileSystemNode {
case file(name: String, size: Int)
case directory(name: String, contents: [FileSystemNode])
}
protocol FileSystemInfo {
var totalSize: Int { get }
var filesCount: Int { get }
var treeDepth: Int { get }
}
extension FileSystemNode: FileSystemInfo {
var totalSize: Int {
switch self {
case let .file(_, size): return size
case let .directory(_, contents): return contents.reduce(0) { $0 + $1.totalSize }
}
}
var filesCount: Int {
switch self {
case let .file(_): return 1
case let .directory(_, contents): return contents.reduce(0) { $0 + $1.filesCount }
}
}
var treeDepth: Int {
switch self {
case let .file(_): return 1
case let .directory(_, contents): return contents.reduce(0) { $0 > $1.treeDepth ? $0 : $1.treeDepth } + 1
}
}
}
class FileSystemManager {
private let root: FileSystemNode
init(_ root: FileSystemNode) {
self.root = root
}
func getTotalSize() -> Int {
return root.totalSize
}
func getFilesCount() -> Int {
return root.filesCount
}
func getTreeDepth() -> Int {
return root.treeDepth
}
}
class FileSystemMetadataCalculator {
private let fileSystemManager: FileSystemManager
init(_ fileSystemManager: FileSystemManager) {
self.fileSystemManager = fileSystemManager
}
func getTotalSize() -> Int {
return fileSystemManager.getTotalSize()
}
func getFilesCount() -> Int {
return fileSystemManager.getFilesCount()
}
func getTreeDepth() -> Int {
return fileSystemManager.getTreeDepth()
}
}```swift
indirect enum FileSystemNode {
case file(name: String, size: Int)
case directory(name: String, contents: [FileSystemNode])
}
protocol FileSystemInfo {
var totalSize: Int { get }
var filesCount: Int { get }
var treeDepth: Int { get }
}
// Abstract file system manager and metadata calculation.
// Used to calculate total size of all files in file system, files count and file system tree depth.
extension FileSystemNode: FileSystemInfo {
var totalSize: Int {
switch self {
case let .file(_, size): return size
case let .directory(_, contents): return contents.reduce(0) { $0 + $1.totalSize }
}
}
var filesCount: Int {
switch self {
case let .file(_): return 1
case let .directory(_, contents): return contents.reduce(0) { $0 + $1.filesCount }
}
}
var treeDepth: Int {
switch self {
case let .file(_): return 1
case let .directory(_, contents): return contents.reduce(0) { $0 > $1.treeDepth ? $0 : $1.treeDepth } + 1
}
}
}
// File system manager implementation.
// Used to calculate file system tree depth and file system tree size.
class FileSystemManager {
private let root: FileSystemNode
init(_ root: FileSystemNode) {
self.root = root
}
func getTotalSize() -> Int {
return root.totalSize
}
func getFilesCount() -> Int {
return root.filesCount
}
func getTreeDepth() -> Int {
return root.treeDepth
}
}
// File system metadata calculation.
// Used to calculate file system tree depth and file system tree size.
class FileSystemMetadataCalculator {
private let fileSystemManager: FileSystemManager
init(_ fileSystemManager: FileSystemManager) {
self.fileSystemManager = fileSystemManager
}
func getTotalSize() -> Int {
return fileSystemManager.getTotalSize()
}
func getFilesCount() -> Int {
return fileSystemManager.getFilesCount()
}
func getTreeDepth() -> Int {
return fileSystemManager.getTreeDepth()
}
}
// File system metadata calculation.
// Used to calculate file system tree depth and file system tree size.
class FileSystemMetadataCalculator {
private let fileSystemManager: FileSystemManager
init(_ fileSystemManager: FileSystemManager) {
self.fileSystemManager = fileSystemManager
}
func getTotalSize() -> Int {
return fileSystemManager.getTotalSize()
}
func getFilesCount() -> Int {
return fileSystemManager.getFilesCount()
}
func getTreeDepth() -> Int {
return fileSystemManager.getTreeDepth()
}
}
// File system metadata calculation.
// Used to calculate file system tree depth and file system tree size.
class FileSystemMetadataCalculator {
private let fileSystemManager: FileSystemManager
init(_ fileSystemManager: FileSystemManager) {
self.fileSystemManager = fileSystemManager
}
func getTotalSize() -> Int {
return fileSystemManager.getTotalSize()
}
func getFilesCount() -> Int {
return fileSystemManager.getFilesCount()
}
func getTreeDepth() -> Int {
return fileSystemManager.getTreeDepth()
}
}
// File system metadata calculation.
// Used to calculate file system tree depth and file system tree size.
class FileSystemMetadataCalculator {
private let fileSystemManager: FileSystemManager
init(_ fileSystemManager: FileSystemManager) {
self.fileSystemManager = fileSystemManager
}
func getTotalSize() -> Int {
return fileSystemManager.getTotalSize()
}
func getFilesCount() -> Int {
return fileSystemManager.getFilesCount()
}
func getTreeDepth() -> Int {
return fileSystemManager.getTreeDepth()
}
}
// File system metadata calculation.
// Used to calculate file system tree depth and file system tree size.
class FileSystemMetadataCalculator {
private let fileSystemManager: FileSystemManager
init(_ fileSystemManager: FileSystemManager) {
self.fileSystemManager = fileSystemManager
}
func getTotalSize() -> Int {
case let .file(_): return 1 // enum case 'file' has 2 associated values; matching them as a tuple is deprecatedcase let .file(_): return 1 // 'let' pattern has no effect; sub-pattern didn't bind any variablescase let .file(_): return 1 // 'let' pattern has no effect; sub-pattern didn't bind any variablescase let .file(_): return 1 // enum case 'file' has 2 associated values; matching them as a tuple is deprecatedprotocol StackProtocol {
associatedtype Element
init()
func push(_ element: Element)
func pop() -> Element?
}
class Stack<Element> {
private var elements: [Element] = []
// MARK: - Lifecycle
init() {}
// MARK: - Public
func push(_ element: Element) {
elements.append(element)
}
func pop() -> Element? {
return elements.popLast()
}
}
extension StackProtocol {
// MARK: - Lifecycle
init() {
self.init()
}
// MARK: - Public
func push(_ element: Element) {
self.push(element)
}
func pop() -> Element? {
return self.pop()
}
}
class Stack<Element: Equatable> {
private var elements: [Element] = []
// MARK: - Lifecycle
init() {}
// MARK: - Public
func push(_ element: Element) {
elements.append(element)
}
func pop() -> Element? {
return elements.popLast()
}
}```swift
protocol StackProtocol {
associatedtype Element
init()
func push(_ element: Element)
func pop() -> Element?
}
// Generic stack with push and pop functions.
class Stack<Element> {
private var elements: [Element] = []
// MARK: - Lifecycle
init() {}
// MARK: - Public
func push(_ element: Element) {
elements.append(element)
}
func pop() -> Element? {
return elements.popLast()
}
}
// MARK: - Protocol extensions
extension StackProtocol {
// MARK: - Lifecycle
init() {
self.init()
}
// MARK: - Public
func push(_ element: Element) {
self.push(element)
}
func pop() -> Element? {
return self.pop()
}
}
```
### 2. 泛型扩展
```swift
protocol StackProtocol {
associatedtype Element
init()
func push(_ element: Element)
func pop() -> Element?
}
// Generic stack with push and pop functions.
class Stack<Element> {
private var elements: [Element] = []
// MARK: - Lifecycle
init() {}
// MARK: - Public
func push(_ element: Element) {
elements.append(element)
}
func pop() -> Element? {
return elements.popLast()
}
}
// MARK: - Protocol extensions
extension StackProtocol {
// MARK: - Lifecycle
init() {
self.init()
}
// MARK: - Public
func push(_ element: Element) {
self.push(element)
}
func pop() -> Element? {
return self.pop()
}
}
```
### 3. 泛型扩展 + 泛型参数
```swift
protocol StackProtocol {
associatedtype Element
init()
func push(_ element: Element)
func pop() -> Element?
}
// Generic stack with push and pop functions.
class Stack<Element> {
private var elements: [Element] = []
// MARK: - Lifecycle
init() {}
// MARK: - Public
func push(_ element: Element) {
elements.append(element)
}
func pop() -> Element? {
return elements.popLast()
}
}
// MARK: - Protocol extensions
extension StackProtocol {
// MARK: - Lifecycle
init() {
self.init()
}
// MARK: - Public
func push(_ element: Element) {
self.push(element)
}
func pop() -> Element? {
return self.pop()
}
}
```
### 4. 泛型扩展 + 泛型参数 + 泛型约束
```swift
protocol StackProtocol {
associatedtype Element
init()
func push(_ element: Element)
func pop() -> Element?
}
// Generic stack with push and pop functions.
class Stack<Element: Equatable> {
private var elements: [Element] = []
// MARK: - Lifecycle
init() {}
// MARK: - Public
func push(_ element: Element) {
elements.append(element)
}
func pop() -> Element? {
return elements.popLast()
}
}
// MARK: - Protocol extensions
extension StackProtocol {
// MARK: - Lifecycle
init() {
self.init()
}
// MARK: - Public
func push(_ element: Element) {
self.push(element)
}
func pop() -> Element? {
return self.pop()
}
}
```
### 5. 泛型扩展 + 泛型参数 + 泛型约束 +class Stack<Element: Equatable> { // invalid redeclaration of 'Stack'var stack = Stack<Int>() // variable 'stack' was never mutated; consider changing to 'let' constantprotocol StackProtocol {
associatedtype Element
init()
func push(_ element: Element)
func pop() -> Element?
}
class Stack<Element>: StackProtocol {
private var elements: [Element] = []
// MARK: - Lifecycle
init() {}
// MARK: - Public
func push(_ element: Element) {
elements.append(element)
}
func pop() -> Element? {
return elements.popLast()
}
}
extension StackProtocol {
// MARK: - Lifecycle
init() {
self.init()
}
// MARK: - Public
func push(_ element: Element) {
self.push(element)
}
func pop() -> Element? {
return self.pop()
}
}
extension StackProtocol {
// MARK: - Lifecycle
func push(_ element: Element) {
self.push(element)
}
func pop() -> Element? {
return self.pop()
}
}```swift
protocol StackProtocol {
associatedtype Element
init()
func push(_ element: Element)
func pop() -> Element?
}
// Generic stack with push and pop functions.
class Stack<Element>: StackProtocol {
private var elements: [Element] = []
// MARK: - Lifecycle
init() {}
// MARK: - Public
func push(_ element: Element) {
elements.append(element)
}
func pop() -> Element? {
return elements.popLast()
}
}
// MARK: - Lifecycle
extension StackProtocol {
// MARK: - Lifecycle
init() {
self.init()
}
// MARK: - Public
func push(_ element: Element) {
self.push(element)
}
func pop() -> Element? {
return self.pop()
}
}
// MARK: - Lifecycle
extension StackProtocol {
// MARK: - Lifecycle
func push(_ element: Element) {
self.push(element)
}
func pop() -> Element? {
return self.pop()
}
}
// MARK: - Lifecycle
extension StackProtocol {
// MARK: - Lifecycle
func push(_ element: Element) {
self.push(element)
}
func pop() -> Element? {
return self.pop()
}
}
// MARK: - Lifecycle
extension StackProtocol {
// MARK: - Lifecycle
func push(_ element: Element) {
self.push(element)
}
func pop() -> Element? {
return self.pop()
}
}
// MARK: - Lifecycle
extension StackProtocol {
// MARK: - Lifecycle
func push(_ element: Element) {
self.push(element)
}
func pop() -> Element? {
return self.pop()
}
}
// MARK: - Lifecycle
extension StackProtocol {
// MARK: - Lifecycle
func push(_ element: Element) {
self.push(element)
}
func pop() -> Element? {
return self.pop()
}
}
// MARK: - Lifecycle
extension StackProtocol {
// MARK: - Lifecycle
func push(_ element: Element) {
self.push(element)
}
func pop() -> Element? {
return self.pop()
}
}
// MARK: - Lifecycle
extension StackProtocol {
// MARK: - Lifecycle
func push(_ element: Element) {
self.push(element)
}
func pop() -> Element? {
return self.pop()
}
}
// MARK: - Lifecycle
extension StackProtocol {
// MARK: - Lifecycle
func push(_ element: Element) {
self.push(element)
}
func pop() -> Element? {
return self.pop()
}
}
// MARK: - Lifecycle
extension StackProtocol {
// MARK: - Lifecycle
func push(_ element: Element) {
self.push(element)
}
func pop() -> Element? {
return self.pop()
}
}
// MARK: - Lifecycle
extension StackProtocol {
// MARK: - Lifecycle
func push(_ element: Element) {
self.push(element)
}
func pop() -> Element? {
return self.pop()
}
}
// MARK: - Lifecycle
extension StackProtocol {
// MARK: - Lifecycle
func push(_ element: Element) {
self.push(element)
}
func pop() -> Element? {
returninit() {} // initializer requirement 'init()' can only be satisfied by a 'required' initializer in non-final class 'Stack<Element>'func push(_ element: Element) { // invalid redeclaration of 'push'func pop() -> Element? { // invalid redeclaration of 'pop()'var stack = Stack<Int>() // variable 'stack' was never mutated; consider changing to 'let' constantprotocol StackProtocol {
associatedtype Element
init()
func push(_ element: Element)
func pop() -> Element?
}
class Stack<Element> {
private var elements: [Element] = []
// MARK: - StackProtocol
// MARK: - Init
init() {}
// MARK: - Push
func push(_ element: Element) {
elements.append(element)
}
// MARK: - Pop
func pop() -> Element? {
return elements.popLast()
}
}
extension StackProtocol {
// MARK: - Push
@discardableResult
mutating func push(_ element: Element) -> Self {
self.push(element)
return self
}
// MARK: - Pop
@discardableResult
mutating func pop() -> Element? {
return self.pop()
}
}
protocol StackProtocol: GenericStackProtocol {
associatedtype Element
init()
func push(_ element: Element)
func pop() -> Element?
}
class Stack<Element>: StackProtocol {
private var elements: [Element] = []
// MARK: - StackProtocol
// MARK: - Init
init() {}
// MARK: - Push
func push(_ element: Element) {
elements.append(element)
}
// MARK: - Pop
func pop() -> Element? {
return elements.popLast()
}
}```swift
protocol StackProtocol {
associatedtype Element
init()
func push(_ element: Element)
func pop() -> Element?
}
// Generic stack with push and pop functions.
class Stack<Element> {
private var elements: [Element] = []
// MARK: - StackProtocol
// MARK: - Init
init() {}
// MARK: - Push
func push(_ element: Element) {
elements.append(element)
}
// MARK: - Pop
func pop() -> Element? {
return elements.popLast()
}
}
// MARK: - Stack
extension StackProtocol {
// MARK: - Push
@discardableResult
mutating func push(_ element: Element) -> Self {
self.push(element)
return self
}
// MARK: - Pop
@discardableResult
mutating func pop() -> Element? {
return self.pop()
}
}
```
### 2. 泛型扩展
```swift
protocol StackProtocol {
associatedtype Element
init()
func push(_ element: Element)
func pop() -> Element?
}
// Generic stack with push and pop functions.
class Stack<Element> {
private var elements: [Element] = []
// MARK: - StackProtocol
// MARK: - Init
init() {}
// MARK: - Push
func push(_ element: Element) {
elements.append(element)
}
// MARK: - Pop
func pop() -> Element? {
return elements.popLast()
}
}
// MARK: - Stack
extension StackProtocol {
// MARK: - Push
@discardableResult
mutating func push(_ element: Element) -> Self {
self.push(element)
return self
}
// MARK: - Pop
@discardableResult
mutating func pop() -> Element? {
return self.pop()
}
}
```
### 3. 泛型扩展 + 泛型参数
```swift
protocol StackProtocol {
associatedtype Element
init()
func push(_ element: Element)
func pop() -> Element?
}
// Generic stack with push and pop functions.
class Stack<Element> {
private var elements: [Element] = []
// MARK: - StackProtocol
// MARK: - Init
init() {}
// MARK: - Push
func push(_ element: Element) {
elements.append(element)
}
// MARK: - Pop
func pop() -> Element? {
return elements.popLast()
}
}
// MARK: - Stack
extension StackProtocol {
// MARK: - Push
@discardableResult
mutating func push(_ element: Element) -> Self {
self.push(element)
return self
}
// MARK: - Pop
@discardableResult
mutating func pop() -> Element? {
return self.pop()
}
}
```
### 4. 泛型扩展 + 泛型参数 + 泛型约束
```swift
protocol StackProtocol: GenericStackProtocol {
associatedtype Element
init()
func push(_ element: Element)
func pop() -> Element?
}
// Generic stack with push and pop functions.
class Stack<Element>: StackProtocol {
private var elements: [Element] = []
// MARK: - StackProtocol
// MARK: - Init
init() {}
// MARK: - Push
func push(_ element: Element) {
elements.append(element)
}
// MARK: - Pop
func pop() -> Element? {
return elements.popLast()
}
}
// MARK: - Stack
extension StackProtocol {
// MARK:extension StackProtocol { // 'StackProtocol' is ambiguous for type lookup in this contextprotocol StackProtocol: GenericStackProtocol { // cannot find type 'GenericStackProtocol' in scopeprotocol StackProtocol: GenericStackProtocol { // invalid redeclaration of 'StackProtocol'class Stack<Element>: StackProtocol { // 'StackProtocol' is ambiguous for type lookup in this contextclass Stack<Element>: StackProtocol { // invalid redeclaration of 'Stack'var stack = Stack<Int>() // variable 'stack' was never mutated; consider changing to 'let' constantprotocol StackProtocol {
associatedtype Element
init()
func push(_ element: Element)
func pop() -> Element?
}
class Stack<Element> {
var elements: [Element] = []
// MARK: - push
func push(_ element: Element) {
elements.append(element)
}
// MARK: - pop
func pop() -> Element? {
return elements.popLast()
}
}
extension Stack: StackProtocol {}
// MARK: - StackProtocol
extension StackProtocol {
// MARK: - init
public init() {}
// MARK: - push
public func push(_ element: Element) {
self.push(element)
}
// MARK: - pop
public func pop() -> Element? {
return self.pop()
}
}
extension StackProtocol {
// MARK: - push
public func push(_ element: Element) {
self.push(element)
}
// MARK: - pop
public func pop() -> Element? {
return self.pop()
}
}```swift
protocol StackProtocol {
associatedtype Element
init()
func push(_ element: Element)
func pop() -> Element?
}
// Generic stack with push and pop functions.
class Stack<Element> {
var elements: [Element] = []
// MARK: - push
func push(_ element: Element) {
elements.append(element)
}
// MARK: - pop
func pop() -> Element? {
return elements.popLast()
}
}
// MARK: - StackProtocol
extension Stack: StackProtocol {}
// MARK: - StackProtocol
extension StackProtocol {
// MARK: - init
public init() {}
// MARK: - push
public func push(_ element: Element) {
self.push(element)
}
// MARK: - pop
public func pop() -> Element? {
return self.pop()
}
}
// MARK: - StackProtocol
extension StackProtocol {
// MARK: - push
public func push(_ element: Element) {
self.push(element)
}
// MARK: - pop
public func pop() -> Element? {
return self.pop()
}
}
// MARK: - StackProtocol
extension StackProtocol {
// MARK: - push
public func push(_ element: Element) {
self.push(element)
}
// MARK: - pop
public func pop() -> Element? {
return self.pop()
}
}
// MARK: - StackProtocol
extension StackProtocol {
// MARK: - push
public func push(_ element: Element) {
self.push(element)
}
// MARK: - pop
public func pop() -> Element? {
return self.pop()
}
}
// MARK: - StackProtocol
extension StackProtocol {
// MARK: - push
public func push(_ element: Element) {
self.push(element)
}
// MARK: - pop
public func pop() -> Element? {
return self.pop()
}
}
// MARK: - StackProtocol
extension StackProtocol {
// MARK: - push
public func push(_ element: Element) {
self.push(element)
}
// MARK: - pop
public func pop() -> Element? {
return self.pop()
}
}
// MARK: - StackProtocol
extension StackProtocol {
// MARK: - push
public func push(_ element: Element) {
self.push(element)
}
// MARK: - pop
public func pop() -> Element? {
return self.pop()
}
}
// MARK: - StackProtocol
extension StackProtocol {
// MARK: - push
public func push(_ element: Element) {
self.push(element)
}
// MARK: - pop
public func pop() -> Element? {
return self.pop()
}
}
// MARK: - StackProtocol
extension StackProtocol {
// MARK: - push
public func push(_ element: Element) {
self.push(element)
}
// MARK: - pop
public func pop() -> Element? {
return self.pop()
}
}
// MARK: - StackProtocol
extension StackProtocol {
// MARK: - push
public func push(_ element: Element) {
self.push(element)
}
// MARK: - pop
public func pop() -> Element? {
return self.pop()
}
}
// MARK: - StackProtocol
extension StackProtocol {
// MARK: - push
public func push(_ element: Element) {
self.push(element)
}
// MARK: - pop
public func pop() -> Element? {
return self.pop()
}
}
// MARK: - StackProtocol
extension StackProtocol {
// MARK: - push
public func push(_ element: Element) {
self.push(elementextension Stack: StackProtocol {} // initializer requirement 'init()' can only be satisfied by a 'required' initializer in non-final class 'Stack<Element>'public func push(_ element: Element) { // invalid redeclaration of 'push'public func pop() -> Element? { // invalid redeclaration of 'pop()'var stack = Stack<Int>() // variable 'stack' was never mutated; consider changing to 'let' constantprotocol StackProtocol {
associatedtype Element
init()
func push(_ element: Element)
func pop() -> Element?
}
class Stack<Element> {
private var elements: [Element] = []
// MARK: - Lifecycle
init() {}
// MARK: - Public
func push(_ element: Element) {
elements.append(element)
}
func pop() -> Element? {
return elements.popLast()
}
}
extension Stack: StackProtocol {}
// MARK: - Tests
struct TestStack<Element: Equatable>: StackProtocol {
private var elements: [Element] = []
// MARK: - Lifecycle
init() {}
// MARK: - Public
func push(_ element: Element) {
elements.append(element)
}
func pop() -> Element? {
return elements.popLast()
}
}
extension TestStack: Equatable {
static func == (lhs: TestStack<Element>, rhs: TestStack<Element>) -> Bool {
return lhs.elements == rhs.elements
}
}```swift
protocol StackProtocol {
associatedtype Element
init()
func push(_ element: Element)
func pop() -> Element?
}
// Generic stack with push and pop functions.
class Stack<Element> {
private var elements: [Element] = []
// MARK: - Lifecycle
init() {}
// MARK: - Public
func push(_ element: Element) {
elements.append(element)
}
func pop() -> Element? {
return elements.popLast()
}
}
// MARK: - Protocol Conformance
extension Stack: StackProtocol {}
// MARK: - Tests
struct TestStack<Element: Equatable>: StackProtocol {
private var elements: [Element] = []
// MARK: - Lifecycle
init() {}
// MARK: - Public
func push(_ element: Element) {
elements.append(element)
}
func pop() -> Element? {
return elements.popLast()
}
}
extension TestStack: Equatable {
static func == (lhs: TestStack<Element>, rhs: TestStack<Element>) -> Bool {
return lhs.elements == rhs.elements
}
}
let stack = TestStack<Int>()
stack.push(1)
stack.push(2)
stack.push(3)
stack.push(4)
stack.push(5)
stack.push(6)
stack.push(7)
stack.push(8)
stack.push(9)
stack.push(10)
stack.push(11)
stack.push(12)
stack.push(13)
stack.push(14)
stack.push(15)
stack.push(16)
stack.push(17)
stack.push(18)
stack.push(19)
stack.push(20)
stack.push(21)
stack.push(22)
stack.push(23)
stack.push(24)
stack.push(25)
stack.push(26)
stack.push(27)
stack.push(28)
stack.push(29)
stack.push(30)
stack.push(31)
stack.push(32)
stack.push(33)
stack.push(34)
stack.push(35)
stack.push(36)
stack.push(37)
stack.push(38)
stack.push(39)
stack.push(40)
stack.push(41)
stack.push(42)
stack.push(43)
stack.push(44)
stack.push(45)
stack.push(46)
stack.push(47)
stack.push(48)
stack.push(49)
stack.push(50)
stack.push(51)
stack.push(52)
stack.push(53)
stack.push(54)
stack.push(55)
stack.push(56)
stack.push(57)
stack.push(58)
stack.push(59)
stack.push(60)
stack.push(61)
stack.push(62)
stack.push(63)
stack.push(64)
stack.push(65)
stack.push(66)
stack.push(67)
stack.push(68)
stack.push(69)
stack.push(70)
stack.push(71)
stack.push(72)
stack.push(73)
stack.push(74)
stack.push(75)
stack.push(76)
stack.push(77)
stack.push(78)
stack.push(79)
stack.push(80)
stack.push(81)
stack.push(82)
stack.push(83)
stack.push(84)
stack.push(85)
stack.push(86)
stack.push(87)
stack.push(88)
stack.push(89)
stack.push(90)
stack.push(91)
stack.push(92)
stack.push(9extension Stack: StackProtocol {} // initializer requirement 'init()' can only be satisfied by a 'required' initializer in non-final class 'Stack<Element>'elements.append(element) // cannot use mutating member on immutable value: 'self' is immutablereturn elements.popLast() // cannot use mutating member on immutable value: 'self' is immutablevar stack = Stack<Int>() // variable 'stack' was never mutated; consider changing to 'let' constantprotocol StackProtocol {
associatedtype Element
init()
func push(_ element: Element)
func pop() -> Element?
}
class Stack<Element> {
var elements: [Element] = []
// MARK: - push
func push(_ element: Element) {
elements.append(element)
}
// MARK: - pop
func pop() -> Element? {
return elements.popLast()
}
}
extension Stack: StackProtocol {}
// MARK: - StackProtocol
extension StackProtocol {
// MARK: - init
public init() {}
// MARK: - push
public func push(_ element: Element) {
self.push(element)
}
// MARK: - pop
public func pop() -> Element? {
return self.pop()
}
}
extension StackProtocol {
// MARK: - peek
public func peek() -> Element? {
return elements.last
}
}
extension StackProtocol {
// MARK: - isEmpty
public func isEmpty() -> Bool {
return elements.isEmpty
}
}
extension StackProtocol {
// MARK: - count
public var count: Int {
return elements.count
}
}
extension StackProtocol {
// MARK: - clear
public func clear() {
elements.removeAll()
}
}
extension StackProtocol {
// MARK: - remove
public func remove(_ element: Element) -> Bool {
return elements.remove(element)
}
}
extension StackProtocol {
// MARK: - removeFirst
public func removeFirst() -> Element? {
return elements.removeFirst()
}
}
extension StackProtocol {
// MARK: - removeLast
public func removeLast() -> Element? {
return elements.removeLast()
}
}
extension StackProtocol {
// MARK: - removeAll
public func removeAll() {
elements.removeAll()
}
}
extension StackProtocol {
// MARK: - insert
public func insert(_ element: Element, at index: Int) {
elements.insert(element, at: index)
}
}
extension StackProtocol {
// MARK: - append
public func append(_ element: Element) {
elements.append(element)
}
}
extension StackProtocol {
// MARK: - extend
public func extend<T>(_ newElements: T) where T: Collection, T.Element == Element {
elements.append(contentsOf: newElements)
}
}
extension StackProtocol {
// MARK: - reversed
public func reversed() -> Stack<Element> {
return Stack<Element>()
}
}
extension StackProtocol {
// MARK: - map
public func map<U>(_ transform: (Element) throws -> U) rethrows -> [U] {
return try elements.map(transform)
}
}
extension StackProtocol {
// MARK: - reduce
public func reduce<U>(_ initialResult: U, _ transform: (U, Element) throws -> U) rethrows -> U {
return try elements.reduce(initialResult, transform)
}
}
extension StackProtocol {
// MARK: - sorted
public func sorted() -> [Element] {
return elements.sorted()
}
}```swift
protocol StackProtocol {
associatedtype Element
init()
func push(_ element: Element)
func pop() -> Element?
}
// Generic stack with push and pop functions.
class Stack<Element> {
var elements: [Element] = []
// MARK: - push
func push(_ element: Element) {
elements.append(element)
}
// MARK: - pop
func pop() -> Element? {
return elements.popLast()
}
}
// MARK: - StackProtocol
extension Stack: StackProtocol {}
// MARK: - StackProtocol
extension StackProtocol {
// MARK: - init
public init() {}
// MARK: - push
public func push(_ element: Element) {
self.push(element)
}
// MARK: - pop
public func pop() -> Element? {
return self.pop()
}
}
// MARK: - StackProtocol
extension StackProtocol {
// MARK: - peek
public func peek() -> Element? {
return elements.last
}
}
// MARK: - StackProtocol
extension StackProtocol {
// MARK: - isEmpty
public func isEmpty() -> Bool {
return elements.isEmpty
}
}
// MARK: - StackProtocol
extension StackProtocol {
// MARK: - count
public var count: Int {
return elements.count
}
}
// MARK: - StackProtocol
extension StackProtocol {
// MARK: - clear
public func clear() {
elements.removeAll()
}
}
// MARK: - StackProtocol
extension StackProtocol {
// MARK: - remove
public func remove(_ element: Element) -> Bool {
return elements.remove(element)
}
}
// MARK: - StackProtocol
extension StackProtocol {
// MARK: - removeFirst
public func removeFirst() -> Element? {
return elements.removeFirst()
}
}
// MARK: - StackProtocol
extension StackProtocol {
// MARK: - removeLast
public func removeLast() -> Element? {
return elements.removeLast()
}
}
// MARK: - StackProtocol
extension StackProtocol {
// MARK: - removeAll
public func removeAll() {
elements.removeAll()
}
}
// MARK: - StackProtocol
extension StackProtocol {
// MARK: - insert
public func insert(_ element: Element, at index: Int) {
elements.insert(element, at: index)
}
}
// MARK: - StackProtocol
extension StackProtocol {
// MARK: - append
public func append(_ element: Element) {
elements.append(element)
}
}
// MARK: - StackProtocol
extension StackProtocol {
// MARK: - extend
public func extend<T>(_ newElements: T) where T: Collection, T.Element == Element {
elements.append(contentsOf: newElements)
}
}
// MARK: - StackProtocol
extension StackProtocol {
// MARK: - reversed
public func reversed() -> Stack<Element> {
return Stack<Element>()
}
}
// MARK: - StackProtocol
extension StackProtocol {
// MARK: - map
public func map<U>(_ transform: (Element) throws -> U) rethrows -> [U] {
return try elements.map(transform)
}
}
// MARK: - StackProtocol
extension StackProtocol {
// MARK: - reduce
public func reduce<U>(_ initialResult: U, _ transform: (U, Element) throws -> U) rethrows -> U {
return try elements.reduce(initialResult, transform)
}
}
// MARK: - StackProtocol
extension StackProtocol {
// MARK: - sorted
public func sorted() -> [Element] {
return elements.sorted()
}
}
// MARK: - StackProtocol
extension StackProtocol {
// MARK: - sorted(by:)
extension Stack: StackProtocol {} // initializer requirement 'init()' can only be satisfied by a 'required' initializer in non-final class 'Stack<Element>'return elements.last // cannot find 'elements' in scopereturn elements.isEmpty // cannot find 'elements' in scopereturn elements.count // cannot find 'elements' in scopeelements.removeAll() // cannot find 'elements' in scopereturn elements.remove(element) // cannot find 'elements' in scopereturn elements.removeFirst() // cannot find 'elements' in scopereturn elements.removeLast() // cannot find 'elements' in scopeelements.removeAll() // cannot find 'elements' in scopeelements.insert(element, at: index) // cannot find 'elements' in scopeelements.append(element) // cannot find 'elements' in scopeelements.append(contentsOf: newElements) // cannot find 'elements' in scopereturn try elements.map(transform) // cannot find 'elements' in scopereturn try elements.reduce(initialResult, transform) // cannot find 'elements' in scopereturn elements.sorted() // cannot find 'elements' in scopevar stack = Stack<Int>() // variable 'stack' was never mutated; consider changing to 'let' constantprotocol StackProtocol {
associatedtype Element
init()
func push(_ element: Element)
func pop() -> Element?
}
class Stack<Element> {
var elements: [Element] = []
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
init() {}
func push(_ element: Element) {
elements.append(element)
}
func pop() -> Element? {
guard !elements.isEmpty else { return nil }
return elements.popLast()
}
}```swift
protocol StackProtocol {
associatedtype Element
init()
func push(_ element: Element)
func pop() -> Element?
}
// Generic stack with push and pop functions.
class Stack<Element> {
var elements: [Element] = []
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
init() {}
func push(_ element: Element) {
elements.append(element)
}
func pop() -> Element? {
guard !elements.isEmpty else { return nil }
return elements.popLast()
}
}
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifecycle
// MARK: - Public
// MARK: - Lifvar stack = Stack<Int>() // variable 'stack' was never mutated; consider changing to 'let' constantprotocol StackProtocol {
associatedtype Element
init()
func push(_ element: Element)
func pop() -> Element?
}
class Stack<Element> {
private var elements: [Element] = []
// MARK: - Lifecycle
// MARK: - Public
// MARK: Initializer
init() {}
// MARK: - Public
// MARK: Push
func push(_ element: Element) {
elements.append(element)
}
// MARK: Pop
func pop() -> Element? {
guard !elements.isEmpty else { return nil }
return elements.removeLast()
}
}
extension Stack: StackProtocol {}
// MARK: - StackProtocol
extension StackProtocol {
// MARK: - Lifecycle
// MARK: - Public
// MARK: Init
// MARK: - Public
// MARK: Push
// MARK: Pop
}
class Stack<Element> {
private var elements: [Element] = []
// MARK: - Lifecycle
// MARK: - Public
// MARK: Initializer
// MARK: - Public
// MARK: Push
// MARK: Pop
}
struct Stack<Element> {
private var elements: [Element] = []
// MARK: - Lifecycle
// MARK: - Public
// MARK: Initializer
// MARK: - Public
// MARK: Push
// MARK: Pop
}
enum Stack<Element> {
private var elements: [Element] = []
// MARK: - Lifecycle
// MARK: - Public
// MARK: Initializer
// MARK: - Public
// MARK: Push
// MARK: Pop
}```swift
protocol StackProtocol {
associatedtype Element
init()
func push(_ element: Element)
func pop() -> Element?
}
// Generic stack with push and pop functions.
class Stack<Element> {
private var elements: [Element] = []
// MARK: - Lifecycle
// MARK: - Public
// MARK: Initializer
init() {}
// MARK: - Public
// MARK: Push
func push(_ element: Element) {
elements.append(element)
}
// MARK: Pop
func pop() -> Element? {
guard !elements.isEmpty else { return nil }
return elements.removeLast()
}
}
// MARK: - StackProtocol
extension Stack: StackProtocol {}
// MARK: - StackProtocol
extension StackProtocol {
// MARK: - Lifecycle
// MARK: - Public
// MARK: Init
// MARK: - Public
// MARK: Push
// MARK: Pop
}
```
### 2. 泛型类
```swift
protocol StackProtocol {
associatedtype Element
init()
func push(_ element: Element)
func pop() -> Element?
}
// Generic stack with push and pop functions.
class Stack<Element> {
private var elements: [Element] = []
// MARK: - Lifecycle
// MARK: - Public
// MARK: Initializer
// MARK: - Public
// MARK: Push
// MARK: Pop
}
// MARK: - StackProtocol
extension Stack: StackProtocol {}
// MARK: - StackProtocol
extension StackProtocol {
// MARK: - Lifecycle
// MARK: - Public
// MARK: Init
// MARK: - Public
// MARK: Push
// MARK: Pop
}
```
### 3. 泛型结构体
```swift
protocol StackProtocol {
associatedtype Element
init()
func push(_ element: Element)
func pop() -> Element?
}
// Generic stack with push and pop functions.
struct Stack<Element> {
private var elements: [Element] = []
// MARK: - Lifecycle
// MARK: - Public
// MARK: Initializer
// MARK: - Public
// MARK: Push
// MARK: Pop
}
// MARK: - StackProtocol
extension Stack: StackProtocol {}
// MARK: - StackProtocol
extension StackProtocol {
// MARK: - Lifecycle
// MARK: - Public
// MARK: Init
// MARK: - Public
// MARK: Push
// MARK: Pop
}
```
### 4. 泛型枚举
```swift
protocol StackProtocol {
associatedtype Element
init()
func push(_ element: Element)
func pop() -> Element?
}
// Generic stack with push and pop functions.
enum Stack<Element> {
private var elements: [Element] = []
// MARK: - Lifecycle
// MARK: - Public
// MARK: Initializer
// MARK: - Public
// MARK: Push
// MARK: Pop
}
// MARK: - StackProtocol
extension Stack: StackProtocol {}
// MARK: - StackProtocol
extension StackProtocol {
// MARK: - Lifecycle
// MARK: - Public
// MARK: Init
// MARK: - Public
// MARK: Push
// MARK: Pop
}
```
### 5. 泛型协议
```swift
protocol StackProtocol {
associatedtype Element
init()
func push(_ elementextension Stack: StackProtocol {} // 'Stack' is ambiguous for type lookup in this contextclass Stack<Element> { // invalid redeclaration of 'Stack'struct Stack<Element> { // invalid redeclaration of 'Stack'enum Stack<Element> { // invalid redeclaration of 'Stack'private var elements: [Element] = [] // enums must not contain stored propertiesvar stack = Stack<Int>() // variable 'stack' was never mutated; consider changing to 'let' constantprotocol StackProtocol {
associatedtype Element
init()
func push(_ element: Element)
func pop() -> Element?
}
class Stack<Element> {
private var elements: [Element] = []
// MARK: - Lifecycle
init() {}
// MARK: - Public
func push(_ element: Element) {
elements.append(element)
}
func pop() -> Element? {
return elements.popLast()
}
}
extension Stack: StackProtocol {}
// MARK: - Private
extension Stack {
private func peek() -> Element? {
return elements.last
}
}```swift
protocol StackProtocol {
associatedtype Element
init()
func push(_ element: Element)
func pop() -> Element?
}
// Generic stack with push and pop functions.
class Stack<Element> {
private var elements: [Element] = []
// MARK: - Lifecycle
init() {}
// MARK: - Public
func push(_ element: Element) {
elements.append(element)
}
func pop() -> Element? {
return elements.popLast()
}
}
// MARK: - Protocol Conformance
extension Stack: StackProtocol {}
// MARK: - Private
extension Stack {
private func peek() -> Element? {
return elements.last
}
}
// MARK: - Example
let stack = Stack<Int>()
stack.push(1)
stack.push(2)
stack.push(3)
print(stack.peek()) // prints 3
stack.pop() // returns 3
print(stack.peek()) // prints 2
stack.pop() // returns 2
stack.pop() // returns 1
stack.pop() // returns nil
```
### 2. 泛型嵌套类
```swift
protocol StackProtocol {
associatedtype Element
init()
func push(_ element: Element)
func pop() -> Element?
}
// Generic stack with push and pop functions.
class Stack<Element> {
private var elements: [Element] = []
// MARK: - Lifecycle
init() {}
// MARK: - Public
func push(_ element: Element) {
elements.append(element)
}
func pop() -> Element? {
return elements.popLast()
}
}
// MARK: - Protocol Conformance
extension Stack: StackProtocol {}
// MARK: - Private
extension Stack {
private func peek() -> Element? {
return elements.last
}
}
// MARK: - Example
let stack = Stack<Int>()
stack.push(1)
stack.push(2)
stack.push(3)
print(stack.peek()) // prints 3
stack.pop() // returns 3
print(stack.peek()) // prints 2
stack.pop() // returns 2
stack.pop() // returns 1
stack.pop() // returns nil
```
### 3. 泛型嵌套类 + 泛型嵌套协议
```swift
protocol StackProtocol {
associatedtype Element
init()
func push(_ element: Element)
func pop() -> Element?
}
// Generic stack with push and pop functions.
class Stack<Element> {
private var elements: [Element] = []
// MARK: - Lifecycle
init() {}
// MARK: - Public
func push(_ element: Element) {
elements.append(element)
}
func pop() -> Element? {
return elements.popLast()
}
}
// MARK: - Protocol Conformance
extension Stack: StackProtocol {}
// MARK: - Private
extension Stack {
private func peek() -> Element? {
return elements.last
}
}
// MARK: - Example
let stack = Stack<Int>()
stack.push(1)
stack.push(2)
stack.push(3)
print(stack.peek()) // prints 3
stack.pop() // returns 3
print(stack.peek()) // prints 2
stack.pop() // returns 2
stack.pop() // returns 1
stack.pop() // returns nil
```
### 4. 泛型嵌套类 + 泛型嵌套协议 + 泛型嵌套嵌套类
```swift
protocol StackProtocol {
associatedtype Element
init()
func push(_ element: Element)
func pop() -> Element?
}
// Generic stack with push and pop functions.
class Stack<Element> {
private var elements: [Element] = []
// MARK: - Lifecycle
init() {}
// MARK: - Public
extension Stack: StackProtocol {} // initializer requirement 'init()' can only be satisfied by a 'required' initializer in non-final class 'Stack<Element>'var stack = Stack<Int>() // variable 'stack' was never mutated; consider changing to 'let' constantprotocol StackProtocol {
associatedtype Element
init()
func push(_ element: Element)
func pop() -> Element?
}
class Stack<Element> {
var elements: [Element] = []
// MARK: - Push
func push(_ element: Element) {
elements.append(element)
}
// MARK: - Pop
func pop() -> Element? {
guard !elements.isEmpty else { return nil }
return elements.popLast()
}
}```swift
protocol StackProtocol {
associatedtype Element
init()
func push(_ element: Element)
func pop() -> Element?
}
// Generic stack with push and pop functions.
class Stack<Element> {
var elements: [Element] = []
// MARK: - Push
func push(_ element: Element) {
elements.append(element)
}
// MARK: - Pop
func pop() -> Element? {
guard !elements.isEmpty else { return nil }
return elements.popLast()
}
}
// MARK: - Protocol Conformance
extension Stack: StackProtocol {}
// MARK: - Example
let stack = Stack<Int>()
stack.push(1)
stack.push(2)
stack.push(3)
stack.push(4)
stack.push(5)
stack.push(6)
stack.push(7)
stack.push(8)
stack.push(9)
stack.push(10)
stack.push(11)
stack.push(12)
stack.push(13)
stack.push(14)
stack.push(15)
stack.push(16)
stack.push(17)
stack.push(18)
stack.push(19)
stack.push(20)
stack.push(21)
stack.push(22)
stack.push(23)
stack.push(24)
stack.push(25)
stack.push(26)
stack.push(27)
stack.push(28)
stack.push(29)
stack.push(30)
stack.push(31)
stack.push(32)
stack.push(33)
stack.push(34)
stack.push(35)
stack.push(36)
stack.push(37)
stack.push(38)
stack.push(39)
stack.push(40)
stack.push(41)
stack.push(42)
stack.push(43)
stack.push(44)
stack.push(45)
stack.push(46)
stack.push(47)
stack.push(48)
stack.push(49)
stack.push(50)
stack.push(51)
stack.push(52)
stack.push(53)
stack.push(54)
stack.push(55)
stack.push(56)
stack.push(57)
stack.push(58)
stack.push(59)
stack.push(60)
stack.push(61)
stack.push(62)
stack.push(63)
stack.push(64)
stack.push(65)
stack.push(66)
stack.push(67)
stack.push(68)
stack.push(69)
stack.push(70)
stack.push(71)
stack.push(72)
stack.push(73)
stack.push(74)
stack.push(75)
stack.push(76)
stack.push(77)
stack.push(78)
stack.push(79)
stack.push(80)
stack.push(81)
stack.push(82)
stack.push(83)
stack.push(84)
stack.push(85)
stack.push(86)
stack.push(87)
stack.push(88)
stack.push(89)
stack.push(90)
stack.push(91)
stack.push(92)
stack.push(93)
stack.push(94)
stack.push(95)
stack.push(96)
stack.push(97)
stack.push(98)
stack.push(99)
stack.push(100)
stack.push(101)
stack.push(102)
stack.push(103)
stack.push(104)
stack.push(105)
stack.push(106)
stack.push(107)
stack.push(108)
stack.push(109)
stack.push(110)
stack.push(111var stack = Stack<Int>() // variable 'stack' was never mutated; consider changing to 'let' constantprotocol CacheProtocol {
associatedtype Key: Hashable
associatedtype Element
init(capacity: Int)
subscript(key: Key) -> Element? { get set }
}
class Cache<Key: Hashable, Element>: CacheProtocol {
private var capacity: Int
private var map: [Key: Element]
private var queue: [Key]
init(capacity: Int) {
self.capacity = capacity
self.map = [Key: Element]()
self.queue = [Key]()
}
subscript(key: Key) -> Element? {
get {
return map[key]
}
set {
if let element = map[key] {
queue.removeFirst()
queue.append(key)
map[key] = element
} else {
if map.count == capacity {
let lastKey = queue.removeLast()
map.removeValue(forKey: lastKey)
}
map[key] = newValue
queue.append(key)
}
}
}
}```swift
protocol CacheProtocol {
associatedtype Key: Hashable
associatedtype Element
init(capacity: Int)
subscript(key: Key) -> Element? { get set }
}
// Generic in-memory cache that follows to the LRU (Least Recently Used) eviction policy.
// The cache should have a specified capacity limit, and when this limit is reached, it should remove the least recently used item to make space for new entries.
class Cache<Key: Hashable, Element>: CacheProtocol {
private var capacity: Int
private var map: [Key: Element]
private var queue: [Key]
init(capacity: Int) {
self.capacity = capacity
self.map = [Key: Element]()
self.queue = [Key]()
}
subscript(key: Key) -> Element? {
get {
return map[key]
}
set {
if let element = map[key] {
queue.removeFirst()
queue.append(key)
map[key] = element
} else {
if map.count == capacity {
let lastKey = queue.removeLast()
map.removeValue(forKey: lastKey)
}
map[key] = newValue
queue.append(key)
}
}
}
}
```init(capacity: Int) { // initializer requirement 'init(capacity:)' can only be satisfied by a 'required' initializer in non-final class 'Cache<Key, Element>'protocol CacheProtocol {
associatedtype Key: Hashable
associatedtype Element
init(capacity: Int)
subscript(key: Key) -> Element? { get set }
}
class Cache<Key: Hashable, Element>: CacheProtocol {
private var capacity: Int
private var map: [Key: Element] = [:]
private var queue: [Key] = []
init(capacity: Int) {
self.capacity = capacity
}
subscript(key: Key) -> Element? {
get {
return map[key]
}
set {
if let element = map[key] {
queue.removeFirst()
queue.append(key)
map[key] = element
} else {
if map.count == capacity {
let key = queue.removeLast()
map.removeValue(forKey: key)
}
queue.insert(key, at: 0)
map[key] = newValue
}
}
}
}```swift
protocol CacheProtocol {
associatedtype Key: Hashable
associatedtype Element
init(capacity: Int)
subscript(key: Key) -> Element? { get set }
}
// Generic in-memory cache that follows to the LRU (Least Recently Used) eviction policy.
// The cache should have a specified capacity limit, and when this limit is reached, it should remove the least recently used item to make space for new entries.
class Cache<Key: Hashable, Element>: CacheProtocol {
private var capacity: Int
private var map: [Key: Element] = [:]
private var queue: [Key] = []
init(capacity: Int) {
self.capacity = capacity
}
subscript(key: Key) -> Element? {
get {
return map[key]
}
set {
if let element = map[key] {
queue.removeFirst()
queue.append(key)
map[key] = element
} else {
if map.count == capacity {
let key = queue.removeLast()
map.removeValue(forKey: key)
}
queue.insert(key, at: 0)
map[key] = newValue
}
}
}
}
// Your Cache object will be instantiated and called as such:
// let obj = Cache(capacity: capacity)
// let ret_1: Int = obj[key]!
// obj[key] = value
```init(capacity: Int) { // initializer requirement 'init(capacity:)' can only be satisfied by a 'required' initializer in non-final class 'Cache<Key, Element>'protocol CacheProtocol {
associatedtype Key: Hashable
associatedtype Element
init(capacity: Int)
subscript(key: Key) -> Element? { get set }
}
class Cache<Key: Hashable, Element>: CacheProtocol {
private var capacity: Int
private var elements: [Key: Element]
private var queue: [Key]
init(capacity: Int) {
self.capacity = capacity
self.elements = [:]
self.queue = []
}
subscript(key: Key) -> Element? {
get {
return elements[key]
}
set {
if let element = newValue {
elements[key] = element
queue.append(key)
evictIfNeeded()
}
}
}
private mutating func evictIfNeeded() {
if queue.count > capacity {
let key = queue.removeFirst()
elements[key] = nil
}
}
}```swift
protocol CacheProtocol {
associatedtype Key: Hashable
associatedtype Element
init(capacity: Int)
subscript(key: Key) -> Element? { get set }
}
// Generic in-memory cache that follows to the LRU (Least Recently Used) eviction policy.
// The cache should have a specified capacity limit, and when this limit is reached, it should remove the least recently used item to make space for new entries.
class Cache<Key: Hashable, Element>: CacheProtocol {
private var capacity: Int
private var elements: [Key: Element]
private var queue: [Key]
init(capacity: Int) {
self.capacity = capacity
self.elements = [:]
self.queue = []
}
subscript(key: Key) -> Element? {
get {
return elements[key]
}
set {
if let element = newValue {
elements[key] = element
queue.append(key)
evictIfNeeded()
}
}
}
private mutating func evictIfNeeded() {
if queue.count > capacity {
let key = queue.removeFirst()
elements[key] = nil
}
}
}
```init(capacity: Int) { // initializer requirement 'init(capacity:)' can only be satisfied by a 'required' initializer in non-final class 'Cache<Key, Element>'private mutating func evictIfNeeded() { // 'mutating' is not valid on instance methods in classesprotocol CacheProtocol {
associatedtype Key: Hashable
associatedtype Element
init(capacity: Int)
subscript(key: Key) -> Element? { get set }
}
class Cache<Key: Hashable, Element>: CacheProtocol {
private var capacity: Int
private var map: [Key: Element]
private var queue: [Key]
init(capacity: Int) {
self.capacity = capacity
self.map = [Key: Element]()
self.queue = [Key]()
}
subscript(key: Key) -> Element? {
get {
return map[key]
}
set {
if let element = map[key] {
queue.removeFirst()
queue.append(key)
map[key] = element
} else {
if map.count == capacity {
map.removeValue(forKey: queue.removeLast())
}
queue.append(key)
map[key] = newValue
}
}
}
}```swift
protocol CacheProtocol {
associatedtype Key: Hashable
associatedtype Element
init(capacity: Int)
subscript(key: Key) -> Element? { get set }
}
// Generic in-memory cache that follows to the LRU (Least Recently Used) eviction policy.
// The cache should have a specified capacity limit, and when this limit is reached, it should remove the least recently used item to make space for new entries.
class Cache<Key: Hashable, Element>: CacheProtocol {
private var capacity: Int
private var map: [Key: Element]
private var queue: [Key]
init(capacity: Int) {
self.capacity = capacity
self.map = [Key: Element]()
self.queue = [Key]()
}
subscript(key: Key) -> Element? {
get {
return map[key]
}
set {
if let element = map[key] {
queue.removeFirst()
queue.append(key)
map[key] = element
} else {
if map.count == capacity {
map.removeValue(forKey: queue.removeLast())
}
queue.append(key)
map[key] = newValue
}
}
}
}
```init(capacity: Int) { // initializer requirement 'init(capacity:)' can only be satisfied by a 'required' initializer in non-final class 'Cache<Key, Element>'protocol CacheProtocol {
associatedtype Key: Hashable
associatedtype Element
init(capacity: Int)
subscript(key: Key) -> Element? { get set }
}
class Cache<Key: Hashable, Element>: CacheProtocol {
private var capacity: Int
private var cache: [Key: Element] = [:]
private var order: [Key] = []
init(capacity: Int) {
self.capacity = capacity
}
subscript(key: Key) -> Element? {
get {
return cache[key]
}
set {
if let element = newValue {
cache[key] = element
order.append(key)
evict()
}
}
}
private func evict() {
while order.count > capacity {
let key = order.removeFirst()
cache.removeValue(forKey: key)
}
}
}```swift
protocol CacheProtocol {
associatedtype Key: Hashable
associatedtype Element
init(capacity: Int)
subscript(key: Key) -> Element? { get set }
}
// Generic in-memory cache that follows to the LRU (Least Recently Used) eviction policy.
// The cache should have a specified capacity limit, and when this limit is reached, it should remove the least recently used item to make space for new entries.
class Cache<Key: Hashable, Element>: CacheProtocol {
private var capacity: Int
private var cache: [Key: Element] = [:]
private var order: [Key] = []
init(capacity: Int) {
self.capacity = capacity
}
subscript(key: Key) -> Element? {
get {
return cache[key]
}
set {
if let element = newValue {
cache[key] = element
order.append(key)
evict()
}
}
}
private func evict() {
while order.count > capacity {
let key = order.removeFirst()
cache.removeValue(forKey: key)
}
}
}
// Your Cache object will be instantiated and called as such:
// let obj = Cache(capacity: capacity)
// let ret_1: Int = obj.get(key)
// obj.put(key, value)
```init(capacity: Int) { // initializer requirement 'init(capacity:)' can only be satisfied by a 'required' initializer in non-final class 'Cache<Key, Element>'protocol CacheProtocol {
associatedtype Key: Hashable
associatedtype Element
init(capacity: Int)
subscript(key: Key) -> Element? { get set }
}
class Cache<Key: Hashable, Element>: CacheProtocol {
private var capacity: Int
private var map: [Key: Element]
private var queue: [Key]
init(capacity: Int) {
self.capacity = capacity
self.map = [Key: Element]()
self.queue = [Key]()
}
subscript(key: Key) -> Element? {
get {
return map[key]
}
set {
if let element = map[key] {
queue.remove(element)
}
map[key] = newValue
queue.append(key)
evict()
}
}
private func evict() {
while map.count > capacity {
let key = queue.removeFirst()
map[key] = nil
}
}
}```swift
protocol CacheProtocol {
associatedtype Key: Hashable
associatedtype Element
init(capacity: Int)
subscript(key: Key) -> Element? { get set }
}
// Generic in-memory cache that follows to the LRU (Least Recently Used) eviction policy.
// The cache should have a specified capacity limit, and when this limit is reached, it should remove the least recently used item to make space for new entries.
class Cache<Key: Hashable, Element>: CacheProtocol {
private var capacity: Int
private var map: [Key: Element]
private var queue: [Key]
init(capacity: Int) {
self.capacity = capacity
self.map = [Key: Element]()
self.queue = [Key]()
}
subscript(key: Key) -> Element? {
get {
return map[key]
}
set {
if let element = map[key] {
queue.remove(element)
}
map[key] = newValue
queue.append(key)
evict()
}
}
private func evict() {
while map.count > capacity {
let key = queue.removeFirst()
map[key] = nil
}
}
}
// Your Cache object will be instantiated and called as such:
// let obj = Cache(capacity: capacity)
// obj[key] = value
```init(capacity: Int) { // initializer requirement 'init(capacity:)' can only be satisfied by a 'required' initializer in non-final class 'Cache<Key, Element>'queue.remove(element) // no exact matches in call to instance method 'remove'protocol CacheProtocol {
associatedtype Key: Hashable
associatedtype Element
init(capacity: Int)
subscript(key: Key) -> Element? { get set }
}
class Cache<Key: Hashable, Element>: CacheProtocol {
private var capacity: Int
private var map: [Key: Element] = [:]
private var queue: [Key] = []
init(capacity: Int) {
self.capacity = capacity
}
subscript(key: Key) -> Element? {
get {
return map[key]
}
set {
if let element = map[key] {
queue.removeFirst()
queue.append(key)
map[key] = element
} else {
map[key] = newValue
queue.append(key)
}
evict()
}
}
private func evict() {
while queue.count > capacity {
map.removeValue(forKey: queue.removeFirst())
}
}
}```swift
protocol CacheProtocol {
associatedtype Key: Hashable
associatedtype Element
init(capacity: Int)
subscript(key: Key) -> Element? { get set }
}
// Generic in-memory cache that follows to the LRU (Least Recently Used) eviction policy.
// The cache should have a specified capacity limit, and when this limit is reached, it should remove the least recently used item to make space for new entries.
class Cache<Key: Hashable, Element>: CacheProtocol {
private var capacity: Int
private var map: [Key: Element] = [:]
private var queue: [Key] = []
init(capacity: Int) {
self.capacity = capacity
}
subscript(key: Key) -> Element? {
get {
return map[key]
}
set {
if let element = map[key] {
queue.removeFirst()
queue.append(key)
map[key] = element
} else {
map[key] = newValue
queue.append(key)
}
evict()
}
}
private func evict() {
while queue.count > capacity {
map.removeValue(forKey: queue.removeFirst())
}
}
}
// Your Cache object will be instantiated and called as such:
// let obj = Cache(capacity: capacity)
// let ret_1: Int = obj.get(key)
// obj.put(key, value)
```init(capacity: Int) { // initializer requirement 'init(capacity:)' can only be satisfied by a 'required' initializer in non-final class 'Cache<Key, Element>'protocol CacheProtocol {
associatedtype Key: Hashable
associatedtype Element
init(capacity: Int)
subscript(key: Key) -> Element? { get set }
}
class Cache<Key: Hashable, Element>: CacheProtocol {
private var capacity: Int
private var map: [Key: Element] = [:]
private var queue: [Key] = []
init(capacity: Int) {
self.capacity = capacity
}
subscript(key: Key) -> Element? {
get {
return map[key]
}
set {
if let element = map[key] {
queue.removeFirst()
queue.append(key)
map[key] = element
} else {
if map.count == capacity {
let last = queue.removeLast()
map.removeValue(forKey: last)
}
queue.insert(key, at: 0)
map[key] = newValue
}
}
}
}```swift
protocol CacheProtocol {
associatedtype Key: Hashable
associatedtype Element
init(capacity: Int)
subscript(key: Key) -> Element? { get set }
}
// Generic in-memory cache that follows to the LRU (Least Recently Used) eviction policy.
// The cache should have a specified capacity limit, and when this limit is reached, it should remove the least recently used item to make space for new entries.
class Cache<Key: Hashable, Element>: CacheProtocol {
private var capacity: Int
private var map: [Key: Element] = [:]
private var queue: [Key] = []
init(capacity: Int) {
self.capacity = capacity
}
subscript(key: Key) -> Element? {
get {
return map[key]
}
set {
if let element = map[key] {
queue.removeFirst()
queue.append(key)
map[key] = element
} else {
if map.count == capacity {
let last = queue.removeLast()
map.removeValue(forKey: last)
}
queue.insert(key, at: 0)
map[key] = newValue
}
}
}
}
// Your Cache object will be instantiated and called as such:
// let obj = Cache(capacity: capacity)
// let ret_1: Int = obj[key]!
// obj[key] = value
```init(capacity: Int) { // initializer requirement 'init(capacity:)' can only be satisfied by a 'required' initializer in non-final class 'Cache<Key, Element>'protocol CacheProtocol {
associatedtype Key: Hashable
associatedtype Element
init(capacity: Int)
subscript(key: Key) -> Element? { get set }
}
class Cache<Key: Hashable, Element>: CacheProtocol {
private var capacity: Int
private var map: [Key: Element]
private var queue: [Key]
init(capacity: Int) {
self.capacity = capacity
self.map = [Key: Element]()
self.queue = [Key]()
}
subscript(key: Key) -> Element? {
get {
return map[key]
}
set {
if let element = map[key] {
queue.remove(element)
queue.append(key)
map[key] = newValue
} else {
if queue.count == capacity {
map[queue.removeFirst()] = nil
}
queue.append(key)
map[key] = newValue
}
}
}
}```swift
protocol CacheProtocol {
associatedtype Key: Hashable
associatedtype Element
init(capacity: Int)
subscript(key: Key) -> Element? { get set }
}
// Generic in-memory cache that follows to the LRU (Least Recently Used) eviction policy.
// The cache should have a specified capacity limit, and when this limit is reached, it should remove the least recently used item to make space for new entries.
class Cache<Key: Hashable, Element>: CacheProtocol {
private var capacity: Int
private var map: [Key: Element]
private var queue: [Key]
init(capacity: Int) {
self.capacity = capacity
self.map = [Key: Element]()
self.queue = [Key]()
}
subscript(key: Key) -> Element? {
get {
return map[key]
}
set {
if let element = map[key] {
queue.remove(element)
queue.append(key)
map[key] = newValue
} else {
if queue.count == capacity {
map[queue.removeFirst()] = nil
}
queue.append(key)
map[key] = newValue
}
}
}
}
```init(capacity: Int) { // initializer requirement 'init(capacity:)' can only be satisfied by a 'required' initializer in non-final class 'Cache<Key, Element>'queue.remove(element) // no exact matches in call to instance method 'remove'protocol CacheProtocol {
associatedtype Key: Hashable
associatedtype Element
init(capacity: Int)
subscript(key: Key) -> Element? { get set }
}
class Cache<Key: Hashable, Element>: CacheProtocol {
private var capacity: Int
private var map: [Key: Element] = [:]
private var queue: [Key] = []
init(capacity: Int) {
self.capacity = capacity
}
subscript(key: Key) -> Element? {
get {
return map[key]
}
set {
if let element = newValue {
update(key: key, element: element)
} else {
remove(key: key)
}
}
}
func update(key: Key, element: Element) {
remove(key: key)
insert(key: key, element: element)
}
func remove(key: Key) {
if let index = queue.firstIndex(of: key) {
queue.remove(at: index)
map.removeValue(forKey: key)
}
}
func insert(key: Key, element: Element) {
if map[key] != nil {
return
}
if queue.count == capacity {
remove(key: queue.removeFirst())
}
map[key] = element
queue.append(key)
}
}```swift
protocol CacheProtocol {
associatedtype Key: Hashable
associatedtype Element
init(capacity: Int)
subscript(key: Key) -> Element? { get set }
}
// Generic in-memory cache that follows to the LRU (Least Recently Used) eviction policy.
// The cache should have a specified capacity limit, and when this limit is reached, it should remove the least recently used item to make space for new entries.
class Cache<Key: Hashable, Element>: CacheProtocol {
private var capacity: Int
private var map: [Key: Element] = [:]
private var queue: [Key] = []
init(capacity: Int) {
self.capacity = capacity
}
subscript(key: Key) -> Element? {
get {
return map[key]
}
set {
if let element = newValue {
update(key: key, element: element)
} else {
remove(key: key)
}
}
}
func update(key: Key, element: Element) {
remove(key: key)
insert(key: key, element: element)
}
func remove(key: Key) {
if let index = queue.firstIndex(of: key) {
queue.remove(at: index)
map.removeValue(forKey: key)
}
}
func insert(key: Key, element: Element) {
if map[key] != nil {
return
}
if queue.count == capacity {
remove(key: queue.removeFirst())
}
map[key] = element
queue.append(key)
}
}
// Your LRUCache object will be instantiated and called as such:
// let obj = LRUCache(capacity)
// let ret_1: Int = obj.get(key)
// obj.put(key, value)
```init(capacity: Int) { // initializer requirement 'init(capacity:)' can only be satisfied by a 'required' initializer in non-final class 'Cache<Key, Element>'protocol ExpirableCacheProtocol {
associatedtype Key: Hashable
associatedtype Value
func put(value: Value, key: Key, expiration: TimeInterval)
func get(key: Key) -> Value?
}
class ExpirableCache<Key: Hashable, Value> {
private var cache: [Key: (value: Value, expiration: Date)] = [:]
private let expirationPolicy: ExpirationPolicy<Key>
init(expirationPolicy: ExpirationPolicy<Key>) {
self.expirationPolicy = expirationPolicy
}
subscript(key: Key) -> Value? {
get(key: key)
}
func put(value: Value, key: Key, expiration: TimeInterval) {
expirationPolicy.put(value: value, key: key, expiration: expiration)
}
func get(key: Key) -> Value? {
guard let (value, expiration) = cache[key] else { return nil }
guard expiration > Date() else {
cache.removeValue(forKey: key)
return nil
}
return value
}
}
typealias ExpirationPolicy<Key: Hashable> = (value: Value, key: Key, expiration: Date) -> Date
class TimeIntervalExpirationPolicy<Key: Hashable>: ExpirationPolicy<Key> {
private let interval: TimeInterval
init(interval: TimeInterval) {
self.interval = interval
}
func put(value: Value, key: Key, expiration: TimeInterval) {
cache[key] = (value, Date(timeIntervalSinceNow: expiration))
}
}
class LRUCache<Key: Hashable, Value> {
private var cache: [Key: Value] = [:]
private let capacity: Int
private var accessOrder: [Key] = []
init(capacity: Int) {
self.capacity = capacity
}
subscript(key: Key) -> Value? {
get(key: key)
}
func put(value: Value, key: Key) {
if cache[key] != nil {
cache[key] = value
return
}
if cache.count == capacity {
cache.removeValue(forKey: accessOrder.removeLast())
}
cache[key] = value
accessOrder.insert(key, at: 0)
}
func get(key: Key) -> Value? {
guard let value = cache[key] else { return nil }
cache.removeValue(forKey: key)
cache[key] = value
accessOrder.removeFirst()
accessOrder.insert(key, at: 0)
return value
}
}```swift
protocol ExpirableCacheProtocol {
associatedtype Key: Hashable
associatedtype Value
func put(value: Value, key: Key, expiration: TimeInterval)
func get(key: Key) -> Value?
}
// Caching mechanism with expiration eviction policy.
// Subscript methods used for convenient access.
class ExpirableCache<Key: Hashable, Value> {
private var cache: [Key: (value: Value, expiration: Date)] = [:]
private let expirationPolicy: ExpirationPolicy<Key>
init(expirationPolicy: ExpirationPolicy<Key>) {
self.expirationPolicy = expirationPolicy
}
subscript(key: Key) -> Value? {
get(key: key)
}
func put(value: Value, key: Key, expiration: TimeInterval) {
expirationPolicy.put(value: value, key: key, expiration: expiration)
}
func get(key: Key) -> Value? {
guard let (value, expiration) = cache[key] else { return nil }
guard expiration > Date() else {
cache.removeValue(forKey: key)
return nil
}
return value
}
}
// Expiration policy for the cache.
// Expiration policy is a function that takes a key and value, and returns
// the expiration date for the given key and value.
// The expiration date is the date when the key and value should be evicted
// from the cache.
typealias ExpirationPolicy<Key: Hashable> = (value: Value, key: Key, expiration: Date) -> Date
// Expiration policy that uses the given time interval.
class TimeIntervalExpirationPolicy<Key: Hashable>: ExpirationPolicy<Key> {
private let interval: TimeInterval
init(interval: TimeInterval) {
self.interval = interval
}
func put(value: Value, key: Key, expiration: TimeInterval) {
cache[key] = (value, Date(timeIntervalSinceNow: expiration))
}
}
```
### 解法二：LRU缓存
LRU缓存是一种缓存淘汰策略，当缓存满时，将最近最少使用的缓存移除。
```swift
class LRUCache<Key: Hashable, Value> {
private var cache: [Key: Value] = [:]
private let capacity: Int
private var accessOrder: [Key] = []
init(capacity: Int) {
self.capacity = capacity
}
subscript(key: Key) -> Value? {
get(key: key)
}
func put(value: Value, key: Key) {
if cache[key] != nil {
cache[key] = value
return
}
if cache.count == capacity {
cache.removeValue(forKey: accessOrder.removeLast())
}
cache[key] = value
accessOrder.insert(key, at: 0)
}
func get(key: Key) -> Value? {
guard let value = cache[key] else { return nil }
cache.removeValue(forKey: key)
cache[key] = value
accessOrder.removeFirst()
accessOrder.insert(key, at: 0)
return value
}
}
```
### 解法三：LRU缓存 + 双向链表
LRU缓存是一种缓存淘汰策略，当缓存满时，将最近最少使用的缓存移除。
双向链表是一种数据结构，可以方便的从链表头尾增删元素，并且可以在链表中任意位置插入和删除元素。
```swift
class LRUCache<Key: Hashable, Value> {
private var capacity: Int
private var cache: [Key: Node] = [:]
private var head: Node = Node()
private var tail: Node = Node()
init(capacity: Int) {
self.capacity = capacity
head.next = tail
tail.prev = head
}
subscript(key: Key) -> Value? {
get(key: key)
}
func put(value: Value, key: Key) {
guard cache[key] == nil else { return }
if cache.count == capacity {
removeLRU()
}
let node = Node(key: key, value: value)
cache[key] = node
addget(key: key) // expected '{' to start getter definitiontypealias ExpirationPolicy<Key: Hashable> = (value: Value, key: Key, expiration: Date) -> Date // cannot find type 'Value' in scopetypealias ExpirationPolicy<Key: Hashable> = (value: Value, key: Key, expiration: Date) -> Date // function types cannot have argument labels; use '_' before 'expiration'typealias ExpirationPolicy<Key: Hashable> = (value: Value, key: Key, expiration: Date) -> Date // function types cannot have argument labels; use '_' before 'value'typealias ExpirationPolicy<Key: Hashable> = (value: Value, key: Key, expiration: Date) -> Date // function types cannot have argument labels; use '_' before 'key'func put(value: Value, key: Key, expiration: TimeInterval) { // cannot find type 'Value' in scopecache[key] = (value, Date(timeIntervalSinceNow: expiration)) // cannot find 'cache' in scopeget(key: key) // expected '{' to start getter definitionThread.sleep(forTimeInterval: 1.1) // class method 'sleep' is unavailable from asynchronous contexts; Use Task.sleep(until:clock:) instead.; this is an error in Swift 6Thread.sleep(forTimeInterval: 0.9) // class method 'sleep' is unavailable from asynchronous contexts; Use Task.sleep(until:clock:) instead.; this is an error in Swift 6protocol ExpirableCacheProtocol {
associatedtype Key: Hashable
associatedtype Value
func put(value: Value, key: Key, expiration: TimeInterval)
func get(key: Key) -> Value?
}
class ExpirableCache<Key: Hashable, Value> {
private let cache: [Key: (value: Value, expiration: Date)]
private let expiration: TimeInterval
init(expiration: TimeInterval) {
self.expiration = expiration
self.cache = [:]
}
subscript(key: Key) -> Value? {
get(key: key)
}
func put(value: Value, key: Key, expiration: TimeInterval) {
cache[key] = (value, Date(timeIntervalSinceNow: expiration))
}
func get(key: Key) -> Value? {
guard let (value, expiration) = cache[key] else {
return nil
}
if expiration < Date() {
cache[key] = nil
return nil
}
return value
}
}
class LRUCache<Key: Hashable, Value> {
private let capacity: Int
private var cache: [Key: Value]
private var accessOrder: [Key]
init(capacity: Int) {
self.capacity = capacity
self.cache = [:]
self.accessOrder = []
}
subscript(key: Key) -> Value? {
get(key: key)
}
func get(key: Key) -> Value? {
guard let value = cache[key] else {
return nil
}
// Move the key to the end of the access order list.
accessOrder.remove(key)
accessOrder.append(key)
return value
}
func put(value: Value, key: Key) {
guard let _ = cache[key] else {
// Add the key to the cache.
cache[key] = value
// Add the key to the access order list.
accessOrder.append(key)
// If the cache is full, remove the first (least recently used) key.
if cache.count > capacity {
let first = accessOrder.removeFirst()
cache.removeValue(forKey: first)
}
return
}
// Update the value for the key.
cache[key] = value
// Move the key to the end of the access order list.
accessOrder.remove(key)
accessOrder.append(key)
}
}```swift
protocol ExpirableCacheProtocol {
associatedtype Key: Hashable
associatedtype Value
func put(value: Value, key: Key, expiration: TimeInterval)
func get(key: Key) -> Value?
}
// Caching mechanism with expiration eviction policy.
// Subscript methods used for convenient access.
class ExpirableCache<Key: Hashable, Value> {
private let cache: [Key: (value: Value, expiration: Date)]
private let expiration: TimeInterval
init(expiration: TimeInterval) {
self.expiration = expiration
self.cache = [:]
}
subscript(key: Key) -> Value? {
get(key: key)
}
func put(value: Value, key: Key, expiration: TimeInterval) {
cache[key] = (value, Date(timeIntervalSinceNow: expiration))
}
func get(key: Key) -> Value? {
guard let (value, expiration) = cache[key] else {
return nil
}
if expiration < Date() {
cache[key] = nil
return nil
}
return value
}
}
```
### 2. 实现一个 `LRUCache` 类
```swift
class LRUCache<Key: Hashable, Value> {
private let capacity: Int
private var cache: [Key: Value]
private var accessOrder: [Key]
init(capacity: Int) {
self.capacity = capacity
self.cache = [:]
self.accessOrder = []
}
subscript(key: Key) -> Value? {
get(key: key)
}
func get(key: Key) -> Value? {
guard let value = cache[key] else {
return nil
}
// Move the key to the end of the access order list.
accessOrder.remove(key)
accessOrder.append(key)
return value
}
func put(value: Value, key: Key) {
guard let _ = cache[key] else {
// Add the key to the cache.
cache[key] = value
// Add the key to the access order list.
accessOrder.append(key)
// If the cache is full, remove the first (least recently used) key.
if cache.count > capacity {
let first = accessOrder.removeFirst()
cache.removeValue(forKey: first)
}
return
}
// Update the value for the key.
cache[key] = value
// Move the key to the end of the access order list.
accessOrder.remove(key)
accessOrder.append(key)
}
}
```
### 3. 测试
```swift
let cache = LRUCache(capacity: 2)
cache.put(value: 1, key: 1)
cache.put(value: 2, key: 2)
cache.put(value: 3, key: 3)
print(cache[1]) // 1
print(cache[2]) // 2
print(cache[3]) // 3
cache.put(value: 4, key: 4)
print(cache[1]) // nil
print(cache[2]) // 2
print(cache[3]) // 3
print(cache[4]) // 4
```
### 4. 参考
- [LRU Cache - LeetCode](https://leetcode.com/problems/lru-cache/)
- [Swift 实现 LRU Cache](https://www.jianshu.com/p/485385b65b54)
- [Swift 实现 LRU Cache](https://www.jianshu.com/p/485385b65b54)
- [Swift 实现 LRU Cache](https://www.jianshu.com/p/485385b65b54)
- [Swift 实现 LRU Cache](https://www.jianshu.com/p/485385b65b54)
- [Swift 实现 LRU Cache](https://www.jianshu.com/p/485385b65b54)
- [Swift get(key: key) // expected '{' to start getter definitioncache[key] = (value, Date(timeIntervalSinceNow: expiration)) // cannot assign through subscript: 'cache' is a 'let' constantcache[key] = nil // cannot assign through subscript: 'cache' is a 'let' constantget(key: key) // expected '{' to start getter definitionaccessOrder.remove(key) // no exact matches in call to instance method 'remove'accessOrder.remove(key) // no exact matches in call to instance method 'remove'let cache = ExpirableCache<String, String>() // missing argument for parameter 'expiration' in callThread.sleep(forTimeInterval: 1.1) // class method 'sleep' is unavailable from asynchronous contexts; Use Task.sleep(until:clock:) instead.; this is an error in Swift 6Thread.sleep(forTimeInterval: 0.9) // class method 'sleep' is unavailable from asynchronous contexts; Use Task.sleep(until:clock:) instead.; this is an error in Swift 6protocol ExpirableCacheProtocol {
associatedtype Key: Hashable
associatedtype Value
func put(value: Value, key: Key, expiration: TimeInterval)
func get(key: Key) -> Value?
}
class ExpirableCache<Key: Hashable, Value> {
private let cache: [Key: (value: Value, expiration: Date)]
private let expiration: TimeInterval
init(expiration: TimeInterval) {
self.expiration = expiration
self.cache = [:]
}
subscript(key: Key) -> Value? {
get(key: key)
}
func put(value: Value, key: Key, expiration: TimeInterval) {
cache[key] = (value, Date(timeIntervalSinceNow: expiration))
}
func get(key: Key) -> Value? {
guard let (value, expirationDate) = cache[key] else {
return nil
}
if expirationDate.timeIntervalSinceNow() < 0 {
cache.removeValue(forKey: key)
return nil
}
return value
}
}
class LRUCache {
private var cache: [Int: Int]
private var capacity: Int
private var time: Int
init(_ capacity: Int) {
self.capacity = capacity
self.cache = [:]
self.time = 0
}
func get(_ key: Int) -> Int {
guard let value = cache[key] else {
return -1
}
cache[key] = -1
cache[time] = key
time += 1
return value
}
func put(_ key: Int, _ value: Int) {
guard let oldValue = cache[key] else {
if cache.count == capacity {
cache[time] = key
cache.removeValue(forKey: cache[time])
time += 1
}
cache[key] = -1
time += 1
cache[time] = key
time += 1
return
}
cache[key] = -1
cache[time] = key
time += 1
}
}
class LRUCache {
private var capacity: Int
private var time: Int
private var cache: [Int: Node]
private var head: Node
private var tail: Node
init(_ capacity: Int) {
self.capacity = capacity
self.time = 0
self.cache = [:]
self.head = Node(-1, -1)
self.tail = Node(-1, -1)
head.next = tail
tail.prev = head
}
func get(_ key: Int) -> Int {
guard let node = cache[key] else {
return -1
}
removeNode(node)
addNode(node)
return node.value
}
func put(_ key: Int, _ value: Int) {
guard let node = cache[key] else {
if cache.count == capacity {
removeNode(tail.prev)
cache.removeValue(forKey: tail.prev.key)
}
cache[key] = Node(key, value)
addNode(cache[key]!)
return
}
removeNode(node)
node.value = value
addNode(node)
}
private func removeNode(_ node: Node) {
node.prev!.next = node.next
node.next!.prev = node.prev
}
private func addNode(_ node: Node) {
node.prev = tail.prev
node.next = tail
tail.prev!.next = node
tail.prev = node
}
}
class Node {
var key: Int
var value: Int
var prev: Node?
var next: Node?
init(_ key: Int, _ value: Int) {
self.key = key
self.value = value
}
}```swift
protocol ExpirableCacheProtocol {
associatedtype Key: Hashable
associatedtype Value
func put(value: Value, key: Key, expiration: TimeInterval)
func get(key: Key) -> Value?
}
// Caching mechanism with expiration eviction policy.
// Subscript methods used for convenient access.
class ExpirableCache<Key: Hashable, Value> {
private let cache: [Key: (value: Value, expiration: Date)]
private let expiration: TimeInterval
init(expiration: TimeInterval) {
self.expiration = expiration
self.cache = [:]
}
subscript(key: Key) -> Value? {
get(key: key)
}
func put(value: Value, key: Key, expiration: TimeInterval) {
cache[key] = (value, Date(timeIntervalSinceNow: expiration))
}
func get(key: Key) -> Value? {
guard let (value, expirationDate) = cache[key] else {
return nil
}
if expirationDate.timeIntervalSinceNow() < 0 {
cache.removeValue(forKey: key)
return nil
}
return value
}
}
```
### 解法二：LRU缓存
```swift
class LRUCache {
private var cache: [Int: Int]
private var capacity: Int
private var time: Int
init(_ capacity: Int) {
self.capacity = capacity
self.cache = [:]
self.time = 0
}
func get(_ key: Int) -> Int {
guard let value = cache[key] else {
return -1
}
cache[key] = -1
cache[time] = key
time += 1
return value
}
func put(_ key: Int, _ value: Int) {
guard let oldValue = cache[key] else {
if cache.count == capacity {
cache[time] = key
cache.removeValue(forKey: cache[time])
time += 1
}
cache[key] = -1
time += 1
cache[time] = key
time += 1
return
}
cache[key] = -1
cache[time] = key
time += 1
}
}
```
### 解法三：LRU缓存（双向链表）
```swift
class LRUCache {
private var capacity: Int
private var time: Int
private var cache: [Int: Node]
private var head: Node
private var tail: Node
init(_ capacity: Int) {
self.capacity = capacity
self.time = 0
self.cache = [:]
self.head = Node(-1, -1)
self.tail = Node(-1, -1)
head.next = tail
tail.prev = head
}
func get(_ key: Int) -> Int {
guard let node = cache[key] else {
return -1
}
removeNode(node)
addNode(node)
return node.value
}
func put(_ key: Int, _ value: Int) {
guard let node = cache[key] else {
if cache.count == capacity {
removeNode(tail.prev)
cache.removeValue(forKey: tail.prev.key)
}
cache[key] = Node(key, value)
addNode(cache[key]!)
return
}
removeNode(node)
node.value = value
addNode(node)
}
private func removeNode(_ node: Node) {
node.prev!.next = node.next
node.next!.prev = node.prev
}
private func addNode(_ node: Node) {
node.prev = tail.prev
node.next = tail
tail.prev!.next = node
tail.prev = node
}
}
class Node {
var key: Int
var value: Int
var prev: Node?
var next: Node?
init(_ key: Int, _ value: Int) {
self.key = key
self.value = value
}
}
```
### 解法四：LRU缓存（哈希表+双向链表get(key: key) // expected '{' to start getter definitioncache[key] = (value, Date(timeIntervalSinceNow: expiration)) // cannot assign through subscript: 'cache' is a 'let' constantif expirationDate.timeIntervalSinceNow() < 0 { // cannot call value of non-function type 'TimeInterval' (aka 'Double')cache.removeValue(forKey: key) // cannot use mutating member on immutable value: 'cache' is a 'let' constantcache.removeValue(forKey: cache[time]) // value of optional type 'Int?' must be unwrapped to a value of type 'Int'class LRUCache { // invalid redeclaration of 'LRUCache'removeNode(tail.prev) // value of optional type 'Node?' must be unwrapped to a value of type 'Node'cache.removeValue(forKey: tail.prev.key) // value of optional type 'Node?' must be unwrapped to refer to member 'key' of wrapped base type 'Node'let cache = ExpirableCache<String, String>() // missing argument for parameter 'expiration' in callThread.sleep(forTimeInterval: 1.1) // class method 'sleep' is unavailable from asynchronous contexts; Use Task.sleep(until:clock:) instead.; this is an error in Swift 6Thread.sleep(forTimeInterval: 0.9) // class method 'sleep' is unavailable from asynchronous contexts; Use Task.sleep(until:clock:) instead.; this is an error in Swift 6protocol ExpirableCacheProtocol {
associatedtype Key: Hashable
associatedtype Value
func put(value: Value, key: Key, expiration: TimeInterval)
func get(key: Key) -> Value?
}
class ExpirableCache<Key: Hashable, Value> {
private let cache: [Key: (value: Value, expiration: Date)]
private let expiration: TimeInterval
init(expiration: TimeInterval) {
self.expiration = expiration
self.cache = [:]
}
subscript(key: Key) -> Value? {
get(key: key)
}
func put(value: Value, key: Key, expiration: TimeInterval) {
cache[key] = (value, Date(timeIntervalSinceNow: expiration))
}
func get(key: Key) -> Value? {
guard let (value, expirationDate) = cache[key] else {
return nil
}
if expirationDate.timeIntervalSinceNow() < 0 {
cache.removeValue(forKey: key)
return nil
}
return value
}
}```swift
protocol ExpirableCacheProtocol {
associatedtype Key: Hashable
associatedtype Value
func put(value: Value, key: Key, expiration: TimeInterval)
func get(key: Key) -> Value?
}
// Caching mechanism with expiration eviction policy.
// Subscript methods used for convenient access.
class ExpirableCache<Key: Hashable, Value> {
private let cache: [Key: (value: Value, expiration: Date)]
private let expiration: TimeInterval
init(expiration: TimeInterval) {
self.expiration = expiration
self.cache = [:]
}
subscript(key: Key) -> Value? {
get(key: key)
}
func put(value: Value, key: Key, expiration: TimeInterval) {
cache[key] = (value, Date(timeIntervalSinceNow: expiration))
}
func get(key: Key) -> Value? {
guard let (value, expirationDate) = cache[key] else {
return nil
}
if expirationDate.timeIntervalSinceNow() < 0 {
cache.removeValue(forKey: key)
return nil
}
return value
}
}
```
### 解法二：LRU缓存机制
LRU缓存机制，即Least Recently Used，是一种缓存淘汰策略。
LRU缓存机制是一种缓存淘汰策略，当缓存空间不够时，将最近最少使用的数据删除。
在Swift中，`Dictionary`类型实现了`LRU`缓存机制，使用`removeValue(forKey:)`方法删除最久未使用的数据，使用`insert(newValue:, forKey:)`方法插入新的数据。
```swift
// Swift 自带的LRU缓存机制
let cache = [:]
cache.removeValue(forKey: key)
cache.insert(newValue: value, forKey: key)
```
### 解法三：LFU缓存机制
LFU缓存机制，即Least Frequently Used，是一种缓存淘汰策略。
LFU缓存机制是一种缓存淘汰策略，当缓存空间不够时，将访问次数最少的缓存删除。
在Swift中，`Dictionary`类型实现了`LFU`缓存机制，使用`removeValue(forKey:)`方法删除访问次数最少的缓存，使用`insert(newValue:, forKey:)`方法插入新的缓存。
```swift
// Swift 自带的LFU缓存机制
let cache = [:]
cache.removeValue(forKey: key)
cache.insert(newValue: value, forKey: key)
```
### 解法四：ARC缓存机制
ARC缓存机制，即Automatic Reference Counting，是一种缓存淘汰策略。
ARC缓存机制是一种缓存淘汰策略，当缓存空间不够时，将引用计数最小的缓存删除。
在Swift中，`Dictionary`类型实现了`ARC`缓存机制，使用`removeValue(forKey:)`方法删除引用计数最小的缓存，使用`insert(newValue:, forKey:)`方法插入新的缓存。
```swift
// Swift 自带的ARC缓存机制
let cache = [:]
cache.removeValue(forKey: key)
cache.insert(newValue: value, forKey: key)
```
### 解法五：FIFO缓存机制
FIFO缓存机制，即First-In-First-Out，是一种缓存淘汰策略。
FIFO缓存机制是一种缓存淘汰策略，当缓存空间不够时，将最先进入缓存的缓存删除。
在Swift中，`Dictionary`类型实现了`FIFO`缓存机制，使用`removeValue(forKey:)`方法删除最先进入缓存的缓存，使用`insert(newValue:, forKey:)`方法插入新的缓存。
```swift
// Swift 自带的FIFO缓存机制
let cache = [:]
cache.removeValue(forKey: key)
cache.insert(newValue: value, forKey: key)
```
### 解法六：LRU缓存机制的优化
LRU缓存机制的优化，即Least Recently Used with Double Linked List，是一种缓存淘汰策略。
LRU缓存机制的优化是一种缓存淘汰策略，当缓存空间不够时，将最近最少使用的数据删除。
在Swift中，`Dictionary`类型实现了`LRU`get(key: key) // expected '{' to start getter definitioncache[key] = (value, Date(timeIntervalSinceNow: expiration)) // cannot assign through subscript: 'cache' is a 'let' constantif expirationDate.timeIntervalSinceNow() < 0 { // cannot call value of non-function type 'TimeInterval' (aka 'Double')cache.removeValue(forKey: key) // cannot use mutating member on immutable value: 'cache' is a 'let' constantlet cache = ExpirableCache<String, String>() // missing argument for parameter 'expiration' in callThread.sleep(forTimeInterval: 1.1) // class method 'sleep' is unavailable from asynchronous contexts; Use Task.sleep(until:clock:) instead.; this is an error in Swift 6Thread.sleep(forTimeInterval: 0.9) // class method 'sleep' is unavailable from asynchronous contexts; Use Task.sleep(until:clock:) instead.; this is an error in Swift 6protocol ExpirableCacheProtocol {
associatedtype Key: Hashable
associatedtype Value
func put(value: Value, key: Key, expiration: TimeInterval)
func get(key: Key) -> Value?
}
class ExpirableCache<Key: Hashable, Value> {
private let cache: [Key: (value: Value, expiration: Date)]
private let expiration: TimeInterval
init(expiration: TimeInterval) {
self.expiration = expiration
self.cache = [:]
}
subscript(key: Key) -> Value? {
get(key: key)
}
func put(value: Value, key: Key, expiration: TimeInterval) {
cache[key] = (value, Date(timeIntervalSinceNow: expiration))
}
func get(key: Key) -> Value? {
guard let (value, expiration) = cache[key] else { return nil }
if expiration.timeIntervalSinceNow() < 0 {
cache.removeValue(forKey: key)
return nil
}
return value
}
}```swift
protocol ExpirableCacheProtocol {
associatedtype Key: Hashable
associatedtype Value
func put(value: Value, key: Key, expiration: TimeInterval)
func get(key: Key) -> Value?
}
// Caching mechanism with expiration eviction policy.
// Subscript methods used for convenient access.
class ExpirableCache<Key: Hashable, Value> {
private let cache: [Key: (value: Value, expiration: Date)]
private let expiration: TimeInterval
init(expiration: TimeInterval) {
self.expiration = expiration
self.cache = [:]
}
subscript(key: Key) -> Value? {
get(key: key)
}
func put(value: Value, key: Key, expiration: TimeInterval) {
cache[key] = (value, Date(timeIntervalSinceNow: expiration))
}
func get(key: Key) -> Value? {
guard let (value, expiration) = cache[key] else { return nil }
if expiration.timeIntervalSinceNow() < 0 {
cache.removeValue(forKey: key)
return nil
}
return value
}
}
```
### 解法二
```swift
class ExpirableCache<Key: Hashable, Value> {
private let cache: [Key: (value: Value, expiration: Date)]
private let expiration: TimeInterval
init(expiration: TimeInterval) {
self.expiration = expiration
self.cache = [:]
}
subscript(key: Key) -> Value? {
get(key: key)
}
func put(value: Value, key: Key, expiration: TimeInterval) {
cache[key] = (value, Date(timeIntervalSinceNow: expiration))
}
func get(key: Key) -> Value? {
guard let (value, expiration) = cache[key] else { return nil }
if expiration.timeIntervalSinceNow() < 0 {
cache.removeValue(forKey: key)
return nil
}
return value
}
}
```get(key: key) // expected '{' to start getter definitioncache[key] = (value, Date(timeIntervalSinceNow: expiration)) // cannot assign through subscript: 'cache' is a 'let' constantif expiration.timeIntervalSinceNow() < 0 { // cannot call value of non-function type 'TimeInterval' (aka 'Double')cache.removeValue(forKey: key) // cannot use mutating member on immutable value: 'cache' is a 'let' constantlet cache = ExpirableCache<String, String>() // missing argument for parameter 'expiration' in callThread.sleep(forTimeInterval: 1.1) // class method 'sleep' is unavailable from asynchronous contexts; Use Task.sleep(until:clock:) instead.; this is an error in Swift 6Thread.sleep(forTimeInterval: 0.9) // class method 'sleep' is unavailable from asynchronous contexts; Use Task.sleep(until:clock:) instead.; this is an error in Swift 6protocol ExpirableCacheProtocol {
associatedtype Key: Hashable
associatedtype Value
func put(value: Value, key: Key, expiration: TimeInterval)
func get(key: Key) -> Value?
}
class ExpirableCache<Key: Hashable, Value> {
private let cache: [Key: (Value, Date)]
private let expiration: TimeInterval
init(expiration: TimeInterval) {
self.expiration = expiration
self.cache = [:]
}
subscript(key: Key) -> Value? {
get(key: key)
}
func put(value: Value, key: Key, expiration: TimeInterval) {
cache[key] = (value, Date())
expiration = expiration
}
func get(key: Key) -> Value? {
guard let (value, date) = cache[key] else { return nil }
if date.timeIntervalSinceNow > expiration {
cache.removeValue(forKey: key)
return nil
}
return value
}
}```swift
protocol ExpirableCacheProtocol {
associatedtype Key: Hashable
associatedtype Value
func put(value: Value, key: Key, expiration: TimeInterval)
func get(key: Key) -> Value?
}
// Caching mechanism with expiration eviction policy.
// Subscript methods used for convenient access.
class ExpirableCache<Key: Hashable, Value> {
private let cache: [Key: (Value, Date)]
private let expiration: TimeInterval
init(expiration: TimeInterval) {
self.expiration = expiration
self.cache = [:]
}
subscript(key: Key) -> Value? {
get(key: key)
}
func put(value: Value, key: Key, expiration: TimeInterval) {
cache[key] = (value, Date())
expiration = expiration
}
func get(key: Key) -> Value? {
guard let (value, date) = cache[key] else { return nil }
if date.timeIntervalSinceNow > expiration {
cache.removeValue(forKey: key)
return nil
}
return value
}
}
```
### 解法二
```swift
class ExpirableCache<Key: Hashable, Value> {
private let cache: [Key: (Value, Date)]
private let expiration: TimeInterval
init(expiration: TimeInterval) {
self.expiration = expiration
self.cache = [:]
}
subscript(key: Key) -> Value? {
get(key: key)
}
func put(value: Value, key: Key, expiration: TimeInterval) {
cache[key] = (value, Date())
expiration = expiration
}
func get(key: Key) -> Value? {
guard let (value, date) = cache[key] else { return nil }
if date.timeIntervalSinceNow > expiration {
cache.removeValue(forKey: key)
return nil
}
return value
}
}
```
### 解法三
```swift
class ExpirableCache<Key: Hashable, Value> {
private let cache: [Key: (Value, Date)]
private let expiration: TimeInterval
init(expiration: TimeInterval) {
self.expiration = expiration
self.cache = [:]
}
subscript(key: Key) -> Value? {
get(key: key)
}
func put(value: Value, key: Key, expiration: TimeInterval) {
cache[key] = (value, Date())
expiration = expiration
}
func get(key: Key) -> Value? {
guard let (value, date) = cache[key] else { return nil }
if date.timeIntervalSinceNow > expiration {
cache.removeValue(forKey: key)
return nil
}
return value
}
}
```
### 解法四
```swift
class ExpirableCache<Key: Hashable, Value> {
private let cache: [Key: (Value, Date)]
private let expiration: TimeInterval
init(expiration: TimeInterval) {
self.expiration = expiration
self.cache = [:]
}
subscript(key: Key) -> Value? {
get(key: key)
}
func put(value: Value, key: Key, expiration: TimeInterval) {
cache[key] = (value, Date())
expiration = expiration
}
func get(key: Key) -> Value? {
guard let (value, date) = cache[key] else { return nil }
if date.timeIntervalSinceNow > expiration {
cache.removeValue(forKey: key)
return nil
}
return value
}
}
```
### 解法五
```swift
class ExpirableCache<Key: Hashable, Value> {
private let cache: [Key: (Value, Date)]
private let expiration: TimeInterval
init(expiration: TimeInterval) {
self.expiration = expiration
self.cache = [:]
}
subscript(key: Key) -> Value? {
get(key: key)
}
funcget(key: key) // expected '{' to start getter definitioncache[key] = (value, Date()) // cannot assign through subscript: 'cache' is a 'let' constantexpiration = expiration // cannot assign to value: 'expiration' is a 'let' constantcache.removeValue(forKey: key) // cannot use mutating member on immutable value: 'cache' is a 'let' constantlet cache = ExpirableCache<String, String>() // missing argument for parameter 'expiration' in callThread.sleep(forTimeInterval: 1.1) // class method 'sleep' is unavailable from asynchronous contexts; Use Task.sleep(until:clock:) instead.; this is an error in Swift 6Thread.sleep(forTimeInterval: 0.9) // class method 'sleep' is unavailable from asynchronous contexts; Use Task.sleep(until:clock:) instead.; this is an error in Swift 6protocol ExpirableCacheProtocol {
associatedtype Key: Hashable
associatedtype Value
func put(value: Value, key: Key, expiration: TimeInterval)
func get(key: Key) -> Value?
}
class ExpirableCache<Key: Hashable, Value> {
private var cache: [Key: (value: Value, expiration: Date)] = [:]
private let evictionPolicy: (Key, Date) -> Bool
init(evictionPolicy: @escaping (Key, Date) -> Bool) {
self.evictionPolicy = evictionPolicy
}
subscript(key: Key) -> Value? {
get(key: key)
}
func put(value: Value, key: Key, expiration: TimeInterval) {
let expirationDate = Date().addingTimeInterval(expiration)
cache[key] = (value, expirationDate)
}
func get(key: Key) -> Value? {
guard let (value, expirationDate) = cache[key] else {
return nil
}
if expirationDate < Date() {
cache.removeValue(forKey: key)
return nil
}
return value
}
}
class LRUCache<Key: Hashable, Value> {
private var cache: [Key: Value] = [:]
private var queue: [Key] = []
init() {}
subscript(key: Key) -> Value? {
get(key: key)
}
func put(value: Value, key: Key) {
guard let _ = cache[key] else {
queue.append(key)
}
cache[key] = value
queue.removeFirst()
queue.append(key)
}
func get(key: Key) -> Value? {
guard let _ = cache[key] else {
return nil
}
queue.removeFirst()
queue.append(key)
return cache[key]
}
}
class FIFOCache<Key: Hashable, Value> {
private var cache: [Key: Value] = [:]
private var queue: [Key] = []
init() {}
subscript(key: Key) -> Value? {
get(key: key)
}
func put(value: Value, key: Key) {
guard let _ = cache[key] else {
queue.append(key)
}
cache[key] = value
queue.removeFirst()
queue.append(key)
}
func get(key: Key) -> Value? {
guard let _ = cache[key] else {
return nil
}
queue.removeFirst()
queue.append(key)
return cache[key]
}
}```swift
protocol ExpirableCacheProtocol {
associatedtype Key: Hashable
associatedtype Value
func put(value: Value, key: Key, expiration: TimeInterval)
func get(key: Key) -> Value?
}
// Caching mechanism with expiration eviction policy.
// Subscript methods used for convenient access.
class ExpirableCache<Key: Hashable, Value> {
private var cache: [Key: (value: Value, expiration: Date)] = [:]
private let evictionPolicy: (Key, Date) -> Bool
init(evictionPolicy: @escaping (Key, Date) -> Bool) {
self.evictionPolicy = evictionPolicy
}
subscript(key: Key) -> Value? {
get(key: key)
}
func put(value: Value, key: Key, expiration: TimeInterval) {
let expirationDate = Date().addingTimeInterval(expiration)
cache[key] = (value, expirationDate)
}
func get(key: Key) -> Value? {
guard let (value, expirationDate) = cache[key] else {
return nil
}
if expirationDate < Date() {
cache.removeValue(forKey: key)
return nil
}
return value
}
}
// Caching mechanism with LRU eviction policy.
// Subscript methods used for convenient access.
class LRUCache<Key: Hashable, Value> {
private var cache: [Key: Value] = [:]
private var queue: [Key] = []
init() {}
subscript(key: Key) -> Value? {
get(key: key)
}
func put(value: Value, key: Key) {
guard let _ = cache[key] else {
queue.append(key)
}
cache[key] = value
queue.removeFirst()
queue.append(key)
}
func get(key: Key) -> Value? {
guard let _ = cache[key] else {
return nil
}
queue.removeFirst()
queue.append(key)
return cache[key]
}
}
// Caching mechanism with FIFO eviction policy.
// Subscript methods used for convenient access.
class FIFOCache<Key: Hashable, Value> {
private var cache: [Key: Value] = [:]
private var queue: [Key] = []
init() {}
subscript(key: Key) -> Value? {
get(key: key)
}
func put(value: Value, key: Key) {
guard let _ = cache[key] else {
queue.append(key)
}
cache[key] = value
queue.removeFirst()
queue.append(key)
}
func get(key: Key) -> Value? {
guard let _ = cache[key] else {
return nil
}
queue.removeFirst()
queue.append(key)
return cache[key]
}
}
```get(key: key) // expected '{' to start getter definitionget(key: key) // expected '{' to start getter definitionget(key: key) // expected '{' to start getter definitionlet cache = ExpirableCache<String, String>() // missing argument for parameter 'evictionPolicy' in callThread.sleep(forTimeInterval: 1.1) // class method 'sleep' is unavailable from asynchronous contexts; Use Task.sleep(until:clock:) instead.; this is an error in Swift 6Thread.sleep(forTimeInterval: 0.9) // class method 'sleep' is unavailable from asynchronous contexts; Use Task.sleep(until:clock:) instead.; this is an error in Swift 6protocol ExpirableCacheProtocol {
associatedtype Key: Hashable
associatedtype Value
func put(value: Value, key: Key, expiration: TimeInterval)
func get(key: Key) -> Value?
}
class ExpirableCache<Key: Hashable, Value> {
private let cache: [Key: (value: Value, expiration: Date)]
private let expiration: TimeInterval
init(expiration: TimeInterval) {
self.expiration = expiration
self.cache = [:]
}
subscript(key: Key) -> Value? {
get(key: key)
}
func put(value: Value, key: Key, expiration: TimeInterval) {
cache[key] = (value, Date(timeIntervalSinceNow: expiration))
}
func get(key: Key) -> Value? {
guard let (value, expiration) = cache[key] else {
return nil
}
if expiration < Date() {
cache.removeValue(forKey: key)
return nil
}
return value
}
}
class ExpirableCache {
private let cache: [Int: (value: Int, expiration: Date)]
private let expiration: TimeInterval
init(expiration: TimeInterval) {
self.expiration = expiration
self.cache = [:]
}
subscript(key: Int) -> Int? {
get(key: key)
}
func put(value: Int, key: Int, expiration: TimeInterval) {
cache[key] = (value, Date(timeIntervalSinceNow: expiration))
}
func get(key: Int) -> Int? {
guard let (value, expiration) = cache[key] else {
return nil
}
if expiration < Date() {
cache.removeValue(forKey: key)
return nil
}
return value
}
}```swift
protocol ExpirableCacheProtocol {
associatedtype Key: Hashable
associatedtype Value
func put(value: Value, key: Key, expiration: TimeInterval)
func get(key: Key) -> Value?
}
// Caching mechanism with expiration eviction policy.
// Subscript methods used for convenient access.
class ExpirableCache<Key: Hashable, Value> {
private let cache: [Key: (value: Value, expiration: Date)]
private let expiration: TimeInterval
init(expiration: TimeInterval) {
self.expiration = expiration
self.cache = [:]
}
subscript(key: Key) -> Value? {
get(key: key)
}
func put(value: Value, key: Key, expiration: TimeInterval) {
cache[key] = (value, Date(timeIntervalSinceNow: expiration))
}
func get(key: Key) -> Value? {
guard let (value, expiration) = cache[key] else {
return nil
}
if expiration < Date() {
cache.removeValue(forKey: key)
return nil
}
return value
}
}
```
### 解法二
```swift
class ExpirableCache {
private let cache: [Int: (value: Int, expiration: Date)]
private let expiration: TimeInterval
init(expiration: TimeInterval) {
self.expiration = expiration
self.cache = [:]
}
subscript(key: Int) -> Int? {
get(key: key)
}
func put(value: Int, key: Int, expiration: TimeInterval) {
cache[key] = (value, Date(timeIntervalSinceNow: expiration))
}
func get(key: Int) -> Int? {
guard let (value, expiration) = cache[key] else {
return nil
}
if expiration < Date() {
cache.removeValue(forKey: key)
return nil
}
return value
}
}
```
### 解法三
```swift
class ExpirableCache {
private let cache: [Int: (value: Int, expiration: Date)]
private let expiration: TimeInterval
init(expiration: TimeInterval) {
self.expiration = expiration
self.cache = [:]
}
subscript(key: Int) -> Int? {
get(key: key)
}
func put(value: Int, key: Int, expiration: TimeInterval) {
cache[key] = (value, Date(timeIntervalSinceNow: expiration))
}
func get(key: Int) -> Int? {
guard let (value, expiration) = cache[key] else {
return nil
}
if expiration < Date() {
cache.removeValue(forKey: key)
return nil
}
return value
}
}
```
### 解法四
```swift
class ExpirableCache {
private let cache: [Int: (value: Int, expiration: Date)]
private let expiration: TimeInterval
init(expiration: TimeInterval) {
self.expiration = expiration
self.cache = [:]
}
subscript(key: Int) -> Int? {
get(key: key)
}
func put(value: Int, key: Int, expiration: TimeInterval) {
cache[key] = (value, Date(timeIntervalSinceNow: expiration))
}
func get(key: Int) -> Int? {
guard let (value, expiration) = cache[key] else {
return nil
}
if expiration < Date() {
cache.removeValue(forKey: key)
return nil
}
return value
}
}
```
### 解法五
```swift
class ExpirableCache {
private let cache: [Int: (value: Int, expiration: Date)]
private let expiration: TimeInterval
init(expiration: TimeInterval) {
self.expiration = expiration
self.cache = [:]
}
subscript(key: Int) -> Int? {
get(key: key)
}
func put(value: Int, key:get(key: key) // expected '{' to start getter definitioncache[key] = (value, Date(timeIntervalSinceNow: expiration)) // cannot assign through subscript: 'cache' is a 'let' constantcache.removeValue(forKey: key) // cannot use mutating member on immutable value: 'cache' is a 'let' constantclass ExpirableCache { // invalid redeclaration of 'ExpirableCache'get(key: key) // expected '{' to start getter definitioncache[key] = (value, Date(timeIntervalSinceNow: expiration)) // cannot assign through subscript: 'cache' is a 'let' constantcache.removeValue(forKey: key) // cannot use mutating member on immutable value: 'cache' is a 'let' constantlet cache = ExpirableCache<String, String>() // missing argument for parameter 'expiration' in callThread.sleep(forTimeInterval: 1.1) // class method 'sleep' is unavailable from asynchronous contexts; Use Task.sleep(until:clock:) instead.; this is an error in Swift 6Thread.sleep(forTimeInterval: 0.9) // class method 'sleep' is unavailable from asynchronous contexts; Use Task.sleep(until:clock:) instead.; this is an error in Swift 6protocol ExpirableCacheProtocol {
associatedtype Key: Hashable
associatedtype Value
func put(value: Value, key: Key, expiration: TimeInterval)
func get(key: Key) -> Value?
}
class ExpirableCache<Key: Hashable, Value> {
private let cache: [Key: (value: Value, expiration: Date)]
private let expiration: TimeInterval
private let evictionPolicy: (Date) -> Bool
init(expiration: TimeInterval, evictionPolicy: @escaping (Date) -> Bool) {
self.expiration = expiration
self.evictionPolicy = evictionPolicy
self.cache = [:]
}
subscript(key: Key) -> Value? {
get(key: key)
}
func put(value: Value, key: Key, expiration: TimeInterval) {
let date = Date()
cache[key] = (value, date.addingTimeInterval(expiration))
}
func get(key: Key) -> Value? {
guard let (value, expiration) = cache[key] else { return nil }
if evictionPolicy(expiration) {
cache.removeValue(forKey: key)
}
return value
}
}
class LRUCache {
private let capacity: Int
private var cache: [Int: Int]
private var queue: [Int]
init(_ capacity: Int) {
self.capacity = capacity
self.cache = [:]
self.queue = []
}
func get(_ key: Int) -> Int {
guard let value = cache[key] else { return -1 }
queue.remove(at: queue.firstIndex(where: { $0 == key })!)
queue.append(key)
return value
}
func put(_ key: Int, _ value: Int) {
if cache[key] != nil {
queue.remove(at: queue.firstIndex(where: { $0 == key })!)
queue.append(key)
cache[key] = value
return
}
if cache.count == capacity {
let last = queue.removeLast()
cache.removeValue(forKey: last)
}
queue.append(key)
cache[key] = value
}
}
class LRUCache {
private let capacity: Int
private var cache: [Int: Node]
private var head: Node
private var tail: Node
init(_ capacity: Int) {
self.capacity = capacity
self.cache = [:]
head = Node(-1, -1)
tail = Node(-1, -1)
head.next = tail
tail.prev = head
}
func get(_ key: Int) -> Int {
guard let node = cache[key] else { return -1 }
removeNode(node)
addNode(node)
return node.value
}
func put(_ key: Int, _ value: Int) {
if cache[key] != nil {
guard let node = cache[key] else { return }
removeNode(node)
addNode(node)
node.value = value
return
}
if cache.count == capacity {
let last = tail.prev
removeNode(last)
cache.removeValue(forKey: last.key)
}
let node = Node(key, value)
addNode(node)
cache[key] = node
}
private func addNode(_ node: Node) {
node.next = head.next
node.prev = head
head.next?.prev = node
head.next = node
}
private func removeNode(_ node: Node) {
node.prev?.next = node.next
node.next?.prev = node.prev
}
}
class Node {
var key: Int
var value: Int
var prev: Node?
var next: Node?
init(_ key: Int, _ value: Int) {
self.key = key
self.value = value
}
}```swift
protocol ExpirableCacheProtocol {
associatedtype Key: Hashable
associatedtype Value
func put(value: Value, key: Key, expiration: TimeInterval)
func get(key: Key) -> Value?
}
// Caching mechanism with expiration eviction policy.
// Subscript methods used for convenient access.
class ExpirableCache<Key: Hashable, Value> {
private let cache: [Key: (value: Value, expiration: Date)]
private let expiration: TimeInterval
private let evictionPolicy: (Date) -> Bool
init(expiration: TimeInterval, evictionPolicy: @escaping (Date) -> Bool) {
self.expiration = expiration
self.evictionPolicy = evictionPolicy
self.cache = [:]
}
subscript(key: Key) -> Value? {
get(key: key)
}
func put(value: Value, key: Key, expiration: TimeInterval) {
let date = Date()
cache[key] = (value, date.addingTimeInterval(expiration))
}
func get(key: Key) -> Value? {
guard let (value, expiration) = cache[key] else { return nil }
if evictionPolicy(expiration) {
cache.removeValue(forKey: key)
}
return value
}
}
```
### 解法二：LRU
```swift
class LRUCache {
private let capacity: Int
private var cache: [Int: Int]
private var queue: [Int]
init(_ capacity: Int) {
self.capacity = capacity
self.cache = [:]
self.queue = []
}
func get(_ key: Int) -> Int {
guard let value = cache[key] else { return -1 }
queue.remove(at: queue.firstIndex(where: { $0 == key })!)
queue.append(key)
return value
}
func put(_ key: Int, _ value: Int) {
if cache[key] != nil {
queue.remove(at: queue.firstIndex(where: { $0 == key })!)
queue.append(key)
cache[key] = value
return
}
if cache.count == capacity {
let last = queue.removeLast()
cache.removeValue(forKey: last)
}
queue.append(key)
cache[key] = value
}
}
```
### 解法三：LRU + 双向链表
```swift
class LRUCache {
private let capacity: Int
private var cache: [Int: Node]
private var head: Node
private var tail: Node
init(_ capacity: Int) {
self.capacity = capacity
self.cache = [:]
head = Node(-1, -1)
tail = Node(-1, -1)
head.next = tail
tail.prev = head
}
func get(_ key: Int) -> Int {
guard let node = cache[key] else { return -1 }
removeNode(node)
addNode(node)
return node.value
}
func put(_ key: Int, _ value: Int) {
if cache[key] != nil {
guard let node = cache[key] else { return }
removeNode(node)
addNode(node)
node.value = value
return
}
if cache.count == capacity {
let last = tail.prev
removeNode(last)
cache.removeValue(forKey: last.key)
}
let node = Node(key, value)
addNode(node)
cache[key] = node
}
private func addNode(_ node: Node) {
node.next = head.next
node.prev = head
head.next?.prev = node
head.next = node
}
private func removeNode(_ node: Node) {
node.prev?.next = node.next
node.next?.prev = node.prev
}
}
class Node {
var key: Int
var value: Int
var prev: Node?
var next: Node?
init(_ key: Int, _ value: Int) {
self.key = key
self.value = value
}
}get(key: key) // expected '{' to start getter definitioncache[key] = (value, date.addingTimeInterval(expiration)) // cannot assign through subscript: 'cache' is a 'let' constantcache.removeValue(forKey: key) // cannot use mutating member on immutable value: 'cache' is a 'let' constantclass LRUCache { // invalid redeclaration of 'LRUCache'removeNode(last) // value of optional type 'Node?' must be unwrapped to a value of type 'Node'cache.removeValue(forKey: last.key) // value of optional type 'Node?' must be unwrapped to refer to member 'key' of wrapped base type 'Node'let cache = ExpirableCache<String, String>() // missing arguments for parameters 'expiration', 'evictionPolicy' in callThread.sleep(forTimeInterval: 1.1) // class method 'sleep' is unavailable from asynchronous contexts; Use Task.sleep(until:clock:) instead.; this is an error in Swift 6Thread.sleep(forTimeInterval: 0.9) // class method 'sleep' is unavailable from asynchronous contexts; Use Task.sleep(until:clock:) instead.; this is an error in Swift 6protocol ExpirableCacheProtocol {
associatedtype Key: Hashable
associatedtype Value
func put(value: Value, key: Key, expiration: TimeInterval)
func get(key: Key) -> Value?
}
class ExpirableCache<Key: Hashable, Value> {
private let cache: [Key: (value: Value, expiration: Date)]
private let expiration: TimeInterval
private let evictionPolicy: (Key, Value) -> Bool
init(expiration: TimeInterval, evictionPolicy: @escaping (Key, Value) -> Bool) {
self.expiration = expiration
self.evictionPolicy = evictionPolicy
self.cache = [:]
}
subscript(key: Key) -> Value? {
get(key: key)
}
func put(value: Value, key: Key, expiration: TimeInterval) {
let date = Date().addingTimeInterval(expiration)
cache[key] = (value, date)
}
func get(key: Key) -> Value? {
guard let (value, expirationDate) = cache[key] else { return nil }
guard expirationDate > Date() else {
cache.removeValue(forKey: key)
return nil
}
return value
}
}
class ExpirableCacheTests: XCTestCase {
func test_put_and_get_with_expiration() {
let cache = ExpirableCache<Int, Int>(expiration: 1, evictionPolicy: { $0 == 1 })
cache.put(value: 1, key: 1, expiration: 1)
cache.put(value: 2, key: 2, expiration: 2)
cache.put(value: 3, key: 3, expiration: 3)
XCTAssertEqual(cache[1], 1)
XCTAssertEqual(cache[2], 2)
XCTAssertEqual(cache[3], 3)
XCTAssertNil(cache[1])
XCTAssertEqual(cache[2], 2)
XCTAssertEqual(cache[3], 3)
XCTAssertNil(cache[2])
XCTAssertNil(cache[3])
}
func test_put_and_get_with_expiration_eviction_policy() {
let cache = ExpirableCache<Int, Int>(expiration: 1, evictionPolicy: { $0 == 1 })
cache.put(value: 1, key: 1, expiration: 1)
cache.put(value: 2, key: 2, expiration: 2)
cache.put(value: 3, key: 3, expiration: 3)
XCTAssertEqual(cache[1], 1)
XCTAssertEqual(cache[2], 2)
XCTAssertEqual(cache[3], 3)
cache.put(value: 4, key: 4, expiration: 4)
cache.put(value: 5, key: 5, expiration: 5)
XCTAssertNil(cache[1])
XCTAssertEqual(cache[2], 2)
XCTAssertEqual(cache[3], 3)
XCTAssertNil(cache[2])
XCTAssertNil(cache[3])
XCTAssertEqual(cache[4], 4)
XCTAssertEqual(cache[5], 5)
}
}
func generic<T>(_ value: T) -> T {
return value
}```swift
protocol ExpirableCacheProtocol {
associatedtype Key: Hashable
associatedtype Value
func put(value: Value, key: Key, expiration: TimeInterval)
func get(key: Key) -> Value?
}
// Caching mechanism with expiration eviction policy.
// Subscript methods used for convenient access.
class ExpirableCache<Key: Hashable, Value> {
private let cache: [Key: (value: Value, expiration: Date)]
private let expiration: TimeInterval
private let evictionPolicy: (Key, Value) -> Bool
init(expiration: TimeInterval, evictionPolicy: @escaping (Key, Value) -> Bool) {
self.expiration = expiration
self.evictionPolicy = evictionPolicy
self.cache = [:]
}
subscript(key: Key) -> Value? {
get(key: key)
}
func put(value: Value, key: Key, expiration: TimeInterval) {
let date = Date().addingTimeInterval(expiration)
cache[key] = (value, date)
}
func get(key: Key) -> Value? {
guard let (value, expirationDate) = cache[key] else { return nil }
guard expirationDate > Date() else {
cache.removeValue(forKey: key)
return nil
}
return value
}
}
// MARK: - Tests
class ExpirableCacheTests: XCTestCase {
func test_put_and_get_with_expiration() {
let cache = ExpirableCache<Int, Int>(expiration: 1, evictionPolicy: { $0 == 1 })
cache.put(value: 1, key: 1, expiration: 1)
cache.put(value: 2, key: 2, expiration: 2)
cache.put(value: 3, key: 3, expiration: 3)
XCTAssertEqual(cache[1], 1)
XCTAssertEqual(cache[2], 2)
XCTAssertEqual(cache[3], 3)
XCTAssertNil(cache[1])
XCTAssertEqual(cache[2], 2)
XCTAssertEqual(cache[3], 3)
XCTAssertNil(cache[2])
XCTAssertNil(cache[3])
}
func test_put_and_get_with_expiration_eviction_policy() {
let cache = ExpirableCache<Int, Int>(expiration: 1, evictionPolicy: { $0 == 1 })
cache.put(value: 1, key: 1, expiration: 1)
cache.put(value: 2, key: 2, expiration: 2)
cache.put(value: 3, key: 3, expiration: 3)
XCTAssertEqual(cache[1], 1)
XCTAssertEqual(cache[2], 2)
XCTAssertEqual(cache[3], 3)
cache.put(value: 4, key: 4, expiration: 4)
cache.put(value: 5, key: 5, expiration: 5)
XCTAssertNil(cache[1])
XCTAssertEqual(cache[2], 2)
XCTAssertEqual(cache[3], 3)
XCTAssertNil(cache[2])
XCTAssertNil(cache[3])
XCTAssertEqual(cache[4], 4)
XCTAssertEqual(cache[5], 5)
}
}
```
### 3. 泛型函数
泛型函数的定义：
```swift
func generic<T>(_ value: T) -> T {
return value
}
```
泛型函数的调用：
```swift
let result = generic(1)
```
泛型函数的实现：
```swift
func generic<T>(_ value: T) -> T {
return value
}
```
泛型函数的类型推断：
```swift
let result: Int = generic(1)
```
泛型函数的类型推断：
```swift
let result: Int = generic(1)
```
泛型函数的类型推断：
```swift
let result: Int = generic(1)
```
泛型函数的类型推断：get(key: key) // expected '{' to start getter definitioncache[key] = (value, date) // cannot assign through subscript: 'cache' is a 'let' constantcache.removeValue(forKey: key) // cannot use mutating member on immutable value: 'cache' is a 'let' constantlet cache = ExpirableCache<Int, Int>(expiration: 1, evictionPolicy: { $0 == 1 }) // contextual closure type '(Int, Int) -> Bool' expects 2 arguments, but 1 was used in closure bodylet cache = ExpirableCache<Int, Int>(expiration: 1, evictionPolicy: { $0 == 1 }) // contextual closure type '(Int, Int) -> Bool' expects 2 arguments, but 1 was used in closure bodylet cache = ExpirableCache<String, String>() // missing arguments for parameters 'expiration', 'evictionPolicy' in callThread.sleep(forTimeInterval: 1.1) // class method 'sleep' is unavailable from asynchronous contexts; Use Task.sleep(until:clock:) instead.; this is an error in Swift 6Thread.sleep(forTimeInterval: 0.9) // class method 'sleep' is unavailable from asynchronous contexts; Use Task.sleep(until:clock:) instead.; this is an error in Swift 6protocol EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data
func decrypt(_ data: Data, _ key: String) -> String
}
class Encryptor: EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data {
let data = string.data(using: .utf8)
let keyData = key.data(using: .utf8)
let encryptedData = data.xor(keyData)
return encryptedData
}
func decrypt(_ data: Data, _ key: String) -> String {
let keyData = key.data(using: .utf8)
let decryptedData = data.xor(keyData)
return String(decryptedData.utf8)
}
}
class Encryptor: EncryptorProtocol {
// 加密解密算法
private let algorithm: Algorithm
// 加密解密密钥
private let key: String
// 初始化加密解密器
init(algorithm: Algorithm, key: String) {
self.algorithm = algorithm
self.key = key
}
// 加密
func encrypt(_ string: String, _ key: String) -> Data {
let data = string.data(using: .utf8)
let keyData = key.data(using: .utf8)
let encryptedData = data.encrypted(using: algorithm, password: keyData)
return encryptedData
}
// 解密
func decrypt(_ data: Data, _ key: String) -> String {
let keyData = key.data(using: .utf8)
let decryptedData = data.decrypted(using: algorithm, password: keyData)
return String(decryptedData.utf8)
}
}
class EncryptorFactory {
// 加密解密器
private var encryptor: EncryptorProtocol
// 加密解密算法
private var algorithm: Algorithm
// 加密解密密钥
private var key: String
// 初始化加密解密器工厂
init(encryptor: EncryptorProtocol) {
self.encryptor = encryptor
}
// 获取加密解密器
func getEncryptor() -> EncryptorProtocol {
return encryptor
}
// 获取加密解密算法
func getAlgorithm() -> Algorithm {
return algorithm
}
// 获取加密解密密钥
func getKey() -> String {
return key
}
}
class EncryptorFactoryFactory {
// 加密解密器工厂
private var factory: EncryptorFactoryProtocol
// 加密解密算法
private var algorithm: Algorithm
// 加密解密密钥
private var key: String
// 初始化加密解密器工厂工厂
init(factory: EncryptorFactoryProtocol) {
self.factory = factory
}
// 获取加密解密器工厂
func getFactory() -> EncryptorFactoryProtocol {
return factory
}
// 获取加密解密算法
func getAlgorithm() -> Algorithm {
return algorithm
}
// 获取加密解密密钥
func getKey() -> String {
return key
}
}```swift
protocol EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data
func decrypt(_ data: Data, _ key: String) -> String
}
// Simple XOR encryptor and decryptor that converts plain text into encrypted text by applying the binary 'Exclusive OR' operator implemented according to the protocol.
class Encryptor: EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data {
let data = string.data(using: .utf8)
let keyData = key.data(using: .utf8)
let encryptedData = data.xor(keyData)
return encryptedData
}
func decrypt(_ data: Data, _ key: String) -> String {
let keyData = key.data(using: .utf8)
let decryptedData = data.xor(keyData)
return String(decryptedData.utf8)
}
}
```
### 2.2 实现一个加密解密器
```swift
// 加密解密器
class Encryptor: EncryptorProtocol {
// 加密解密算法
private let algorithm: Algorithm
// 加密解密密钥
private let key: String
// 初始化加密解密器
init(algorithm: Algorithm, key: String) {
self.algorithm = algorithm
self.key = key
}
// 加密
func encrypt(_ string: String, _ key: String) -> Data {
let data = string.data(using: .utf8)
let keyData = key.data(using: .utf8)
let encryptedData = data.encrypted(using: algorithm, password: keyData)
return encryptedData
}
// 解密
func decrypt(_ data: Data, _ key: String) -> String {
let keyData = key.data(using: .utf8)
let decryptedData = data.decrypted(using: algorithm, password: keyData)
return String(decryptedData.utf8)
}
}
```
### 2.3 实现一个加密解密器工厂
```swift
// 加密解密器工厂
class EncryptorFactory {
// 加密解密器
private var encryptor: EncryptorProtocol
// 加密解密算法
private var algorithm: Algorithm
// 加密解密密钥
private var key: String
// 初始化加密解密器工厂
init(encryptor: EncryptorProtocol) {
self.encryptor = encryptor
}
// 获取加密解密器
func getEncryptor() -> EncryptorProtocol {
return encryptor
}
// 获取加密解密算法
func getAlgorithm() -> Algorithm {
return algorithm
}
// 获取加密解密密钥
func getKey() -> String {
return key
}
}
```
### 2.4 实现一个加密解密器工厂工厂
```swift
// 加密解密器工厂工厂
class EncryptorFactoryFactory {
// 加密解密器工厂
private var factory: EncryptorFactoryProtocol
// 加密解密算法
private var algorithm: Algorithm
// 加密解密密钥
private var key: String
// 初始化加密解密器工厂工厂
init(factory: EncryptorFactoryProtocol) {
self.factory = factory
}
// 获取加密解密器工厂
func getFactory() -> EncryptorFactoryProtocol {
return factory
}
// 获取加密解密算法
func getAlgorithm() -> Algorithm {
return algorithm
}
// 获取加密解密密钥
func getKey() -> String {
return key
}
}
```
### 2.5 实现一个加密解密器工厂工厂工厂
```swift
// 加密解密器工厂工厂工厂
class EncryptorFactoryFactoryFactory {
// 加密解密器工厂工厂
private var factoryFactory: EncryptorFactoryFactoryProtocol
// 加密解密算法
private var algorithm: Algorithm
// 加密解密密钥
private var key: String
// 初始化加密解密器工厂工厂工厂
init(factoryFactory: EncryptorFactoryFactoryProtocol) {
self.factoryFactory = factoryFactory
}
// 获取加密解密器工厂工厂
func getlet encryptedData = data.xor(keyData) // value of type 'Data?' has no member 'xor'let decryptedData = data.xor(keyData) // value of type 'Data' has no member 'xor'class Encryptor: EncryptorProtocol { // invalid redeclaration of 'Encryptor'private let algorithm: Algorithm // cannot find type 'Algorithm' in scopeinit(algorithm: Algorithm, key: String) { // cannot find type 'Algorithm' in scopelet encryptedData = data.encrypted(using: algorithm, password: keyData) // value of type 'Data?' has no member 'encrypted'let decryptedData = data.decrypted(using: algorithm, password: keyData) // value of type 'Data' has no member 'decrypted'private var algorithm: Algorithm // cannot find type 'Algorithm' in scopefunc getAlgorithm() -> Algorithm { // cannot find type 'Algorithm' in scopeprivate var factory: EncryptorFactoryProtocol // cannot find type 'EncryptorFactoryProtocol' in scopeprivate var algorithm: Algorithm // cannot find type 'Algorithm' in scopeinit(factory: EncryptorFactoryProtocol) { // cannot find type 'EncryptorFactoryProtocol' in scopefunc getFactory() -> EncryptorFactoryProtocol { // cannot find type 'EncryptorFactoryProtocol' in scopefunc getAlgorithm() -> Algorithm { // cannot find type 'Algorithm' in scopeprotocol EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data
func decrypt(_ data: Data, _ key: String) -> String
}
class Encryptor: EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data {
let data = string.data(using: .utf8)
let keyData = key.data(using: .utf8)
var result = Data(count: data.count)
data.enumerated().forEach { (offset, byte) in
result[offset] = byte ^ keyData![offset % keyData.count]
}
return result
}
func decrypt(_ data: Data, _ key: String) -> String {
let keyData = key.data(using: .utf8)
var result = ""
data.enumerated().forEach { (offset, byte) in
result += String(byte ^ keyData![offset % keyData.count])
}
return result
}
}```swift
protocol EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data
func decrypt(_ data: Data, _ key: String) -> String
}
// Simple XOR encryptor and decryptor that converts plain text into encrypted text by applying the binary 'Exclusive OR' operator implemented according to the protocol.
class Encryptor: EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data {
let data = string.data(using: .utf8)
let keyData = key.data(using: .utf8)
var result = Data(count: data.count)
data.enumerated().forEach { (offset, byte) in
result[offset] = byte ^ keyData![offset % keyData.count]
}
return result
}
func decrypt(_ data: Data, _ key: String) -> String {
let keyData = key.data(using: .utf8)
var result = ""
data.enumerated().forEach { (offset, byte) in
result += String(byte ^ keyData![offset % keyData.count])
}
return result
}
}
```var result = Data(count: data.count) // value of optional type 'Data?' must be unwrapped to refer to member 'count' of wrapped base type 'Data'data.enumerated().forEach { (offset, byte) in // value of optional type 'Data?' must be unwrapped to refer to member 'enumerated' of wrapped base type 'Data'result[offset] = byte ^ keyData![offset % keyData.count] // value of optional type 'Data?' must be unwrapped to refer to member 'count' of wrapped base type 'Data'result += String(byte ^ keyData![offset % keyData.count]) // value of optional type 'Data?' must be unwrapped to refer to member 'count' of wrapped base type 'Data'protocol EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data
func decrypt(_ data: Data, _ key: String) -> String
}
class Encryptor: EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data {
let data = string.utf8.map { key.utf8[Int($0 ^ key.utf8.first!)] }
return Data(bytes: data)
}
func decrypt(_ data: Data, _ key: String) -> String {
let bytes = data.bytes
let keyBytes = key.utf8
var result = [UInt8]()
for i in 0..<data.count {
result.append(bytes[i] ^ keyBytes[Int(bytes[i])])
}
return String(bytes: result, encoding: .utf8)
}
}```swift
protocol EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data
func decrypt(_ data: Data, _ key: String) -> String
}
// Simple XOR encryptor and decryptor that converts plain text into encrypted text by applying the binary 'Exclusive OR' operator implemented according to the protocol.
class Encryptor: EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data {
let data = string.utf8.map { key.utf8[Int($0 ^ key.utf8.first!)] }
return Data(bytes: data)
}
func decrypt(_ data: Data, _ key: String) -> String {
let bytes = data.bytes
let keyBytes = key.utf8
var result = [UInt8]()
for i in 0..<data.count {
result.append(bytes[i] ^ keyBytes[Int(bytes[i])])
}
return String(bytes: result, encoding: .utf8)
}
}
// Simple XOR encryptor and decryptor that converts plain text into encrypted text by applying the binary 'Exclusive OR' operator implemented according to the protocol.
class Encryptor: EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data {
let data = string.utf8.map { key.utf8[Int($0 ^ key.utf8.first!)] }
return Data(bytes: data)
}
func decrypt(_ data: Data, _ key: String) -> String {
let bytes = data.bytes
let keyBytes = key.utf8
var result = [UInt8]()
for i in 0..<data.count {
result.append(bytes[i] ^ keyBytes[Int(bytes[i])])
}
return String(bytes: result, encoding: .utf8)
}
}
```let data = string.utf8.map { key.utf8[Int($0 ^ key.utf8.first!)] } // no exact matches in call to subscriptlet bytes = data.bytes // value of type 'Data' has no member 'bytes'return String(bytes: result, encoding: .utf8) // value of optional type 'String?' must be unwrapped to a value of type 'String'protocol EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data
func decrypt(_ data: Data, _ key: String) -> String
}
class Encryptor: EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data {
let data = string.utf8EncodedData
var result = Data(count: data.count)
for i in 0..<data.count {
result[i] = data[i] ^ Int(key.utf8.first!.hexadecimalValue)
}
return result
}
func decrypt(_ data: Data, _ key: String) -> String {
let result = String(data: data, encoding: .utf8)
let keyInt = Int(key.utf8.first!.hexadecimalValue)
let dataInt = Int(result.utf8.first!.hexadecimalValue)
let resultInt = dataInt ^ keyInt
return String(unicodeScalars: Array(result.utf8) as UnicodeScalarArray, count: result.count)
}
}```swift
protocol EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data
func decrypt(_ data: Data, _ key: String) -> String
}
// Simple XOR encryptor and decryptor that converts plain text into encrypted text by applying the binary 'Exclusive OR' operator implemented according to the protocol.
class Encryptor: EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data {
let data = string.utf8EncodedData
var result = Data(count: data.count)
for i in 0..<data.count {
result[i] = data[i] ^ Int(key.utf8.first!.hexadecimalValue)
}
return result
}
func decrypt(_ data: Data, _ key: String) -> String {
let result = String(data: data, encoding: .utf8)
let keyInt = Int(key.utf8.first!.hexadecimalValue)
let dataInt = Int(result.utf8.first!.hexadecimalValue)
let resultInt = dataInt ^ keyInt
return String(unicodeScalars: Array(result.utf8) as UnicodeScalarArray, count: result.count)
}
}
```let data = string.utf8EncodedData // value of type 'String' has no member 'utf8EncodedData'let keyInt = Int(key.utf8.first!.hexadecimalValue) // value of type 'String.UTF8View.Element' (aka 'UInt8') has no member 'hexadecimalValue'let dataInt = Int(result.utf8.first!.hexadecimalValue) // value of type 'String.UTF8View.Element' (aka 'UInt8') has no member 'hexadecimalValue'let dataInt = Int(result.utf8.first!.hexadecimalValue) // value of optional type 'String?' must be unwrapped to refer to member 'utf8' of wrapped base type 'String'return String(unicodeScalars: Array(result.utf8) as UnicodeScalarArray, count: result.count) // value of optional type 'String?' must be unwrapped to refer to member 'count' of wrapped base type 'String'return String(unicodeScalars: Array(result.utf8) as UnicodeScalarArray, count: result.count) // no exact matches in call to initializerreturn String(unicodeScalars: Array(result.utf8) as UnicodeScalarArray, count: result.count) // no exact matches in call to initializerreturn String(unicodeScalars: Array(result.utf8) as UnicodeScalarArray, count: result.count) // cannot find type 'UnicodeScalarArray' in scopereturn String(unicodeScalars: Array(result.utf8) as UnicodeScalarArray, count: result.count) // value of optional type 'String?' must be unwrapped to refer to member 'utf8' of wrapped base type 'String'protocol EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data
func decrypt(_ data: Data, _ key: String) -> String
}
class Encryptor: EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data {
let data = string.utf8.map { $0 ^ UInt8(key.utf8[Int(random(in: 0..<key.count))]) }
return Data(data: data)
}
func decrypt(_ data: Data, _ key: String) -> String {
let bytes = data.map { $0 ^ UInt8(key.utf8[Int(random(in: 0..<key.count))]) }
return String(bytes: bytes, encoding: .utf8)
}
}
class Encryptor: EncryptorProtocol {
let key: String
init(_ key: String) {
self.key = key
}
func encrypt(_ string: String, _ key: String) -> Data {
let data = string.utf8.map { $0 ^ UInt8(key.utf8[Int(random(in: 0..<key.count))]) }
return Data(data: data)
}
func decrypt(_ data: Data, _ key: String) -> String {
let bytes = data.map { $0 ^ UInt8(key.utf8[Int(random(in: 0..<key.count))]) }
return String(bytes: bytes, encoding: .utf8)
}
}```swift
protocol EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data
func decrypt(_ data: Data, _ key: String) -> String
}
// Simple XOR encryptor and decryptor that converts plain text into encrypted text by applying the binary 'Exclusive OR' operator implemented according to the protocol.
class Encryptor: EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data {
let data = string.utf8.map { $0 ^ UInt8(key.utf8[Int(random(in: 0..<key.count))]) }
return Data(data: data)
}
func decrypt(_ data: Data, _ key: String) -> String {
let bytes = data.map { $0 ^ UInt8(key.utf8[Int(random(in: 0..<key.count))]) }
return String(bytes: bytes, encoding: .utf8)
}
}
// Simple XOR encryptor and decryptor that converts plain text into encrypted text by applying the binary 'Exclusive OR' operator implemented according to the protocol.
class Encryptor: EncryptorProtocol {
let key: String
init(_ key: String) {
self.key = key
}
func encrypt(_ string: String, _ key: String) -> Data {
let data = string.utf8.map { $0 ^ UInt8(key.utf8[Int(random(in: 0..<key.count))]) }
return Data(data: data)
}
func decrypt(_ data: Data, _ key: String) -> String {
let bytes = data.map { $0 ^ UInt8(key.utf8[Int(random(in: 0..<key.count))]) }
return String(bytes: bytes, encoding: .utf8)
}
}
```let data = string.utf8.map { $0 ^ UInt8(key.utf8[Int(random(in: 0..<key.count))]) } // cannot convert value of type 'Int' to expected argument type 'String.UTF8View.Index' (aka 'String.Index')let data = string.utf8.map { $0 ^ UInt8(key.utf8[Int(random(in: 0..<key.count))]) } // argument passed to call that takes no argumentsreturn Data(data: data) // no exact matches in call to initializerlet bytes = data.map { $0 ^ UInt8(key.utf8[Int(random(in: 0..<key.count))]) } // argument passed to call that takes no argumentslet bytes = data.map { $0 ^ UInt8(key.utf8[Int(random(in: 0..<key.count))]) } // cannot convert value of type 'Int' to expected argument type 'String.UTF8View.Index' (aka 'String.Index')return String(bytes: bytes, encoding: .utf8) // value of optional type 'String?' must be unwrapped to a value of type 'String'class Encryptor: EncryptorProtocol { // invalid redeclaration of 'Encryptor'let data = string.utf8.map { $0 ^ UInt8(key.utf8[Int(random(in: 0..<key.count))]) } // argument passed to call that takes no argumentslet data = string.utf8.map { $0 ^ UInt8(key.utf8[Int(random(in: 0..<key.count))]) } // cannot convert value of type 'Int' to expected argument type 'String.UTF8View.Index' (aka 'String.Index')return Data(data: data) // no exact matches in call to initializerlet bytes = data.map { $0 ^ UInt8(key.utf8[Int(random(in: 0..<key.count))]) } // argument passed to call that takes no argumentslet bytes = data.map { $0 ^ UInt8(key.utf8[Int(random(in: 0..<key.count))]) } // cannot convert value of type 'Int' to expected argument type 'String.UTF8View.Index' (aka 'String.Index')return String(bytes: bytes, encoding: .utf8) // value of optional type 'String?' must be unwrapped to a value of type 'String'protocol EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data
func decrypt(_ data: Data, _ key: String) -> String
}
class Encryptor: EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data {
let data = string.utf8.map { $0 ^ Int(key.utf8[key.utf8.index(key.utf8.startIndex, offsetBy: $0)]) }
return Data(data: data)
}
func decrypt(_ data: Data, _ key: String) -> String {
let string = data.map { $0 ^ Int(key.utf8[key.utf8.startIndex.advanced(by: $0)]) }
return String(string: string, encoding: .utf8)
}
}```swift
protocol EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data
func decrypt(_ data: Data, _ key: String) -> String
}
// Simple XOR encryptor and decryptor that converts plain text into encrypted text by applying the binary 'Exclusive OR' operator implemented according to the protocol.
class Encryptor: EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data {
let data = string.utf8.map { $0 ^ Int(key.utf8[key.utf8.index(key.utf8.startIndex, offsetBy: $0)]) }
return Data(data: data)
}
func decrypt(_ data: Data, _ key: String) -> String {
let string = data.map { $0 ^ Int(key.utf8[key.utf8.startIndex.advanced(by: $0)]) }
return String(string: string, encoding: .utf8)
}
}
// Simple XOR encryptor and decryptor that converts plain text into encrypted text by applying the binary 'Exclusive OR' operator implemented according to the protocol.
class Encryptor: EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data {
let data = string.utf8.map { $0 ^ Int(key.utf8[key.utf8.index(key.utf8.startIndex, offsetBy: $0)]) }
return Data(data: data)
}
func decrypt(_ data: Data, _ key: String) -> String {
let string = data.map { $0 ^ Int(key.utf8[key.utf8.startIndex.advanced(by: $0)]) }
return String(string: string, encoding: .utf8)
}
}
```let data = string.utf8.map { $0 ^ Int(key.utf8[key.utf8.index(key.utf8.startIndex, offsetBy: $0)]) } // binary operator '^' cannot be applied to operands of type 'String.UTF8View.Element' (aka 'UInt8') and 'Int'return Data(data: data) // no exact matches in call to initializerlet string = data.map { $0 ^ Int(key.utf8[key.utf8.startIndex.advanced(by: $0)]) } // binary operator '^' cannot be applied to operands of type 'Data.Element' (aka 'UInt8') and 'Int'let string = data.map { $0 ^ Int(key.utf8[key.utf8.startIndex.advanced(by: $0)]) } // value of type 'String.UTF8View.Index' (aka 'String.Index') has no member 'advanced'return String(string: string, encoding: .utf8) // no exact matches in call to initializerprotocol EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data
func decrypt(_ data: Data, _ key: String) -> String
}
class Encryptor: EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data {
let data = string.data(using: .utf8)
let keyData = key.data(using: .utf8)
let result = data.map { $0 ^ Int(keyData![keyData.index(keyData.startIndex, offsetBy: $0)]) }
return Data(result)
}
func decrypt(_ data: Data, _ key: String) -> String {
let keyData = key.data(using: .utf8)
let result = data.map { Int($0) ^ Int(keyData![keyData.index(keyData.startIndex, offsetBy: $0)]) }
return String(result)
}
}```swift
protocol EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data
func decrypt(_ data: Data, _ key: String) -> String
}
// Simple XOR encryptor and decryptor that converts plain text into encrypted text by applying the binary 'Exclusive OR' operator implemented according to the protocol.
class Encryptor: EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data {
let data = string.data(using: .utf8)
let keyData = key.data(using: .utf8)
let result = data.map { $0 ^ Int(keyData![keyData.index(keyData.startIndex, offsetBy: $0)]) }
return Data(result)
}
func decrypt(_ data: Data, _ key: String) -> String {
let keyData = key.data(using: .utf8)
let result = data.map { Int($0) ^ Int(keyData![keyData.index(keyData.startIndex, offsetBy: $0)]) }
return String(result)
}
}
```let result = data.map { $0 ^ Int(keyData![keyData.index(keyData.startIndex, offsetBy: $0)]) } // value of optional type 'Data?' must be unwrapped to refer to member 'index' of wrapped base type 'Data'let result = data.map { $0 ^ Int(keyData![keyData.index(keyData.startIndex, offsetBy: $0)]) } // cannot convert value of type 'Data' to expected argument type 'Int'let result = data.map { $0 ^ Int(keyData![keyData.index(keyData.startIndex, offsetBy: $0)]) } // value of optional type 'Data?' must be unwrapped to refer to member 'startIndex' of wrapped base type 'Data'let result = data.map { $0 ^ Int(keyData![keyData.index(keyData.startIndex, offsetBy: $0)]) } // instance method 'index(_:offsetBy:)' requires that 'Data' conform to 'BinaryInteger'let result = data.map { Int($0) ^ Int(keyData![keyData.index(keyData.startIndex, offsetBy: $0)]) } // value of optional type 'Data?' must be unwrapped to refer to member 'startIndex' of wrapped base type 'Data'let result = data.map { Int($0) ^ Int(keyData![keyData.index(keyData.startIndex, offsetBy: $0)]) } // value of optional type 'Data?' must be unwrapped to refer to member 'index' of wrapped base type 'Data'protocol EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data
func decrypt(_ data: Data, _ key: String) -> String
}
class Encryptor: EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data {
let data = string.utf8.map { $0 ^ UInt8(key.utf8[Int(random() * key.count)]) }
return Data(bytes: data, count: string.count)
}
func decrypt(_ data: Data, _ key: String) -> String {
let bytes = data.bytes
let data = bytes.map { $0 ^ UInt8(key.utf8[Int(random() * key.count)]) }
return String(bytes: data, count: data.count)
}
}
class Encryptor: EncryptorProtocol {
let key: String
init(_ key: String) {
self.key = key
}
func encrypt(_ string: String, _ key: String) -> Data {
let data = string.utf8.map { $0 ^ UInt8(key.utf8[Int(random() * key.count)]) }
return Data(bytes: data, count: string.count)
}
func decrypt(_ data: Data, _ key: String) -> String {
let bytes = data.bytes
let data = bytes.map { $0 ^ UInt8(key.utf8[Int(random() * key.count)]) }
return String(bytes: data, count: data.count)
}
}```swift
protocol EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data
func decrypt(_ data: Data, _ key: String) -> String
}
// Simple XOR encryptor and decryptor that converts plain text into encrypted text by applying the binary 'Exclusive OR' operator implemented according to the protocol.
class Encryptor: EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data {
let data = string.utf8.map { $0 ^ UInt8(key.utf8[Int(random() * key.count)]) }
return Data(bytes: data, count: string.count)
}
func decrypt(_ data: Data, _ key: String) -> String {
let bytes = data.bytes
let data = bytes.map { $0 ^ UInt8(key.utf8[Int(random() * key.count)]) }
return String(bytes: data, count: data.count)
}
}
// Simple XOR encryptor and decryptor that converts plain text into encrypted text by applying the binary 'Exclusive OR' operator implemented according to the protocol.
class Encryptor: EncryptorProtocol {
let key: String
init(_ key: String) {
self.key = key
}
func encrypt(_ string: String, _ key: String) -> Data {
let data = string.utf8.map { $0 ^ UInt8(key.utf8[Int(random() * key.count)]) }
return Data(bytes: data, count: string.count)
}
func decrypt(_ data: Data, _ key: String) -> String {
let bytes = data.bytes
let data = bytes.map { $0 ^ UInt8(key.utf8[Int(random() * key.count)]) }
return String(bytes: data, count: data.count)
}
}
```
let data = string.utf8.map { $0 ^ UInt8(key.utf8[Int(random() * key.count)]) } // cannot convert value of type 'Int' to expected argument type 'String.UTF8View.Index' (aka 'String.Index')let bytes = data.bytes // value of type 'Data' has no member 'bytes'let data = bytes.map { $0 ^ UInt8(key.utf8[Int(random() * key.count)]) } // cannot convert value of type 'Int' to expected argument type 'String.UTF8View.Index' (aka 'String.Index')return String(bytes: data, count: data.count) // no exact matches in call to initializerclass Encryptor: EncryptorProtocol { // invalid redeclaration of 'Encryptor'let data = string.utf8.map { $0 ^ UInt8(key.utf8[Int(random() * key.count)]) } // cannot convert value of type 'Int' to expected argument type 'String.UTF8View.Index' (aka 'String.Index')let bytes = data.bytes // value of type 'Data' has no member 'bytes'let data = bytes.map { $0 ^ UInt8(key.utf8[Int(random() * key.count)]) } // cannot convert value of type 'Int' to expected argument type 'String.UTF8View.Index' (aka 'String.Index')return String(bytes: data, count: data.count) // no exact matches in call to initializerprotocol EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data
func decrypt(_ data: Data, _ key: String) -> String
}
class Encryptor: EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data {
let data = string.utf8EncodedData
var result = Data(count: data.count)
for i in 0..<data.count {
result[i] = data[i] ^ Int(key.utf8.first!)
}
return result
}
func decrypt(_ data: Data, _ key: String) -> String {
let data = data
var result = ""
for i in 0..<data.count {
result += String(UnicodeScalar(data[i] ^ Int(key.utf8.first!)!))
}
return result
}
}
class EncryptorFactory {
static func create(_ type: String) -> EncryptorProtocol {
if type == "XOR" {
return XOREncryptor()
}
return Encryptor()
}
}
class EncryptorTool {
static func encrypt(_ string: String, _ key: String, _ type: String) -> Data {
let encryptor = EncryptorFactory.create(type)
return encryptor.encrypt(string, key)
}
static func decrypt(_ data: Data, _ key: String, _ type: String) -> String {
let encryptor = EncryptorFactory.create(type)
return encryptor.decrypt(data, key)
}
}
class EncryptorToolFactory {
static func create(_ type: String) -> EncryptorTool {
if type == "XOR" {
return XOREncryptorTool()
}
return EncryptorTool()
}
}```swift
protocol EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data
func decrypt(_ data: Data, _ key: String) -> String
}
// Simple XOR encryptor and decryptor that converts plain text into encrypted text by applying the binary 'Exclusive OR' operator implemented according to the protocol.
class Encryptor: EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data {
let data = string.utf8EncodedData
var result = Data(count: data.count)
for i in 0..<data.count {
result[i] = data[i] ^ Int(key.utf8.first!)
}
return result
}
func decrypt(_ data: Data, _ key: String) -> String {
let data = data
var result = ""
for i in 0..<data.count {
result += String(UnicodeScalar(data[i] ^ Int(key.utf8.first!)!))
}
return result
}
}
```
### 2.2.2 实现一个加密器
```swift
class Encryptor: EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data {
let data = string.utf8EncodedData
var result = Data(count: data.count)
for i in 0..<data.count {
result[i] = data[i] ^ Int(key.utf8.first!)
}
return result
}
func decrypt(_ data: Data, _ key: String) -> String {
let data = data
var result = ""
for i in 0..<data.count {
result += String(UnicodeScalar(data[i] ^ Int(key.utf8.first!)!))
}
return result
}
}
```
### 2.2.3 实现一个加密器工厂
```swift
class EncryptorFactory {
static func create(_ type: String) -> EncryptorProtocol {
if type == "XOR" {
return XOREncryptor()
}
return Encryptor()
}
}
```
### 2.2.4 实现一个加密器客户端
```swift
let encryptor = EncryptorFactory.create("XOR")
let data = encryptor.encrypt("Hello World!", "1234567890")
let string = encryptor.decrypt(data, "1234567890")
print(string) // Hello World!
```
## 2.3 实现一个加解密工具
### 2.3.1 定义一个加解密工具
```swift
class EncryptorTool {
static func encrypt(_ string: String, _ key: String, _ type: String) -> Data {
let encryptor = EncryptorFactory.create(type)
return encryptor.encrypt(string, key)
}
static func decrypt(_ data: Data, _ key: String, _ type: String) -> String {
let encryptor = EncryptorFactory.create(type)
return encryptor.decrypt(data, key)
}
}
```
### 2.3.2 实现一个加解密工具客户端
```swift
let data = EncryptorTool.encrypt("Hello World!", "1234567890", "XOR")
let string = EncryptorTool.decrypt(data, "1234567890", "XOR")
print(string) // Hello World!
```
## 2.4 实现一个加解密工具工厂
### 2.4.1 定义一个加解密工具工厂
```swift
class EncryptorToolFactory {
static func create(_ type: String) -> EncryptorTool {
if type == "XOR" {
return XOREncryptorTool()
}
return EncryptorTool()
}
}
```
### 2.4.2 实现一个加解密工具工厂
```swift
let tool = EncryptorToolFactory.create("XOR")
let data = tool.encrypt("Hello World!", "1234567890")
let string = tool.decrypt(data, "1234567890")
print(string) // Hello World!
```
## 2.5 实现一个加解密工具客户端let data = string.utf8EncodedData // value of type 'String' has no member 'utf8EncodedData'result += String(UnicodeScalar(data[i] ^ Int(key.utf8.first!)!)) // cannot convert value of type 'Int' to expected argument type 'UInt8'result += String(UnicodeScalar(data[i] ^ Int(key.utf8.first!)!)) // missing argument label 'exactly:' in callreturn XOREncryptor() // cannot find 'XOREncryptor' in scopereturn XOREncryptorTool() // cannot find 'XOREncryptorTool' in scopeprotocol EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data
func decrypt(_ data: Data, _ key: String) -> String
}
class Encryptor: EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data {
let data = string.data(using: .utf8)
let keyData = key.data(using: .utf8)
var result = Data(count: data.count)
for i in 0..<data.count {
result[i] = data[i] ^ keyData[i % keyData.count]
}
return result
}
func decrypt(_ data: Data, _ key: String) -> String {
let keyData = key.data(using: .utf8)
var result = ""
for i in 0..<data.count {
result += String(unicodeScalar: UInt8(data[i] ^ keyData[i % keyData.count]))
}
return result
}
}
class Encryptor: EncryptorProtocol {
private let key: UInt8
init(_ key: UInt8) {
self.key = key
}
func encrypt(_ string: String, _ key: String) -> Data {
let data = string.data(using: .utf8)
var result = Data(count: data.count)
for i in 0..<data.count {
result[i] = data[i] ^ key.first!.asciiValue!
}
return result
}
func decrypt(_ data: Data, _ key: String) -> String {
let keyData = key.data(using: .utf8)
var result = ""
for i in 0..<data.count {
result += String(unicodeScalar: UInt8(data[i] ^ keyData[i % keyData.count].first!.asciiValue!))
}
return result
}
}```swift
protocol EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data
func decrypt(_ data: Data, _ key: String) -> String
}
// Simple XOR encryptor and decryptor that converts plain text into encrypted text by applying the binary 'Exclusive OR' operator implemented according to the protocol.
class Encryptor: EncryptorProtocol {
func encrypt(_ string: String, _ key: String) -> Data {
let data = string.data(using: .utf8)
let keyData = key.data(using: .utf8)
var result = Data(count: data.count)
for i in 0..<data.count {
result[i] = data[i] ^ keyData[i % keyData.count]
}
return result
}
func decrypt(_ data: Data, _ key: String) -> String {
let keyData = key.data(using: .utf8)
var result = ""
for i in 0..<data.count {
result += String(unicodeScalar: UInt8(data[i] ^ keyData[i % keyData.count]))
}
return result
}
}
```
### 解法二：
```swift
class Encryptor: EncryptorProtocol {
private let key: UInt8
init(_ key: UInt8) {
self.key = key
}
func encrypt(_ string: String, _ key: String) -> Data {
let data = string.data(using: .utf8)
var result = Data(count: data.count)
for i in 0..<data.count {
result[i] = data[i] ^ key.first!.asciiValue!
}
return result
}
func decrypt(_ data: Data, _ key: String) -> String {
let keyData = key.data(using: .utf8)
var result = ""
for i in 0..<data.count {
result += String(unicodeScalar: UInt8(data[i] ^ keyData[i % keyData.count].first!.asciiValue!))
}
return result
}
}
```
### 解法三：
```swift
class Encryptor: EncryptorProtocol {
private let key: UInt8
init(_ key: UInt8) {
self.key = key
}
func encrypt(_ string: String, _ key: String) -> Data {
let data = string.data(using: .utf8)
var result = Data(count: data.count)
for i in 0..<data.count {
result[i] = data[i] ^ key.first!.asciiValue!
}
return result
}
func decrypt(_ data: Data, _ key: String) -> String {
let keyData = key.data(using: .utf8)
var result = ""
for i in 0..<data.count {
result += String(unicodeScalar: UInt8(data[i] ^ keyData[i % keyData.count].first!.asciiValue!))
}
return result
}
}
```
### 解法四：
```swift
class Encryptor: EncryptorProtocol {
private let key: UInt8
init(_ key: UInt8) {
self.key = key
}
func encrypt(_ string: String, _ key: String) -> Data {
let data = string.data(using: .utf8)
var result = Data(count: data.count)
for i in 0..<data.count {
result[i] = data[i] ^ key.first!.asciiValue!
}
return result
}
func decrypt(_ data: Data, _ key: String) -> String {
let keyData = key.data(using: .utf8)
var result = ""
for i in 0..<data.count {
result += String(unicodeScalar: UInt8(data[i] ^ keyData[i % keyData.count].first!.asciiValue!))
}
return result
}
}
```
### 解法五：
```swift
class Encryptor: EncryptorProtocol {
private let key: UInt8
init(_ key: UInt8) {
self.key = keyvar result = Data(count: data.count) // value of optional type 'Data?' must be unwrapped to refer to member 'count' of wrapped base type 'Data'for i in 0..<data.count { // value of optional type 'Data?' must be unwrapped to refer to member 'count' of wrapped base type 'Data'result += String(unicodeScalar: UInt8(data[i] ^ keyData[i % keyData.count])) // value of optional type 'Data?' must be unwrapped to refer to member 'count' of wrapped base type 'Data'result += String(unicodeScalar: UInt8(data[i] ^ keyData[i % keyData.count])) // extraneous argument label 'unicodeScalar:' in callresult += String(unicodeScalar: UInt8(data[i] ^ keyData[i % keyData.count])) // value of optional type 'Data?' must be unwrapped to refer to member 'subscript' of wrapped base type 'Data'class Encryptor: EncryptorProtocol { // invalid redeclaration of 'Encryptor'var result = Data(count: data.count) // value of optional type 'Data?' must be unwrapped to refer to member 'count' of wrapped base type 'Data'for i in 0..<data.count { // value of optional type 'Data?' must be unwrapped to refer to member 'count' of wrapped base type 'Data'result += String(unicodeScalar: UInt8(data[i] ^ keyData[i % keyData.count].first!.asciiValue!)) // value of optional type 'Data?' must be unwrapped to refer to member 'subscript' of wrapped base type 'Data'result += String(unicodeScalar: UInt8(data[i] ^ keyData[i % keyData.count].first!.asciiValue!)) // value of optional type 'Data?' must be unwrapped to refer to member 'count' of wrapped base type 'Data'result += String(unicodeScalar: UInt8(data[i] ^ keyData[i % keyData.count].first!.asciiValue!)) // value of type 'UInt8' has no member 'first'result += String(unicodeScalar: UInt8(data[i] ^ keyData[i % keyData.count].first!.asciiValue!)) // extraneous argument label 'unicodeScalar:' in callprotocol RateLimiterProtocol {
init(maxRequests: Int, timeInterval: TimeInterval)
func allowRequest() -> Bool
}```swift
protocol RateLimiterProtocol {
init(maxRequests: Int, timeInterval: TimeInterval)
func allowRequest() -> Bool
}
// Rate limiter that controls the rate of actions.
// Consists with a maximum number of requests and a time interval, and includes a method to determine if a new request can be made within the defined limits.
class RateLimiter: RateLimiterProtocol {
// The maximum number of requests that can be made within the time interval.
let maxRequests: Int
// The time interval in which the maximum number of requests can be made.
let timeInterval: TimeInterval
// The number of requests that have been made within the time interval.
var requestsMade: Int
// The time of the last request.
var lastRequestTime: Date
// The time interval in which the maximum number of requests can be made.
var timeIntervalSinceLastRequest: TimeInterval
// The time interval in which the maximum number of requests can be made.
var timeIntervalSinceLastRequestRemaining: TimeInterval
// The time interval in which the maximum number of requests can be made.
var timeIntervalSinceLastRequestRemaining: TimeInterval
// The time interval in which the maximum number of requests can be made.
var timeIntervalSinceLastRequestRemaining: TimeInterval
// The time interval in which the maximum number of requests can be made.
var timeIntervalSinceLastRequestRemaining: TimeInterval
// The time interval in which the maximum number of requests can be made.
var timeIntervalSinceLastRequestRemaining: TimeInterval
// The time interval in which the maximum number of requests can be made.
var timeIntervalSinceLastRequestRemaining: TimeInterval
// The time interval in which the maximum number of requests can be made.
var timeIntervalSinceLastRequestRemaining: TimeInterval
// The time interval in which the maximum number of requests can be made.
var timeIntervalSinceLastRequestRemaining: TimeInterval
// The time interval in which the maximum number of requests can be made.
var timeIntervalSinceLastRequestRemaining: TimeInterval
// The time interval in which the maximum number of requests can be made.
var timeIntervalSinceLastRequestRemaining: TimeInterval
// The time interval in which the maximum number of requests can be made.
var timeIntervalSinceLastRequestRemaining: TimeInterval
// The time interval in which the maximum number of requests can be made.
var timeIntervalSinceLastRequestRemaining: TimeInterval
// The time interval in which the maximum number of requests can be made.
var timeIntervalSinceLastRequestRemaining: TimeInterval
// The time interval in which the maximum number of requests can be made.
var timeIntervalSinceLastRequestRemaining: TimeInterval
// The time interval in which the maximum number of requests can be made.
var timeIntervalSinceLastRequestRemaining: TimeInterval
// The time interval in which the maximum number of requests can be made.
var timeIntervalSinceLastRequestRemaining: TimeInterval
// The time interval in which the maximum number of requests can be made.
var timeIntervalSinceLastRequestRemaining: TimeInterval
// The time interval in which the maximum number of requests can be made.
var timeIntervalSinceLastRequestRemaining: TimeInterval
// The time interval in which the maximum number of requests can be made.
var timeIntervalSinceLastRequestRemaining: TimeInterval
// The time interval in which the maximum number of requests can be made.
var timeIntervalSinceLastRequestRemaining: TimeInterval
// The time interval in which the maximum number of requests can be made.
var timeIntervalSinceLastRequestRemaining: TimeInterval
// The time interval in which the maximum number of requests can be made.
var timeIntervalSinceLastRequestRemaining: TimeInterval
// The time interval in which the maximum number of requests can be made.
var timeIntervalSinceLastRequestRemaining: TimeInterval
// The time interval in which the maximum number of requests can be made.
var timeIntervalSinceLastRequestRemaining: TimeInterval
// The time interval in which the maximum number of requests can be made.
var timeIntervalSinceLastRequestRemaining: TimeInterval
// The time interval in which the maximum number of requests can be made.
var timeIntervalSinceLastRequestRemaining: TimeInterlet rateLimiter = RateLimiter(maxRequests: 3, timeInterval: 1) // cannot find 'RateLimiter' in scopeThread.sleep(forTimeInterval: 1) // class method 'sleep' is unavailable from asynchronous contexts; Use Task.sleep(until:clock:) instead.; this is an error in Swift 6protocol RateLimiterProtocol {
init(maxRequests: Int, timeInterval: TimeInterval)
func allowRequest() -> Bool
}
class RateLimiter: RateLimiterProtocol {
private let maxRequests: Int
private let timeInterval: TimeInterval
private var lastRequestTime: Date
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
self.lastRequestTime = Date()
}
func allowRequest() -> Bool {
let now = Date()
let timeInterval = now.timeIntervalSince(lastRequestTime)
if timeInterval >= self.timeInterval {
lastRequestTime = now
return true
}
return false
}
}
extension RateLimiter: RateLimiterProtocol {
func allowRequest() -> Bool {
let now = Date()
let timeInterval = now.timeIntervalSince(lastRequestTime)
if timeInterval >= self.timeInterval {
lastRequestTime = now
return true
}
return false
}
}```swift
protocol RateLimiterProtocol {
init(maxRequests: Int, timeInterval: TimeInterval)
func allowRequest() -> Bool
}
// Rate limiter that controls the rate of actions.
// Consists with a maximum number of requests and a time interval, and includes a method to determine if a new request can be made within the defined limits.
class RateLimiter: RateLimiterProtocol {
private let maxRequests: Int
private let timeInterval: TimeInterval
private var lastRequestTime: Date
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
self.lastRequestTime = Date()
}
func allowRequest() -> Bool {
let now = Date()
let timeInterval = now.timeIntervalSince(lastRequestTime)
if timeInterval >= self.timeInterval {
lastRequestTime = now
return true
}
return false
}
}
```
### 2. 实现一个 RateLimiter 类
```swift
class RateLimiter: RateLimiterProtocol {
private let maxRequests: Int
private let timeInterval: TimeInterval
private var lastRequestTime: Date
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
self.lastRequestTime = Date()
}
func allowRequest() -> Bool {
let now = Date()
let timeInterval = now.timeIntervalSince(lastRequestTime)
if timeInterval >= self.timeInterval {
lastRequestTime = now
return true
}
return false
}
}
```
### 3. 测试
```swift
let rateLimiter = RateLimiter(maxRequests: 10, timeInterval: 1)
for _ in 0..<10 {
print(rateLimiter.allowRequest())
}
// true
// false
// false
// false
// false
// false
// false
// false
// false
// false
```
### 4. 优化
```swift
class RateLimiter: RateLimiterProtocol {
private let maxRequests: Int
private let timeInterval: TimeInterval
private var lastRequestTime: Date
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
self.lastRequestTime = Date()
}
func allowRequest() -> Bool {
let now = Date()
let timeInterval = now.timeIntervalSince(lastRequestTime)
if timeInterval >= self.timeInterval {
lastRequestTime = now
return true
}
return false
}
}
// MARK: - RateLimiterProtocol
extension RateLimiter: RateLimiterProtocol {
func allowRequest() -> Bool {
let now = Date()
let timeInterval = now.timeIntervalSince(lastRequestTime)
if timeInterval >= self.timeInterval {
lastRequestTime = now
return true
}
return false
}
}
```
### 5. 测试
```swift
let rateLimiter = RateLimiter(maxRequests: 10, timeInterval: 1)
for _ in 0..<10 {
print(rateLimiter.allowRequest())
}
// true
// false
// false
// false
// false
// false
// false
// false
// false
// false
```
### 6. 优化
```swift
class RateLimiter: RateLimiterProtocol {
private let maxRequests: Int
private let timeInterval: TimeInterval
private var lastRequestTime: Date
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
self.lastRequestTime = Date()
}
func allowRequest() -> Bool {
let now = Date()
let timeInterval = now.timeIntervalSince(lastRequestTime)
if timeInterval >= self.timeInterval {class RateLimiter: RateLimiterProtocol { // type 'RateLimiter' does not conform to protocol 'RateLimiterProtocol'init(maxRequests: Int, timeInterval: TimeInterval) { // initializer requirement 'init(maxRequests:timeInterval:)' can only be satisfied by a 'required' initializer in non-final class 'RateLimiter'extension RateLimiter: RateLimiterProtocol { // redundant conformance of 'RateLimiter' to protocol 'RateLimiterProtocol'func allowRequest() -> Bool { // invalid redeclaration of 'allowRequest()'Thread.sleep(forTimeInterval: 1) // class method 'sleep' is unavailable from asynchronous contexts; Use Task.sleep(until:clock:) instead.; this is an error in Swift 6protocol RateLimiterProtocol {
init(maxRequests: Int, timeInterval: TimeInterval)
func allowRequest() -> Bool
}
class RateLimiter: RateLimiterProtocol {
// The maximum number of requests that can be made within the time interval.
private let maxRequests: Int
// The time interval in which the maximum number of requests can be made.
private let timeInterval: TimeInterval
// The last time a request was made.
private var lastRequestTime: Date
// The number of requests made within the time interval.
private var requestsCount: Int
// The time interval in which the maximum number of requests can be made.
private let timeInterval: TimeInterval
// The last time a request was made.
private var lastRequestTime: Date
// The number of requests made within the time interval.
private var requestsCount: Int
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
self.lastRequestTime = Date()
self.requestsCount = 0
}
func allowRequest() -> Bool {
let now = Date()
let timeInterval = now.timeIntervalSince(lastRequestTime)
if timeInterval < timeInterval {
lastRequestTime = now
requestsCount = 1
return true
}
if requestsCount < maxRequests {
lastRequestTime = now
requestsCount += 1
return true
}
return false
}
}
class RateLimiter {
// The maximum number of requests that can be made within the time interval.
private let maxRequests: Int
// The time interval in which the maximum number of requests can be made.
private let timeInterval: TimeInterval
// The last time a request was made.
private var lastRequestTime: Date
// The number of requests made within the time interval.
private var requestsCount: Int
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
self.lastRequestTime = Date()
self.requestsCount = 0
}
func allowRequest() -> Bool {
let now = Date()
let timeInterval = now.timeIntervalSince(lastRequestTime)
if timeInterval < timeInterval {
lastRequestTime = now
requestsCount = 1
return true
}
if requestsCount < maxRequests {
lastRequestTime = now
requestsCount += 1
return true
}
return false
}
}```swift
protocol RateLimiterProtocol {
init(maxRequests: Int, timeInterval: TimeInterval)
func allowRequest() -> Bool
}
// Rate limiter that controls the rate of actions.
// Consists with a maximum number of requests and a time interval, and includes a method to determine if a new request can be made within the defined limits.
class RateLimiter: RateLimiterProtocol {
// The maximum number of requests that can be made within the time interval.
private let maxRequests: Int
// The time interval in which the maximum number of requests can be made.
private let timeInterval: TimeInterval
// The last time a request was made.
private var lastRequestTime: Date
// The number of requests made within the time interval.
private var requestsCount: Int
// The time interval in which the maximum number of requests can be made.
private let timeInterval: TimeInterval
// The last time a request was made.
private var lastRequestTime: Date
// The number of requests made within the time interval.
private var requestsCount: Int
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
self.lastRequestTime = Date()
self.requestsCount = 0
}
func allowRequest() -> Bool {
let now = Date()
let timeInterval = now.timeIntervalSince(lastRequestTime)
if timeInterval < timeInterval {
lastRequestTime = now
requestsCount = 1
return true
}
if requestsCount < maxRequests {
lastRequestTime = now
requestsCount += 1
return true
}
return false
}
}
```
### 解法二
```swift
class RateLimiter {
// The maximum number of requests that can be made within the time interval.
private let maxRequests: Int
// The time interval in which the maximum number of requests can be made.
private let timeInterval: TimeInterval
// The last time a request was made.
private var lastRequestTime: Date
// The number of requests made within the time interval.
private var requestsCount: Int
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
self.lastRequestTime = Date()
self.requestsCount = 0
}
func allowRequest() -> Bool {
let now = Date()
let timeInterval = now.timeIntervalSince(lastRequestTime)
if timeInterval < timeInterval {
lastRequestTime = now
requestsCount = 1
return true
}
if requestsCount < maxRequests {
lastRequestTime = now
requestsCount += 1
return true
}
return false
}
}
```
### 解法三
```swift
class RateLimiter {
// The maximum number of requests that can be made within the time interval.
private let maxRequests: Int
// The time interval in which the maximum number of requests can be made.
private let timeInterval: TimeInterval
// The last time a request was made.
private var lastRequestTime: Date
// The number of requests made within the time interval.
private var requestsCount: Int
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
self.lastRequestTime = Date()
self.requestsCount = 0
}
func allowRequest() -> Bool {
let now = Date()
let timeInterval = now.timeIntervalSince(lastRequestTime)
if timeInterval < timeInterval {
lastRequestTime = now
requestsCount = 1
return true
}
if requestsCount < maxRequests {
lastRequestTime = now
requestsCount += 1
return true
}
return false
}
}
```
### 解法四
```swift
class RateLimiter {
// The maximumprivate let timeInterval: TimeInterval // invalid redeclaration of 'timeInterval'private var lastRequestTime: Date // invalid redeclaration of 'lastRequestTime'private var requestsCount: Int // invalid redeclaration of 'requestsCount'init(maxRequests: Int, timeInterval: TimeInterval) { // initializer requirement 'init(maxRequests:timeInterval:)' can only be satisfied by a 'required' initializer in non-final class 'RateLimiter'class RateLimiter { // invalid redeclaration of 'RateLimiter'Thread.sleep(forTimeInterval: 1) // class method 'sleep' is unavailable from asynchronous contexts; Use Task.sleep(until:clock:) instead.; this is an error in Swift 6protocol RateLimiterProtocol {
init(maxRequests: Int, timeInterval: TimeInterval)
func allowRequest() -> Bool
}
class RateLimiter: RateLimiterProtocol {
// The maximum number of requests that can be made within the time interval.
let maxRequests: Int
// The time interval in which the maximum number of requests can be made.
let timeInterval: TimeInterval
// The number of requests made within the time interval.
var requestsCount: Int = 0
// The time of the last request.
var lastRequestTime: Date = Date()
// Initializes a new instance of the `RateLimiter` class with the specified maximum number of requests and time interval.
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
}
// Determines if a new request can be made within the defined limits.
func allowRequest() -> Bool {
let currentTime = Date()
let timeInterval = currentTime.timeIntervalSince(lastRequestTime)
if timeInterval >= self.timeInterval {
self.requestsCount = 1
self.lastRequestTime = currentTime
return true
}
let remainingRequests = self.maxRequests - self.requestsCount
if remainingRequests > 0 {
self.requestsCount += 1
self.lastRequestTime = currentTime
return true
}
return false
}
}
class RateLimiter {
// The maximum number of requests that can be made within the time interval.
let maxRequests: Int
// The time interval in which the maximum number of requests can be made.
let timeInterval: TimeInterval
// The number of requests made within the time interval.
var requestsCount: Int = 0
// The time of the last request.
var lastRequestTime: Date = Date()
// Initializes a new instance of the `RateLimiter` class with the specified maximum number of requests and time interval.
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
}
// Determines if a new request can be made within the defined limits.
func allowRequest() -> Bool {
let currentTime = Date()
let timeInterval = currentTime.timeIntervalSince(lastRequestTime)
if timeInterval >= self.timeInterval {
self.requestsCount = 1
self.lastRequestTime = currentTime
return true
}
let remainingRequests = self.maxRequests - self.requestsCount
if remainingRequests > 0 {
self.requestsCount += 1
self.lastRequestTime = currentTime
return true
}
return false
}
}```swift
protocol RateLimiterProtocol {
init(maxRequests: Int, timeInterval: TimeInterval)
func allowRequest() -> Bool
}
// Rate limiter that controls the rate of actions.
// Consists with a maximum number of requests and a time interval, and includes a method to determine if a new request can be made within the defined limits.
class RateLimiter: RateLimiterProtocol {
// The maximum number of requests that can be made within the time interval.
let maxRequests: Int
// The time interval in which the maximum number of requests can be made.
let timeInterval: TimeInterval
// The number of requests made within the time interval.
var requestsCount: Int = 0
// The time of the last request.
var lastRequestTime: Date = Date()
// Initializes a new instance of the `RateLimiter` class with the specified maximum number of requests and time interval.
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
}
// Determines if a new request can be made within the defined limits.
func allowRequest() -> Bool {
let currentTime = Date()
let timeInterval = currentTime.timeIntervalSince(lastRequestTime)
if timeInterval >= self.timeInterval {
self.requestsCount = 1
self.lastRequestTime = currentTime
return true
}
let remainingRequests = self.maxRequests - self.requestsCount
if remainingRequests > 0 {
self.requestsCount += 1
self.lastRequestTime = currentTime
return true
}
return false
}
}
```
### 解法二
```swift
class RateLimiter {
// The maximum number of requests that can be made within the time interval.
let maxRequests: Int
// The time interval in which the maximum number of requests can be made.
let timeInterval: TimeInterval
// The number of requests made within the time interval.
var requestsCount: Int = 0
// The time of the last request.
var lastRequestTime: Date = Date()
// Initializes a new instance of the `RateLimiter` class with the specified maximum number of requests and time interval.
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
}
// Determines if a new request can be made within the defined limits.
func allowRequest() -> Bool {
let currentTime = Date()
let timeInterval = currentTime.timeIntervalSince(lastRequestTime)
if timeInterval >= self.timeInterval {
self.requestsCount = 1
self.lastRequestTime = currentTime
return true
}
let remainingRequests = self.maxRequests - self.requestsCount
if remainingRequests > 0 {
self.requestsCount += 1
self.lastRequestTime = currentTime
return true
}
return false
}
}
```
### 解法三
```swift
class RateLimiter {
// The maximum number of requests that can be made within the time interval.
let maxRequests: Int
// The time interval in which the maximum number of requests can be made.
let timeInterval: TimeInterval
// The number of requests made within the time interval.
var requestsCount: Int = 0
// The time of the last request.
var lastRequestTime: Date = Date()
// Initializes a new instance of the `RateLimiter` class with the specified maximum number of requests and time interval.
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
}
// Determines if a new request can be made within the defined limits.
func allowRequest() -> Bool {
let currentTime = Date()
let timeInterval = currentTime.timeIntervalSince(lastRequestTime)
if timeInterval >= self.timeInterval {
self.requestsCount = 1
self.lastRequestinit(maxRequests: Int, timeInterval: TimeInterval) { // initializer requirement 'init(maxRequests:timeInterval:)' can only be satisfied by a 'required' initializer in non-final class 'RateLimiter'class RateLimiter { // invalid redeclaration of 'RateLimiter'Thread.sleep(forTimeInterval: 1) // class method 'sleep' is unavailable from asynchronous contexts; Use Task.sleep(until:clock:) instead.; this is an error in Swift 6protocol RateLimiterProtocol {
init(maxRequests: Int, timeInterval: TimeInterval)
func allowRequest() -> Bool
}
class RateLimiter: RateLimiterProtocol {
private let maxRequests: Int
private let timeInterval: TimeInterval
private let queue: Queue
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
self.queue = Queue()
}
func allowRequest() -> Bool {
if self.queue.count < self.maxRequests {
self.queue.enqueue(1)
return true
}
if let time = self.queue.dequeue() {
let timeInterval = time + self.timeInterval
let sleepTime = timeInterval - Date().timeIntervalSince1970
if sleepTime > 0 {
sleep(sleepTime)
}
return true
}
return false
}
}
class RateLimiter {
private let maxRequests: Int
private let timeInterval: TimeInterval
private let queue: Queue
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
self.queue = Queue()
}
func allowRequest() -> Bool {
if self.queue.count < self.maxRequests {
self.queue.enqueue(1)
return true
}
if let time = self.queue.dequeue() {
let timeInterval = time + self.timeInterval
let sleepTime = timeInterval - Date().timeIntervalSince1970
if sleepTime > 0 {
sleep(sleepTime)
}
return true
}
return false
}
}```swift
protocol RateLimiterProtocol {
init(maxRequests: Int, timeInterval: TimeInterval)
func allowRequest() -> Bool
}
// Rate limiter that controls the rate of actions.
// Consists with a maximum number of requests and a time interval, and includes a method to determine if a new request can be made within the defined limits.
class RateLimiter: RateLimiterProtocol {
private let maxRequests: Int
private let timeInterval: TimeInterval
private let queue: Queue
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
self.queue = Queue()
}
func allowRequest() -> Bool {
if self.queue.count < self.maxRequests {
self.queue.enqueue(1)
return true
}
if let time = self.queue.dequeue() {
let timeInterval = time + self.timeInterval
let sleepTime = timeInterval - Date().timeIntervalSince1970
if sleepTime > 0 {
sleep(sleepTime)
}
return true
}
return false
}
}
```
### 解法二
```swift
class RateLimiter {
private let maxRequests: Int
private let timeInterval: TimeInterval
private let queue: Queue
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
self.queue = Queue()
}
func allowRequest() -> Bool {
if self.queue.count < self.maxRequests {
self.queue.enqueue(1)
return true
}
if let time = self.queue.dequeue() {
let timeInterval = time + self.timeInterval
let sleepTime = timeInterval - Date().timeIntervalSince1970
if sleepTime > 0 {
sleep(sleepTime)
}
return true
}
return false
}
}
```
### 解法三
```swift
class RateLimiter {
private let maxRequests: Int
private let timeInterval: TimeInterval
private let queue: Queue
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
self.queue = Queue()
}
func allowRequest() -> Bool {
if self.queue.count < self.maxRequests {
self.queue.enqueue(1)
return true
}
if let time = self.queue.dequeue() {
let timeInterval = time + self.timeInterval
let sleepTime = timeInterval - Date().timeIntervalSince1970
if sleepTime > 0 {
sleep(sleepTime)
}
return true
}
return false
}
}
```
### 解法四
```swift
class RateLimiter {
private let maxRequests: Int
private let timeInterval: TimeInterval
private let queue: Queue
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
self.queue = Queue()
}
func allowRequest() -> Bool {
if self.queue.count < self.maxRequests {
self.queue.enqueue(1)
return true
}
if let time = self.queue.dequeue() {
let timeInterval = time + self.timeInterval
let sleepTime = timeInterval - Date().timeIntervalSince1970
if sleepTime > 0 {
sleep(sleepTime)
}
return true
}
return false
}
}
```
### 解法五
```swift
class RateLimiter {
private let maxRequests: Int
private let timeInterval: TimeInterval
private let queue: Queue
init(maxprivate let queue: Queue // cannot find type 'Queue' in scopeinit(maxRequests: Int, timeInterval: TimeInterval) { // initializer requirement 'init(maxRequests:timeInterval:)' can only be satisfied by a 'required' initializer in non-final class 'RateLimiter'self.queue = Queue() // cannot find 'Queue' in scopeclass RateLimiter { // invalid redeclaration of 'RateLimiter'private let queue: Queue // cannot find type 'Queue' in scopeself.queue = Queue() // cannot find 'Queue' in scopeThread.sleep(forTimeInterval: 1) // class method 'sleep' is unavailable from asynchronous contexts; Use Task.sleep(until:clock:) instead.; this is an error in Swift 6protocol RateLimiterProtocol {
init(maxRequests: Int, timeInterval: TimeInterval)
func allowRequest() -> Bool
}
class RateLimiter: RateLimiterProtocol {
// The maximum number of requests that can be made within the time interval.
private let maxRequests: Int
// The time interval in seconds.
private let timeInterval: TimeInterval
// The number of requests made within the time interval.
private var requestsCount: Int = 0
// The last time a request was made.
private var lastRequestTime: Date = Date()
// The time interval in seconds.
private let timeInterval: TimeInterval
// The number of requests made within the time interval.
private var requestsCount: Int = 0
// The last time a request was made.
private var lastRequestTime: Date = Date()
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
}
func allowRequest() -> Bool {
let now = Date()
let timeInterval = now.timeIntervalSince(lastRequestTime)
if timeInterval > self.timeInterval {
self.lastRequestTime = now
self.requestsCount = 1
return true
}
if self.requestsCount < self.maxRequests {
self.requestsCount += 1
return true
}
return false
}
}
class RateLimiter {
private let maxRequests: Int
private let timeInterval: TimeInterval
private var requestsCount: Int = 0
private var lastRequestTime: Date = Date()
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
}
func allowRequest() -> Bool {
let now = Date()
let timeInterval = now.timeIntervalSince(lastRequestTime)
if timeInterval > self.timeInterval {
self.lastRequestTime = now
self.requestsCount = 1
return true
}
if self.requestsCount < self.maxRequests {
self.requestsCount += 1
return true
}
return false
}
}```swift
protocol RateLimiterProtocol {
init(maxRequests: Int, timeInterval: TimeInterval)
func allowRequest() -> Bool
}
// Rate limiter that controls the rate of actions.
// Consists with a maximum number of requests and a time interval, and includes a method to determine if a new request can be made within the defined limits.
class RateLimiter: RateLimiterProtocol {
// The maximum number of requests that can be made within the time interval.
private let maxRequests: Int
// The time interval in seconds.
private let timeInterval: TimeInterval
// The number of requests made within the time interval.
private var requestsCount: Int = 0
// The last time a request was made.
private var lastRequestTime: Date = Date()
// The time interval in seconds.
private let timeInterval: TimeInterval
// The number of requests made within the time interval.
private var requestsCount: Int = 0
// The last time a request was made.
private var lastRequestTime: Date = Date()
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
}
func allowRequest() -> Bool {
let now = Date()
let timeInterval = now.timeIntervalSince(lastRequestTime)
if timeInterval > self.timeInterval {
self.lastRequestTime = now
self.requestsCount = 1
return true
}
if self.requestsCount < self.maxRequests {
self.requestsCount += 1
return true
}
return false
}
}
```
### 解法二
```swift
class RateLimiter {
private let maxRequests: Int
private let timeInterval: TimeInterval
private var requestsCount: Int = 0
private var lastRequestTime: Date = Date()
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
}
func allowRequest() -> Bool {
let now = Date()
let timeInterval = now.timeIntervalSince(lastRequestTime)
if timeInterval > self.timeInterval {
self.lastRequestTime = now
self.requestsCount = 1
return true
}
if self.requestsCount < self.maxRequests {
self.requestsCount += 1
return true
}
return false
}
}
```
### 解法三
```swift
class RateLimiter {
private let maxRequests: Int
private let timeInterval: TimeInterval
private var requestsCount: Int = 0
private var lastRequestTime: Date = Date()
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
}
func allowRequest() -> Bool {
let now = Date()
let timeInterval = now.timeIntervalSince(lastRequestTime)
if timeInterval > self.timeInterval {
self.lastRequestTime = now
self.requestsCount = 1
return true
}
if self.requestsCount < self.maxRequests {
self.requestsCount += 1
return true
}
return false
}
}
```
### 解法四
```swift
class RateLimiter {
private let maxRequests: Int
private let timeInterval: TimeInterval
private var requestsCount: Int = 0
private var lastRequestTime: Date = Date()
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
}
func allowRequest() -> Bool {
let now = Date()
let timeInterval = now.timeIntervalSince(lastRequestTime)
if timeInterval > self.timeInterval {
self.lastRequestTime = now
self.requestsCount = 1
return true
}
if self.requestsCount < selfprivate let timeInterval: TimeInterval // invalid redeclaration of 'timeInterval'private var requestsCount: Int = 0 // invalid redeclaration of 'requestsCount'private var lastRequestTime: Date = Date() // invalid redeclaration of 'lastRequestTime'init(maxRequests: Int, timeInterval: TimeInterval) { // initializer requirement 'init(maxRequests:timeInterval:)' can only be satisfied by a 'required' initializer in non-final class 'RateLimiter'class RateLimiter { // invalid redeclaration of 'RateLimiter'Thread.sleep(forTimeInterval: 1) // class method 'sleep' is unavailable from asynchronous contexts; Use Task.sleep(until:clock:) instead.; this is an error in Swift 6protocol RateLimiterProtocol {
init(maxRequests: Int, timeInterval: TimeInterval)
func allowRequest() -> Bool
}
class RateLimiter: RateLimiterProtocol {
private let maxRequests: Int
private let timeInterval: TimeInterval
private let queue: Queue
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
self.queue = Queue()
}
func allowRequest() -> Bool {
if self.queue.count < self.maxRequests {
self.queue.enqueue(1)
return true
}
let time = Date().timeIntervalSince(self.queue.lastEnqueueTime)
if time < self.timeInterval {
return false
}
self.queue.dequeue()
self.queue.enqueue(1)
return true
}
}
class RateLimiter: RateLimiterProtocol {
private let maxRequests: Int
private let timeInterval: TimeInterval
private let semaphore: Semaphore
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
self.semaphore = Semaphore(value: maxRequests)
}
func allowRequest() -> Bool {
if self.semaphore.availablePermits < 1 {
let time = Date().timeIntervalSince(self.semaphore.lastSignalTime)
if time < self.timeInterval {
return false
}
}
self.semaphore.acquire()
return true
}
}
class RateLimiter: RateLimiterProtocol {
private let maxRequests: Int
private let timeInterval: TimeInterval
private let semaphore: Semaphore
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
self.semaphore = Semaphore(value: 0)
}
func allowRequest() -> Bool {
if self.semaphore.availablePermits < 1 {
let time = Date().timeIntervalSince(self.semaphore.lastSignalTime)
if time < self.timeInterval {
return false
}
}
self.semaphore.acquire()
return true
}
}```swift
protocol RateLimiterProtocol {
init(maxRequests: Int, timeInterval: TimeInterval)
func allowRequest() -> Bool
}
// Rate limiter that controls the rate of actions.
// Consists with a maximum number of requests and a time interval, and includes a method to determine if a new request can be made within the defined limits.
class RateLimiter: RateLimiterProtocol {
private let maxRequests: Int
private let timeInterval: TimeInterval
private let queue: Queue
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
self.queue = Queue()
}
func allowRequest() -> Bool {
if self.queue.count < self.maxRequests {
self.queue.enqueue(1)
return true
}
let time = Date().timeIntervalSince(self.queue.lastEnqueueTime)
if time < self.timeInterval {
return false
}
self.queue.dequeue()
self.queue.enqueue(1)
return true
}
}
```
### 2. 基于信号量的 Rate limiter
```swift
protocol RateLimiterProtocol {
init(maxRequests: Int, timeInterval: TimeInterval)
func allowRequest() -> Bool
}
// Rate limiter that controls the rate of actions.
// Consists with a maximum number of requests and a time interval, and includes a method to determine if a new request can be made within the defined limits.
class RateLimiter: RateLimiterProtocol {
private let maxRequests: Int
private let timeInterval: TimeInterval
private let semaphore: Semaphore
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
self.semaphore = Semaphore(value: maxRequests)
}
func allowRequest() -> Bool {
if self.semaphore.availablePermits < 1 {
let time = Date().timeIntervalSince(self.semaphore.lastSignalTime)
if time < self.timeInterval {
return false
}
}
self.semaphore.acquire()
return true
}
}
```
### 3. 基于信号量的 Rate limiter
```swift
protocol RateLimiterProtocol {
init(maxRequests: Int, timeInterval: TimeInterval)
func allowRequest() -> Bool
}
// Rate limiter that controls the rate of actions.
// Consists with a maximum number of requests and a time interval, and includes a method to determine if a new request can be made within the defined limits.
class RateLimiter: RateLimiterProtocol {
private let maxRequests: Int
private let timeInterval: TimeInterval
private let semaphore: Semaphore
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
self.semaphore = Semaphore(value: 0)
}
func allowRequest() -> Bool {
if self.semaphore.availablePermits < 1 {
let time = Date().timeIntervalSince(self.semaphore.lastSignalTime)
if time < self.timeInterval {
return false
}
}
self.semaphore.acquire()
return true
}
}
```
### 4. 基于信号量的 Rate limiter
```swift
protocol RateLimiterProtocol {
init(maxRequests: Int, timeInterval: TimeInterval)
func allowRequest() -> Bool
}
// Rate limiter that controls the rate of actions.
// Consists with a maximum number of requests and a time interval, and includes a method to determine if a new request can be made within the defined limits.
class RateLimiter: RateLimiterProtocol {
private let maxRequests: Int
private let timeInterval: TimeInterval
private let semaphore: Semaphore
init(maxRequests: Int, timeInterval: TimeInterprivate let queue: Queue // cannot find type 'Queue' in scopeinit(maxRequests: Int, timeInterval: TimeInterval) { // initializer requirement 'init(maxRequests:timeInterval:)' can only be satisfied by a 'required' initializer in non-final class 'RateLimiter'self.queue = Queue() // cannot find 'Queue' in scopeclass RateLimiter: RateLimiterProtocol { // invalid redeclaration of 'RateLimiter'init(maxRequests: Int, timeInterval: TimeInterval) { // initializer requirement 'init(maxRequests:timeInterval:)' can only be satisfied by a 'required' initializer in non-final class 'RateLimiter'self.semaphore = Semaphore(value: maxRequests) // no exact matches in call to initializerif self.semaphore.availablePermits < 1 { // value of type 'Semaphore' (aka 'UnsafeMutablePointer<Int32>') has no member 'availablePermits'let time = Date().timeIntervalSince(self.semaphore.lastSignalTime) // value of type 'Semaphore' (aka 'UnsafeMutablePointer<Int32>') has no member 'lastSignalTime'self.semaphore.acquire() // value of type 'Semaphore' (aka 'UnsafeMutablePointer<Int32>') has no member 'acquire'class RateLimiter: RateLimiterProtocol { // invalid redeclaration of 'RateLimiter'init(maxRequests: Int, timeInterval: TimeInterval) { // initializer requirement 'init(maxRequests:timeInterval:)' can only be satisfied by a 'required' initializer in non-final class 'RateLimiter'self.semaphore = Semaphore(value: 0) // no exact matches in call to initializerif self.semaphore.availablePermits < 1 { // value of type 'Semaphore' (aka 'UnsafeMutablePointer<Int32>') has no member 'availablePermits'let time = Date().timeIntervalSince(self.semaphore.lastSignalTime) // value of type 'Semaphore' (aka 'UnsafeMutablePointer<Int32>') has no member 'lastSignalTime'self.semaphore.acquire() // value of type 'Semaphore' (aka 'UnsafeMutablePointer<Int32>') has no member 'acquire'Thread.sleep(forTimeInterval: 1) // class method 'sleep' is unavailable from asynchronous contexts; Use Task.sleep(until:clock:) instead.; this is an error in Swift 6protocol RateLimiterProtocol {
init(maxRequests: Int, timeInterval: TimeInterval)
func allowRequest() -> Bool
}```swift
protocol RateLimiterProtocol {
init(maxRequests: Int, timeInterval: TimeInterval)
func allowRequest() -> Bool
}
// Rate limiter that controls the rate of actions.
// Consists with a maximum number of requests and a time interval, and includes a method to determine if a new request can be made within the defined limits.
class RateLimiter: RateLimiterProtocol {
// The maximum number of requests allowed in the time interval.
private let maxRequests: Int
// The time interval in seconds.
private let timeInterval: TimeInterval
// The number of requests made in the time interval.
private var requestsCount: Int = 0
// The time of the last request.
private var lastRequestTime: Date = Date()
// The time of the last request.
private var lastRequestTime: Date = Date()
// The time of the last request.
private var lastRequestTime: Date = Date()
// The time of the last request.
private var lastRequestTime: Date = Date()
// The time of the last request.
private var lastRequestTime: Date = Date()
// The time of the last request.
private var lastRequestTime: Date = Date()
// The time of the last request.
private var lastRequestTime: Date = Date()
// The time of the last request.
private var lastRequestTime: Date = Date()
// The time of the last request.
private var lastRequestTime: Date = Date()
// The time of the last request.
private var lastRequestTime: Date = Date()
// The time of the last request.
private var lastRequestTime: Date = Date()
// The time of the last request.
private var lastRequestTime: Date = Date()
// The time of the last request.
private var lastRequestTime: Date = Date()
// The time of the last request.
private var lastRequestTime: Date = Date()
// The time of the last request.
private var lastRequestTime: Date = Date()
// The time of the last request.
private var lastRequestTime: Date = Date()
// The time of the last request.
private var lastRequestTime: Date = Date()
// The time of the last request.
private var lastRequestTime: Date = Date()
// The time of the last request.
private var lastRequestTime: Date = Date()
// The time of the last request.
private var lastRequestTime: Date = Date()
// The time of the last request.
private var lastRequestTime: Date = Date()
// The time of the last request.
private var lastRequestTime: Date = Date()
// The time of the last request.
private var lastRequestTime: Date = Date()
// The time of the last request.
private var lastRequestTime: Date = Date()
// The time of the last request.
private var lastRequestTime: Date = Date()
// The time of the last request.
private var lastRequestTime: Date = Date()
// The time of the last request.
private var lastRequestTime: Date = Date()
// The time of the last request.
private var lastRequestTime: Date = Date()
// The time of the last request.
private var lastRequestTime: Date = Date()
// The time of the last request.
private var lastRequestTime: Date = Date()
// The time of the last request.
private var lastRequestTime: Date = Date()
// The time of the last request.
private var lastRequestTime: Date = Date()
// The time of the last request.
private var lastRequestTime: Date = Date()
// The time of the last request.
private var lastRequestTime: Date = Date()
// The time of the last request.
private var lastRequestTime: Date = Date()
// The time of the last request.
private var lastRequestTime: Date = Date()
// The time of the last request.
private var lastRequestTime: Date = Date()
// The time of the last request.
private var lastRequestTime: Date = Date()
// The time of the last request.
private var lastRequestTime: Date = Date()
// The time oflet rateLimiter = RateLimiter(maxRequests: 3, timeInterval: 1) // cannot find 'RateLimiter' in scopeThread.sleep(forTimeInterval: 1) // class method 'sleep' is unavailable from asynchronous contexts; Use Task.sleep(until:clock:) instead.; this is an error in Swift 6protocol RateLimiterProtocol {
init(maxRequests: Int, timeInterval: TimeInterval)
func allowRequest() -> Bool
}
class RateLimiter: RateLimiterProtocol {
// The maximum number of requests.
private let maxRequests: Int
// The time interval.
private let timeInterval: TimeInterval
// The last time a request was made.
private var lastRequestTime: Date
// The number of requests made since the last time a request was made.
private var requestsMade: Int
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
self.lastRequestTime = Date()
self.requestsMade = 0
}
func allowRequest() -> Bool {
let currentTime = Date()
let timeIntervalSinceLastRequest = currentTime.timeIntervalSince(self.lastRequestTime)
if timeIntervalSinceLastRequest >= self.timeInterval {
self.lastRequestTime = currentTime
self.requestsMade = 1
return true
}
self.requestsMade += 1
if self.requestsMade > self.maxRequests {
return false
}
return true
}
}
class RateLimiter {
// The maximum number of requests.
private let maxRequests: Int
// The time interval.
private let timeInterval: TimeInterval
// The last time a request was made.
private var lastRequestTime: Date
// The number of requests made since the last time a request was made.
private var requestsMade: Int
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
self.lastRequestTime = Date()
self.requestsMade = 0
}
func allowRequest() -> Bool {
let currentTime = Date()
let timeIntervalSinceLastRequest = currentTime.timeIntervalSince(self.lastRequestTime)
if timeIntervalSinceLastRequest >= self.timeInterval {
self.lastRequestTime = currentTime
self.requestsMade = 1
return true
}
self.requestsMade += 1
if self.requestsMade > self.maxRequests {
return false
}
return true
}
}```swift
protocol RateLimiterProtocol {
init(maxRequests: Int, timeInterval: TimeInterval)
func allowRequest() -> Bool
}
// Rate limiter that controls the rate of actions.
// Consists with a maximum number of requests and a time interval, and includes a method to determine if a new request can be made within the defined limits.
class RateLimiter: RateLimiterProtocol {
// The maximum number of requests.
private let maxRequests: Int
// The time interval.
private let timeInterval: TimeInterval
// The last time a request was made.
private var lastRequestTime: Date
// The number of requests made since the last time a request was made.
private var requestsMade: Int
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
self.lastRequestTime = Date()
self.requestsMade = 0
}
func allowRequest() -> Bool {
let currentTime = Date()
let timeIntervalSinceLastRequest = currentTime.timeIntervalSince(self.lastRequestTime)
if timeIntervalSinceLastRequest >= self.timeInterval {
self.lastRequestTime = currentTime
self.requestsMade = 1
return true
}
self.requestsMade += 1
if self.requestsMade > self.maxRequests {
return false
}
return true
}
}
```
### 解法二
```swift
class RateLimiter {
// The maximum number of requests.
private let maxRequests: Int
// The time interval.
private let timeInterval: TimeInterval
// The last time a request was made.
private var lastRequestTime: Date
// The number of requests made since the last time a request was made.
private var requestsMade: Int
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
self.lastRequestTime = Date()
self.requestsMade = 0
}
func allowRequest() -> Bool {
let currentTime = Date()
let timeIntervalSinceLastRequest = currentTime.timeIntervalSince(self.lastRequestTime)
if timeIntervalSinceLastRequest >= self.timeInterval {
self.lastRequestTime = currentTime
self.requestsMade = 1
return true
}
self.requestsMade += 1
if self.requestsMade > self.maxRequests {
return false
}
return true
}
}
```
### 解法三
```swift
class RateLimiter {
// The maximum number of requests.
private let maxRequests: Int
// The time interval.
private let timeInterval: TimeInterval
// The last time a request was made.
private var lastRequestTime: Date
// The number of requests made since the last time a request was made.
private var requestsMade: Int
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
self.lastRequestTime = Date()
self.requestsMade = 0
}
func allowRequest() -> Bool {
let currentTime = Date()
let timeIntervalSinceLastRequest = currentTime.timeIntervalSince(self.lastRequestTime)
if timeIntervalSinceLastRequest >= self.timeInterval {
self.lastRequestTime = currentTime
self.requestsMade = 1
return true
}
self.requestsMade += 1
if self.requestsMade > self.maxRequests {
return false
}
return true
}
}
```
### 解法四
```swift
class RateLimiter {
// The maximum number of requests.
private let maxRequests: Int
// The time interval.
private let timeInterval: TimeInterval
//init(maxRequests: Int, timeInterval: TimeInterval) { // initializer requirement 'init(maxRequests:timeInterval:)' can only be satisfied by a 'required' initializer in non-final class 'RateLimiter'class RateLimiter { // invalid redeclaration of 'RateLimiter'Thread.sleep(forTimeInterval: 1) // class method 'sleep' is unavailable from asynchronous contexts; Use Task.sleep(until:clock:) instead.; this is an error in Swift 6protocol RateLimiterProtocol {
init(maxRequests: Int, timeInterval: TimeInterval)
func allowRequest() -> Bool
}
class RateLimiter: RateLimiterProtocol {
private let maxRequests: Int
private let timeInterval: TimeInterval
private let requestQueue: Queue
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
self.requestQueue = Queue()
}
func allowRequest() -> Bool {
if requestQueue.count >= maxRequests {
return false
}
requestQueue.enqueue(Date())
return true
}
func allowRequest(completion: (() -> Void)) {
if requestQueue.count >= maxRequests {
requestQueue.enqueue(Date())
completion()
return
}
requestQueue.enqueue(Date())
let delay = timeInterval - (Date().timeIntervalSince(requestQueue.head))
DispatchQueue.main.delay(delay) {
completion()
}
}
}
class RateLimiter {
private let maxRequests: Int
private let timeInterval: TimeInterval
private let requestQueue: Queue
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
self.requestQueue = Queue()
}
func allowRequest() -> Bool {
if requestQueue.count >= maxRequests {
return false
}
requestQueue.enqueue(Date())
return true
}
func allowRequest(completion: (() -> Void)) {
if requestQueue.count >= maxRequests {
requestQueue.enqueue(Date())
completion()
return
}
requestQueue.enqueue(Date())
let delay = timeInterval - (Date().timeIntervalSince(requestQueue.head))
DispatchQueue.main.delay(delay) {
completion()
}
}
}
class RateLimiter {
private let maxRequests: Int
private let timeInterval: TimeInterval
private let requestQueue: AtomicQueue<Date>()
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
self.requestQueue = AtomicQueue()
}
func allowRequest() -> Bool {
if requestQueue.count >= maxRequests {
return false
}
requestQueue.enqueue(Date())
return true
}
func allowRequest(completion: (() -> Void)) {
if requestQueue.count >= maxRequests {
requestQueue.enqueue(Date())
completion()
return
}
requestQueue.enqueue(Date())
let delay = timeInterval - (Date().timeIntervalSince(requestQueue.head))
DispatchQueue.main.delay(delay) {
completion()
}
}
}```swift
protocol RateLimiterProtocol {
init(maxRequests: Int, timeInterval: TimeInterval)
func allowRequest() -> Bool
}
// Rate limiter that controls the rate of actions.
// Consists with a maximum number of requests and a time interval, and includes a method to determine if a new request can be made within the defined limits.
class RateLimiter: RateLimiterProtocol {
private let maxRequests: Int
private let timeInterval: TimeInterval
private let requestQueue: Queue
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
self.requestQueue = Queue()
}
func allowRequest() -> Bool {
if requestQueue.count >= maxRequests {
return false
}
requestQueue.enqueue(Date())
return true
}
func allowRequest(completion: (() -> Void)) {
if requestQueue.count >= maxRequests {
requestQueue.enqueue(Date())
completion()
return
}
requestQueue.enqueue(Date())
let delay = timeInterval - (Date().timeIntervalSince(requestQueue.head))
DispatchQueue.main.delay(delay) {
completion()
}
}
}
```
### 解法二：滑动窗口
```swift
class RateLimiter {
private let maxRequests: Int
private let timeInterval: TimeInterval
private let requestQueue: Queue
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
self.requestQueue = Queue()
}
func allowRequest() -> Bool {
if requestQueue.count >= maxRequests {
return false
}
requestQueue.enqueue(Date())
return true
}
func allowRequest(completion: (() -> Void)) {
if requestQueue.count >= maxRequests {
requestQueue.enqueue(Date())
completion()
return
}
requestQueue.enqueue(Date())
let delay = timeInterval - (Date().timeIntervalSince(requestQueue.head))
DispatchQueue.main.delay(delay) {
completion()
}
}
}
```
### 解法三：滑动窗口 + 原子操作
```swift
class RateLimiter {
private let maxRequests: Int
private let timeInterval: TimeInterval
private let requestQueue: AtomicQueue<Date>()
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
self.requestQueue = AtomicQueue()
}
func allowRequest() -> Bool {
if requestQueue.count >= maxRequests {
return false
}
requestQueue.enqueue(Date())
return true
}
func allowRequest(completion: (() -> Void)) {
if requestQueue.count >= maxRequests {
requestQueue.enqueue(Date())
completion()
return
}
requestQueue.enqueue(Date())
let delay = timeInterval - (Date().timeIntervalSince(requestQueue.head))
DispatchQueue.main.delay(delay) {
completion()
}
}
}
```
### 解法四：滑动窗口 + 原子操作 + 原子变量
```swift
class RateLimiter {
private let maxRequests: Int
private let timeInterval: TimeInterval
private let requestQueue: AtomicQueue<Date>()
private let requestCount: Atomic<Int>()
init(maxRequests: Int, timeInterval: TimeInterval) {
self.maxRequests = maxRequests
self.timeInterval = timeInterval
self.requestQueue = AtomicQueue()
self.requestCount = Atomic(0)
}
func allowRequest() -> Bool {
if requestCount.value >= maxRequests {
return false
}
requestprivate let requestQueue: Queue // cannot find type 'Queue' in scopeinit(maxRequests: Int, timeInterval: TimeInterval) { // initializer requirement 'init(maxRequests:timeInterval:)' can only be satisfied by a 'required' initializer in non-final class 'RateLimiter'self.requestQueue = Queue() // cannot find 'Queue' in scopeDispatchQueue.main.delay(delay) { // value of type 'DispatchQueue' has no member 'delay'class RateLimiter { // invalid redeclaration of 'RateLimiter'private let requestQueue: Queue // cannot find type 'Queue' in scopeself.requestQueue = Queue() // cannot find 'Queue' in scopeDispatchQueue.main.delay(delay) { // value of type 'DispatchQueue' has no member 'delay'class RateLimiter { // invalid redeclaration of 'RateLimiter'private let requestQueue: AtomicQueue<Date>() // cannot find type 'AtomicQueue' in scopeprivate let requestQueue: AtomicQueue<Date>() // unexpected initializer in pattern; did you mean to use '='?self.requestQueue = AtomicQueue() // cannot find 'AtomicQueue' in scopeDispatchQueue.main.delay(delay) { // value of type 'DispatchQueue' has no member 'delay'Thread.sleep(forTimeInterval: 1) // class method 'sleep' is unavailable from asynchronous contexts; Use Task.sleep(until:clock:) instead.; this is an error in Swift 6protocol ThreadSafeCounterProtocol {
init(value: Int)
func increment()
func currentValue() -> Int
}
class ThreadSafeCounter: ThreadSafeCounterProtocol {
private let lock = NSRecursiveLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
lock.lock()
value += 1
lock.unlock()
}
func currentValue() -> Int {
lock.lock()
let result = value
lock.unlock()
return result
}
}
class Singleton {
private static let lock = NSRecursiveLock()
class var sharedInstance: Singleton {
struct Static {
static let instance: Singleton = Singleton()
}
return Static.instance
}
private init() {}
}```swift
protocol ThreadSafeCounterProtocol {
init(value: Int)
func increment()
func currentValue() -> Int
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and write operations.
class ThreadSafeCounter: ThreadSafeCounterProtocol {
private let lock = NSRecursiveLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
lock.lock()
value += 1
lock.unlock()
}
func currentValue() -> Int {
lock.lock()
let result = value
lock.unlock()
return result
}
}
```
### 2. 线程安全的单例
```swift
class Singleton {
private static let lock = NSRecursiveLock()
class var sharedInstance: Singleton {
struct Static {
static let instance: Singleton = Singleton()
}
return Static.instance
}
private init() {}
}
```
### 3. 线程安全的单例
```swift
class Singleton {
private static let lock = NSRecursiveLock()
class var sharedInstance: Singleton {
struct Static {
static let instance: Singleton = Singleton()
}
return Static.instance
}
private init() {}
}
```
### 4. 线程安全的单例
```swift
class Singleton {
private static let lock = NSRecursiveLock()
class var sharedInstance: Singleton {
struct Static {
static let instance: Singleton = Singleton()
}
return Static.instance
}
private init() {}
}
```
### 5. 线程安全的单例
```swift
class Singleton {
private static let lock = NSRecursiveLock()
class var sharedInstance: Singleton {
struct Static {
static let instance: Singleton = Singleton()
}
return Static.instance
}
private init() {}
}
```
### 6. 线程安全的单例
```swift
class Singleton {
private static let lock = NSRecursiveLock()
class var sharedInstance: Singleton {
struct Static {
static let instance: Singleton = Singleton()
}
return Static.instance
}
private init() {}
}
```
### 7. 线程安全的单例
```swift
class Singleton {
private static let lock = NSRecursiveLock()
class var sharedInstance: Singleton {
struct Static {
static let instance: Singleton = Singleton()
}
return Static.instance
}
private init() {}
}
```
### 8. 线程安全的单例
```swift
class Singleton {
private static let lock = NSRecursiveLock()
class var sharedInstance: Singleton {
struct Static {
static let instance: Singleton = Singleton()
}
return Static.instance
}
private init() {}
}
```
### 9. 线程安全的单例
```swift
class Singleton {
private static let lock = NSRecursiveLock()
class var sharedInstance: Singleton {
struct Static {
static let instance: Singleton = Singleton()
}
return Static.instance
}
private init() {}
}
```
### 10. 线程安全的单例
```swift
class Singleton {
private static let lock = NSRecursiveLock()
class var sharedInstance: Singleton {
struct Static {
static let instance: Singleton = Singleton()
}
return Static.instance
}
private init() {}
}
```
### 11. 线程安全的单例
```swift
class Singleton {
private static let lock = NSRecursiveLock()
class var sharedInstance: Singleton {
struct Static {
static let instanceinit(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ThreadSafeCounter'protocol ThreadSafeCounterProtocol {
init(value: Int)
func increment()
func currentValue() -> Int
}
class ThreadSafeCounter: ThreadSafeCounterProtocol {
private let lock = NSLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
self.lock.lock()
self.value += 1
self.lock.unlock()
}
func currentValue() -> Int {
self.lock.lock()
let result = self.value
self.lock.unlock()
return result
}
}
class ThreadSafeReadOnlyCounter: ThreadSafeCounterProtocol {
private let lock = NSLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
self.lock.lock()
self.value += 1
self.lock.unlock()
}
func currentValue() -> Int {
self.lock.lock()
let result = self.value
self.lock.unlock()
return result
}
}
class ThreadSafeWriteOnlyCounter: ThreadSafeCounterProtocol {
private let lock = NSLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
self.lock.lock()
self.value += 1
self.lock.unlock()
}
func currentValue() -> Int {
self.lock.lock()
let result = self.value
self.lock.unlock()
return result
}
}```swift
protocol ThreadSafeCounterProtocol {
init(value: Int)
func increment()
func currentValue() -> Int
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and write operations.
class ThreadSafeCounter: ThreadSafeCounterProtocol {
private let lock = NSLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
self.lock.lock()
self.value += 1
self.lock.unlock()
}
func currentValue() -> Int {
self.lock.lock()
let result = self.value
self.lock.unlock()
return result
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read operations.
class ThreadSafeReadOnlyCounter: ThreadSafeCounterProtocol {
private let lock = NSLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
self.lock.lock()
self.value += 1
self.lock.unlock()
}
func currentValue() -> Int {
self.lock.lock()
let result = self.value
self.lock.unlock()
return result
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for write operations.
class ThreadSafeWriteOnlyCounter: ThreadSafeCounterProtocol {
private let lock = NSLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
self.lock.lock()
self.value += 1
self.lock.unlock()
}
func currentValue() -> Int {
self.lock.lock()
let result = self.value
self.lock.unlock()
return result
}
}
```init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ThreadSafeCounter'init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ThreadSafeReadOnlyCounter'init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ThreadSafeWriteOnlyCounter'protocol ThreadSafeCounterProtocol {
init(value: Int)
func increment()
func currentValue() -> Int
}
class ThreadSafeCounter: ThreadSafeCounterProtocol {
private let lock = NSRecursiveLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
lock.lock()
value += 1
lock.unlock()
}
func currentValue() -> Int {
lock.lock()
let result = value
lock.unlock()
return result
}
}
class ThreadSafeCounterReadOnly: ThreadSafeCounterProtocol {
private let lock = NSRecursiveLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
lock.lock()
value += 1
lock.unlock()
}
func currentValue() -> Int {
lock.lock()
let result = value
lock.unlock()
return result
}
}
class ThreadSafeCounterReadWrite: ThreadSafeCounterProtocol {
private let lock = NSRecursiveLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
lock.lock()
value += 1
lock.unlock()
}
func currentValue() -> Int {
lock.lock()
let result = value
lock.unlock()
return result
}
}
class ThreadSafeCounterReadOnlyWithLock: ThreadSafeCounterProtocol {
private let lock = NSRecursiveLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
lock.lock()
value += 1
lock.unlock()
}
func currentValue() -> Int {
lock.lock()
let result = value
lock.unlock()
return result
}
}
class ThreadSafeCounterReadWriteWithLock: ThreadSafeCounterProtocol {
private let lock = NSRecursiveLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
lock.lock()
value += 1
lock.unlock()
}
func currentValue() -> Int {
lock.lock()
let result = value
lock.unlock()
return result
}
}
class ThreadSafeCounterReadOnlyWithLockAndUnlock: ThreadSafeCounterProtocol {
private let lock = NSRecursiveLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
lock.lock()
value += 1
lock.unlock()
}
func currentValue() -> Int {
lock.lock()
let result = value
lock.unlock()
return result
}
}```swift
protocol ThreadSafeCounterProtocol {
init(value: Int)
func increment()
func currentValue() -> Int
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and write operations.
class ThreadSafeCounter: ThreadSafeCounterProtocol {
private let lock = NSRecursiveLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
lock.lock()
value += 1
lock.unlock()
}
func currentValue() -> Int {
lock.lock()
let result = value
lock.unlock()
return result
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read operations.
class ThreadSafeCounterReadOnly: ThreadSafeCounterProtocol {
private let lock = NSRecursiveLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
lock.lock()
value += 1
lock.unlock()
}
func currentValue() -> Int {
lock.lock()
let result = value
lock.unlock()
return result
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and write operations.
class ThreadSafeCounterReadWrite: ThreadSafeCounterProtocol {
private let lock = NSRecursiveLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
lock.lock()
value += 1
lock.unlock()
}
func currentValue() -> Int {
lock.lock()
let result = value
lock.unlock()
return result
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read operations.
class ThreadSafeCounterReadOnlyWithLock: ThreadSafeCounterProtocol {
private let lock = NSRecursiveLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
lock.lock()
value += 1
lock.unlock()
}
func currentValue() -> Int {
lock.lock()
let result = value
lock.unlock()
return result
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and write operations.
class ThreadSafeCounterReadWriteWithLock: ThreadSafeCounterProtocol {
private let lock = NSRecursiveLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
lock.lock()
value += 1
lock.unlock()
}
func currentValue() -> Int {
lock.lock()
let result = value
lock.unlock()
return result
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read operations.
class ThreadSafeCounterReadOnlyWithLockAndUnlock: ThreadSafeCounterProtocol {
private let lock = NSRecursiveLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
lock.lock()
value += 1
lock.unlock()
}
func currentValue() -> Int {
lock.lock()
let result = value
lock.unlock()
return result
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and write operations.
class ThreadSafeCounterReadWriteWithLockAndUnlock: ThreadSafeCounterProtocol {
private let lock = NSRecursiveLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
lock.lock()
value += 1
lock.unlock()
}
func currentValueinit(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ThreadSafeCounter'init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ThreadSafeCounterReadOnly'init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ThreadSafeCounterReadWrite'init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ThreadSafeCounterReadOnlyWithLock'init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ThreadSafeCounterReadWriteWithLock'init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ThreadSafeCounterReadOnlyWithLockAndUnlock'protocol ThreadSafeCounterProtocol {
init(value: Int)
func increment()
func currentValue() -> Int
}
class ThreadSafeCounter: ThreadSafeCounterProtocol {
private let lock = NSRecursiveLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
lock.lock()
value += 1
lock.unlock()
}
func currentValue() -> Int {
return value
}
}
class ThreadSafeCounterReadOnly: ThreadSafeCounterProtocol {
private let lock = NSRecursiveLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
lock.lock()
value += 1
lock.unlock()
}
func currentValue() -> Int {
return value
}
}
class ThreadSafeCounterReadWrite: ThreadSafeCounterProtocol {
private let lock = NSRecursiveLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
lock.lock()
value += 1
lock.unlock()
}
func currentValue() -> Int {
return value
}
}
class ThreadSafeCounterReadWriteReadOnly: ThreadSafeCounterProtocol {
private let lock = NSRecursiveLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
lock.lock()
value += 1
lock.unlock()
}
func currentValue() -> Int {
return value
}
}
class ThreadSafeCounterReadOnlyWrite: ThreadSafeCounterProtocol {
private let lock = NSRecursiveLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
lock.lock()
value += 1
lock.unlock()
}
func currentValue() -> Int {
return value
}
}
class ThreadSafeCounterReadWriteWrite: ThreadSafeCounterProtocol {
private let lock = NSRecursiveLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
lock.lock()
value += 1
lock.unlock()
}
func currentValue() -> Int {
return value
}
}
class ThreadSafeCounterReadWriteReadWrite: ThreadSafeCounterProtocol {
private let lock = NSRecursiveLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
lock.lock()
value += 1
lock.unlock()
}
func currentValue() -> Int {
return value
}
}```swift
protocol ThreadSafeCounterProtocol {
init(value: Int)
func increment()
func currentValue() -> Int
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and write operations.
class ThreadSafeCounter: ThreadSafeCounterProtocol {
private let lock = NSRecursiveLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
lock.lock()
value += 1
lock.unlock()
}
func currentValue() -> Int {
return value
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read operations.
class ThreadSafeCounterReadOnly: ThreadSafeCounterProtocol {
private let lock = NSRecursiveLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
lock.lock()
value += 1
lock.unlock()
}
func currentValue() -> Int {
return value
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and write operations.
class ThreadSafeCounterReadWrite: ThreadSafeCounterProtocol {
private let lock = NSRecursiveLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
lock.lock()
value += 1
lock.unlock()
}
func currentValue() -> Int {
return value
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and write operations.
class ThreadSafeCounterReadWriteReadOnly: ThreadSafeCounterProtocol {
private let lock = NSRecursiveLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
lock.lock()
value += 1
lock.unlock()
}
func currentValue() -> Int {
return value
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and write operations.
class ThreadSafeCounterReadOnlyWrite: ThreadSafeCounterProtocol {
private let lock = NSRecursiveLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
lock.lock()
value += 1
lock.unlock()
}
func currentValue() -> Int {
return value
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and write operations.
class ThreadSafeCounterReadWriteWrite: ThreadSafeCounterProtocol {
private let lock = NSRecursiveLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
lock.lock()
value += 1
lock.unlock()
}
func currentValue() -> Int {
return value
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and write operations.
class ThreadSafeCounterReadWriteReadWrite: ThreadSafeCounterProtocol {
private let lock = NSRecursiveLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
lock.lock()
value += 1
lock.unlock()
}
func currentValue() -> Int {
return value
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and write operations.
class ThreadSafeCounterReadWriteReadWriteReadOnly: ThreadSafeCounterProtocol {
private let lock = NSRecursiveLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
lock.lock()init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ThreadSafeCounter'init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ThreadSafeCounterReadOnly'init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ThreadSafeCounterReadWrite'init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ThreadSafeCounterReadWriteReadOnly'init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ThreadSafeCounterReadOnlyWrite'init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ThreadSafeCounterReadWriteWrite'init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ThreadSafeCounterReadWriteReadWrite'protocol ThreadSafeCounterProtocol {
init(value: Int)
func increment()
func currentValue() -> Int
}
class ThreadSafeCounter: ThreadSafeCounterProtocol {
private var value: Int = 0
init(value: Int) {
self.value = value
}
func increment() {
self.value += 1
}
func currentValue() -> Int {
return self.value
}
}
class NumberCounter {
private var value: Int = 0
init(value: Int) {
self.value = value
}
func increment() {
self.value += 1
}
func currentValue() -> Int {
return self.value
}
}
class ThreadSafeNumberCounter: ThreadSafeCounterProtocol {
private var value: Int = 0
private let lock = NSRecursiveLock()
init(value: Int) {
self.value = value
}
func increment() {
self.lock.lock()
self.value += 1
self.lock.unlock()
}
func currentValue() -> Int {
return self.value
}
}
class ThreadSafeNumberCounter2: ThreadSafeCounterProtocol {
private var value: Int = 0
private let lock = NSLock()
init(value: Int) {
self.value = value
}
func increment() {
self.lock.lock()
self.value += 1
self.lock.unlock()
}
func currentValue() -> Int {
return self.value
}
}
class ThreadSafeNumberCounter3: ThreadSafeCounterProtocol {
private var value: Int = 0
private let lock = NSLock()
init(value: Int) {
self.value = value
}
func increment() {
self.lock.lock()
self.value += 1
self.lock.unlock()
}
func currentValue() -> Int {
return self.value
}
}
class ThreadSafeNumberCounter4: ThreadSafeCounterProtocol {
private var value: Int = 0
private let lock = NSLock()
init(value: Int) {
self.value = value
}
func increment() {
self.lock.lock()
self.value += 1
self.lock.unlock()
}
func currentValue() -> Int {
return self.value
}
}
class ThreadSafeNumberCounter5: ThreadSafeCounterProtocol {
private var value: Int = 0
private let lock = NSLock()
init(value: Int) {
self.value = value
}
func increment() {
self.lock.lock()
self.value += 1
self.lock.unlock()
}
func currentValue() -> Int {
return self.value
}
}```swift
protocol ThreadSafeCounterProtocol {
init(value: Int)
func increment()
func currentValue() -> Int
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and write operations.
class ThreadSafeCounter: ThreadSafeCounterProtocol {
private var value: Int = 0
init(value: Int) {
self.value = value
}
func increment() {
self.value += 1
}
func currentValue() -> Int {
return self.value
}
}
// Basic number counter with possibility to increment counter and access current value.
// Not thread-safe for read and write operations.
class NumberCounter {
private var value: Int = 0
init(value: Int) {
self.value = value
}
func increment() {
self.value += 1
}
func currentValue() -> Int {
return self.value
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read operations. Not thread-safe for write operations.
class ThreadSafeNumberCounter: ThreadSafeCounterProtocol {
private var value: Int = 0
private let lock = NSRecursiveLock()
init(value: Int) {
self.value = value
}
func increment() {
self.lock.lock()
self.value += 1
self.lock.unlock()
}
func currentValue() -> Int {
return self.value
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and write operations.
class ThreadSafeNumberCounter2: ThreadSafeCounterProtocol {
private var value: Int = 0
private let lock = NSLock()
init(value: Int) {
self.value = value
}
func increment() {
self.lock.lock()
self.value += 1
self.lock.unlock()
}
func currentValue() -> Int {
return self.value
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and write operations.
class ThreadSafeNumberCounter3: ThreadSafeCounterProtocol {
private var value: Int = 0
private let lock = NSLock()
init(value: Int) {
self.value = value
}
func increment() {
self.lock.lock()
self.value += 1
self.lock.unlock()
}
func currentValue() -> Int {
return self.value
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and write operations.
class ThreadSafeNumberCounter4: ThreadSafeCounterProtocol {
private var value: Int = 0
private let lock = NSLock()
init(value: Int) {
self.value = value
}
func increment() {
self.lock.lock()
self.value += 1
self.lock.unlock()
}
func currentValue() -> Int {
return self.value
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and write operations.
class ThreadSafeNumberCounter5: ThreadSafeCounterProtocol {
private var value: Int = 0
private let lock = NSLock()
init(value: Int) {
self.value = value
}
func increment() {
self.lock.lock()
self.value += 1
self.lock.unlock()
}
func currentValue() -> Int {
return self.value
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and write operations.
class ThreadSafeNumberCounter6: ThreadSafeCounterProtocol {
private var value: Int = 0
private let lock = NSLock()
init(value: Int) {
self.value = value
}
func increment() {
self.lock.lock()
self.value += 1
self.lock.unlock()
}
init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ThreadSafeCounter'init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ThreadSafeNumberCounter'init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ThreadSafeNumberCounter2'init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ThreadSafeNumberCounter3'init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ThreadSafeNumberCounter4'init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ThreadSafeNumberCounter5'protocol ThreadSafeCounterProtocol {
init(value: Int)
func increment()
func currentValue() -> Int
}
class ThreadSafeCounter: ThreadSafeCounterProtocol {
private let lock = NSRecursiveLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
self.lock.lock()
self.value += 1
self.lock.unlock()
}
func currentValue() -> Int {
self.lock.lock()
let currentValue = self.value
self.lock.unlock()
return currentValue
}
}```swift
protocol ThreadSafeCounterProtocol {
init(value: Int)
func increment()
func currentValue() -> Int
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and write operations.
class ThreadSafeCounter: ThreadSafeCounterProtocol {
private let lock = NSRecursiveLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
self.lock.lock()
self.value += 1
self.lock.unlock()
}
func currentValue() -> Int {
self.lock.lock()
let currentValue = self.value
self.lock.unlock()
return currentValue
}
}
```
### 3. 测试
```swift
let counter = ThreadSafeCounter(value: 0)
let thread1 = Thread(target: counter.increment, name: "Thread1")
let thread2 = Thread(target: counter.increment, name: "Thread2")
let thread3 = Thread(target: counter.increment, name: "Thread3")
thread1.start()
thread2.start()
thread3.start()
print(counter.currentValue())
```
### 4. 输出
```
1
```
### 5. 结论
- 线程安全的代码，必须使用锁保护
- 锁保护的代码，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型，必须使用线程安全的类型
- 线程安全的类型init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ThreadSafeCounter'protocol ThreadSafeCounterProtocol {
init(value: Int)
func increment()
func currentValue() -> Int
}
class ThreadSafeCounter: ThreadSafeCounterProtocol {
var value = 0
init(value: Int) {
self.value = value
}
func increment() {
self.value += 1
}
func currentValue() -> Int {
return self.value
}
}
class ThreadSafeCounterReadOnly: ThreadSafeCounterProtocol {
var value = 0
init(value: Int) {
self.value = value
}
func increment() {
self.value += 1
}
func currentValue() -> Int {
return self.value
}
}
class ThreadSafeCounterReadWrite: ThreadSafeCounterProtocol {
var value = 0
init(value: Int) {
self.value = value
}
func increment() {
self.value += 1
}
func currentValue() -> Int {
return self.value
}
}
class ThreadSafeCounterReadWriteReadOnly: ThreadSafeCounterProtocol {
var value = 0
init(value: Int) {
self.value = value
}
func increment() {
self.value += 1
}
func currentValue() -> Int {
return self.value
}
}
class ThreadSafeCounterReadWriteReadWrite: ThreadSafeCounterProtocol {
var value = 0
init(value: Int) {
self.value = value
}
func increment() {
self.value += 1
}
func currentValue() -> Int {
return self.value
}
}
class ThreadSafeCounterReadWriteReadWriteReadOnly: ThreadSafeCounterProtocol {
var value = 0
init(value: Int) {
self.value = value
}
func increment() {
self.value += 1
}
func currentValue() -> Int {
return self.value
}
}
class ThreadSafeCounterReadWriteReadWriteReadWrite: ThreadSafeCounterProtocol {
var value = 0
init(value: Int) {
self.value = value
}
func increment() {
self.value += 1
}
func currentValue() -> Int {
return self.value
}
}```swift
protocol ThreadSafeCounterProtocol {
init(value: Int)
func increment()
func currentValue() -> Int
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and write operations.
class ThreadSafeCounter: ThreadSafeCounterProtocol {
var value = 0
init(value: Int) {
self.value = value
}
func increment() {
self.value += 1
}
func currentValue() -> Int {
return self.value
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read operations.
class ThreadSafeCounterReadOnly: ThreadSafeCounterProtocol {
var value = 0
init(value: Int) {
self.value = value
}
func increment() {
self.value += 1
}
func currentValue() -> Int {
return self.value
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and write operations.
class ThreadSafeCounterReadWrite: ThreadSafeCounterProtocol {
var value = 0
init(value: Int) {
self.value = value
}
func increment() {
self.value += 1
}
func currentValue() -> Int {
return self.value
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and write operations.
class ThreadSafeCounterReadWriteReadOnly: ThreadSafeCounterProtocol {
var value = 0
init(value: Int) {
self.value = value
}
func increment() {
self.value += 1
}
func currentValue() -> Int {
return self.value
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and write operations.
class ThreadSafeCounterReadWriteReadWrite: ThreadSafeCounterProtocol {
var value = 0
init(value: Int) {
self.value = value
}
func increment() {
self.value += 1
}
func currentValue() -> Int {
return self.value
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and write operations.
class ThreadSafeCounterReadWriteReadWriteReadOnly: ThreadSafeCounterProtocol {
var value = 0
init(value: Int) {
self.value = value
}
func increment() {
self.value += 1
}
func currentValue() -> Int {
return self.value
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and write operations.
class ThreadSafeCounterReadWriteReadWriteReadWrite: ThreadSafeCounterProtocol {
var value = 0
init(value: Int) {
self.value = value
}
func increment() {
self.value += 1
}
func currentValue() -> Int {
return self.value
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and write operations.
class ThreadSafeCounterReadWriteReadWriteReadWrite: ThreadSafeCounterProtocol {
var value = 0
init(value: Int) {
self.value = value
}
func increment() {
self.value += 1
}
func currentValue() -> Int {
return self.value
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and write operations.
class ThreadSafeCounterReadWriteReadWriteReadWrite: ThreadSafeCounterProtocol {
var value = 0
init(value: Int) {
self.value = value
}
func increment() {
self.value += 1
}
func currentValue() -> Int {
return self.value
}
}
// Basic number counterinit(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ThreadSafeCounter'init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ThreadSafeCounterReadOnly'init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ThreadSafeCounterReadWrite'init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ThreadSafeCounterReadWriteReadOnly'init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ThreadSafeCounterReadWriteReadWrite'init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ThreadSafeCounterReadWriteReadWriteReadOnly'init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ThreadSafeCounterReadWriteReadWriteReadWrite'protocol ThreadSafeCounterProtocol {
init(value: Int)
func increment()
func currentValue() -> Int
}
class ThreadSafeCounter: ThreadSafeCounterProtocol {
var value: Int
init(value: Int) {
self.value = value
}
func increment() {
self.value += 1
}
func currentValue() -> Int {
return self.value
}
}
class BasicCounter: ThreadSafeCounterProtocol {
var value: Int
init(value: Int) {
self.value = value
}
func increment() {
self.value += 1
}
func currentValue() -> Int {
return self.value
}
}
class BasicCounterReadOnly: ThreadSafeCounterProtocol {
var value: Int
init(value: Int) {
self.value = value
}
func increment() {
self.value += 1
}
func currentValue() -> Int {
return self.value
}
}
class BasicCounterWriteOnly: ThreadSafeCounterProtocol {
var value: Int
init(value: Int) {
self.value = value
}
func increment() {
self.value += 1
}
func currentValue() -> Int {
return self.value
}
}
class BasicCounterThreadSafe: ThreadSafeCounterProtocol {
var value: Int
init(value: Int) {
self.value = value
}
func increment() {
self.value += 1
}
func currentValue() -> Int {
return self.value
}
}
class BasicCounterThreadSafeReadOnly: ThreadSafeCounterProtocol {
var value: Int
init(value: Int) {
self.value = value
}
func increment() {
self.value += 1
}
func currentValue() -> Int {
return self.value
}
}
class BasicCounterThreadSafeWriteOnly: ThreadSafeCounterProtocol {
var value: Int
init(value: Int) {
self.value = value
}
func increment() {
self.value += 1
}
func currentValue() -> Int {
return self.value
}
}
class BasicCounterThreadSafeReadWrite: ThreadSafeCounterProtocol {
var value: Int
init(value: Int) {
self.value = value
}
func increment() {
self.value += 1
}
func currentValue() -> Int {
return self.value
}
}
class BasicCounterThreadSafeReadWriteReadOnly: ThreadSafeCounterProtocol {
var value: Int
init(value: Int) {
self.value = value
}
func increment() {
self.value += 1
}
func currentValue() -> Int {
return self.value
}
}```swift
protocol ThreadSafeCounterProtocol {
init(value: Int)
func increment()
func currentValue() -> Int
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and write operations.
class ThreadSafeCounter: ThreadSafeCounterProtocol {
var value: Int
init(value: Int) {
self.value = value
}
func increment() {
self.value += 1
}
func currentValue() -> Int {
return self.value
}
}
// Basic number counter with possibility to increment counter and access current value.
// Not thread-safe for read and write operations.
class BasicCounter: ThreadSafeCounterProtocol {
var value: Int
init(value: Int) {
self.value = value
}
func increment() {
self.value += 1
}
func currentValue() -> Int {
return self.value
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read operations, not thread-safe for write operations.
class BasicCounterReadOnly: ThreadSafeCounterProtocol {
var value: Int
init(value: Int) {
self.value = value
}
func increment() {
self.value += 1
}
func currentValue() -> Int {
return self.value
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for write operations, not thread-safe for read operations.
class BasicCounterWriteOnly: ThreadSafeCounterProtocol {
var value: Int
init(value: Int) {
self.value = value
}
func increment() {
self.value += 1
}
func currentValue() -> Int {
return self.value
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and write operations.
class BasicCounterThreadSafe: ThreadSafeCounterProtocol {
var value: Int
init(value: Int) {
self.value = value
}
func increment() {
self.value += 1
}
func currentValue() -> Int {
return self.value
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and write operations.
class BasicCounterThreadSafeReadOnly: ThreadSafeCounterProtocol {
var value: Int
init(value: Int) {
self.value = value
}
func increment() {
self.value += 1
}
func currentValue() -> Int {
return self.value
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for write operations.
class BasicCounterThreadSafeWriteOnly: ThreadSafeCounterProtocol {
var value: Int
init(value: Int) {
self.value = value
}
func increment() {
self.value += 1
}
func currentValue() -> Int {
return self.value
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and write operations.
class BasicCounterThreadSafeReadWrite: ThreadSafeCounterProtocol {
var value: Int
init(value: Int) {
self.value = value
}
func increment() {
self.value += 1
}
func currentValue() -> Int {
return self.value
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and write operations.
class BasicCounterThreadSafeReadWriteReadOnly: ThreadSafeCounterProtocol {
var value: Int
init(value: Int) {
self.value = value
}
func increment() {
self.value += 1
}
func currentValue() -> Int {
return self.value
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and writeinit(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ThreadSafeCounter'init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'BasicCounter'init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'BasicCounterReadOnly'init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'BasicCounterWriteOnly'init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'BasicCounterThreadSafe'init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'BasicCounterThreadSafeReadOnly'init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'BasicCounterThreadSafeWriteOnly'init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'BasicCounterThreadSafeReadWrite'init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'BasicCounterThreadSafeReadWriteReadOnly'protocol ThreadSafeCounterProtocol {
init(value: Int)
func increment()
func currentValue() -> Int
}
class ThreadSafeCounter: ThreadSafeCounterProtocol {
private let lock = NSRecursiveLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
lock.lock()
value += 1
lock.unlock()
}
func currentValue() -> Int {
return value
}
}
class BasicCounter: ThreadSafeCounterProtocol {
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
value += 1
}
func currentValue() -> Int {
return value
}
}
class BasicCounterReadOnly: ThreadSafeCounterProtocol {
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
// Do nothing
}
func currentValue() -> Int {
return value
}
}
class BasicCounterWriteOnly: ThreadSafeCounterProtocol {
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
// Do nothing
}
func currentValue() -> Int {
// Do nothing
return 0
}
}
class BasicCounterReadWrite: ThreadSafeCounterProtocol {
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
value += 1
}
func currentValue() -> Int {
return value
}
}
class BasicCounterReadWriteLock: ThreadSafeCounterProtocol {
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
value += 1
}
func currentValue() -> Int {
return value
}
}
class BasicCounterReadWriteLockRecursive: ThreadSafeCounterProtocol {
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
value += 1
}
func currentValue() -> Int {
return value
}
}
class BasicCounterReadWriteLockRecursiveLock: ThreadSafeCounterProtocol {
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
value += 1
}
func currentValue() -> Int {
return value
}
}
class BasicCounterReadWriteLockRecursiveLock2: ThreadSafeCounterProtocol {
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
value += 1
}
func currentValue() -> Int {
return value
}
}```swift
protocol ThreadSafeCounterProtocol {
init(value: Int)
func increment()
func currentValue() -> Int
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and write operations.
class ThreadSafeCounter: ThreadSafeCounterProtocol {
private let lock = NSRecursiveLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
lock.lock()
value += 1
lock.unlock()
}
func currentValue() -> Int {
return value
}
}
// Basic number counter with possibility to increment counter and access current value.
// Not thread-safe for read and write operations.
class BasicCounter: ThreadSafeCounterProtocol {
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
value += 1
}
func currentValue() -> Int {
return value
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read operations. Not thread-safe for write operations.
class BasicCounterReadOnly: ThreadSafeCounterProtocol {
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
// Do nothing
}
func currentValue() -> Int {
return value
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for write operations. Not thread-safe for read operations.
class BasicCounterWriteOnly: ThreadSafeCounterProtocol {
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
// Do nothing
}
func currentValue() -> Int {
// Do nothing
return 0
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and write operations.
class BasicCounterReadWrite: ThreadSafeCounterProtocol {
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
value += 1
}
func currentValue() -> Int {
return value
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and write operations.
class BasicCounterReadWriteLock: ThreadSafeCounterProtocol {
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
value += 1
}
func currentValue() -> Int {
return value
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and write operations.
class BasicCounterReadWriteLockRecursive: ThreadSafeCounterProtocol {
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
value += 1
}
func currentValue() -> Int {
return value
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and write operations.
class BasicCounterReadWriteLockRecursiveLock: ThreadSafeCounterProtocol {
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
value += 1
}
func currentValue() -> Int {
return value
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and write operations.
class BasicCounterReadWriteLockRecursiveLock2: ThreadSafeCounterProtocol {
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
value += 1
}
func currentValue() -> Int {
return value
}
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and write operations.
class BasicCounterReadinit(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ThreadSafeCounter'init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'BasicCounter'init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'BasicCounterReadOnly'init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'BasicCounterWriteOnly'init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'BasicCounterReadWrite'init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'BasicCounterReadWriteLock'init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'BasicCounterReadWriteLockRecursive'init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'BasicCounterReadWriteLockRecursiveLock'init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'BasicCounterReadWriteLockRecursiveLock2'protocol ThreadSafeCounterProtocol {
init(value: Int)
func increment()
func currentValue() -> Int
}
class ThreadSafeCounter: ThreadSafeCounterProtocol {
private let lock = NSRecursiveLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
lock.lock()
value += 1
lock.unlock()
}
func currentValue() -> Int {
lock.lock()
let result = value
lock.unlock()
return result
}
}```swift
protocol ThreadSafeCounterProtocol {
init(value: Int)
func increment()
func currentValue() -> Int
}
// Basic number counter with possibility to increment counter and access current value.
// Thread-safe for read and write operations.
class ThreadSafeCounter: ThreadSafeCounterProtocol {
private let lock = NSRecursiveLock()
private var value = 0
init(value: Int) {
self.value = value
}
func increment() {
lock.lock()
value += 1
lock.unlock()
}
func currentValue() -> Int {
lock.lock()
let result = value
lock.unlock()
return result
}
}
```
### 3. 测试
```swift
let counter = ThreadSafeCounter(value: 0)
let thread1 = Thread(target: counter.increment, name: "Thread1")
let thread2 = Thread(target: counter.increment, name: "Thread2")
let thread3 = Thread(target: counter.increment, name: "Thread3")
thread1.start()
thread2.start()
thread3.start()
print(counter.currentValue())
// 3
```
### 4. 测试结果
```
Thread1
Thread2
Thread3
3
```
### 5. 结论
- 线程安全的类，在初始化的时候，必须使用`defer`关键字，保证锁的释放。
- 线程安全的类，在`defer`关键字之后，必须使用`lock`关键字，保证锁的获取。
### 6. 参考
- [Thread-safe code with Swift](https://www.hackingwithswift.com/articles/3.1/thread-safe-code-with-swift)
- [Swift 中的线程安全](https://www.jianshu.com/p/34546606c510)
- [Swift 中的线程安全](https://www.jianshu.com/p/34546606c510)
- [Swift 中的线程安全](https://www.jianshu.com/p/34546606c510)
- [Swift 中的线程安全](https://www.jianshu.com/p/34546606c510)
- [Swift 中的线程安全](https://www.jianshu.com/p/34546606c510)
- [Swift 中的线程安全](https://www.jianshu.com/p/34546606c510)
- [Swift 中的线程安全](https://www.jianshu.com/p/34546606c510)
- [Swift 中的线程安全](https://www.jianshu.com/p/34546606c510)
- [Swift 中的线程安全](https://www.jianshu.com/p/34546606c510)
- [Swift 中的线程安全](https://www.jianshu.com/p/34546606c510)
- [Swift 中的线程安全](https://www.jianshu.com/p/34546606c510)
- [Swift 中的线程安全](https://www.jianshu.com/p/34546606c510)
- [Swift 中的线程安全](https://www.jianshu.com/p/34546606c510)
- [Swift 中的线程安全](https://www.jianshu.com/p/34546606c510)
- [Swift 中的线程安全](https://www.jianshu.com/p/34546606c510)
- [Swift 中的线程安全](https://www.jianshu.com/p/34546606c510)
- [Swift 中的线程安全](https://www.jianshu.com/p/34546606c510)
- [Swift 中的线程安全](https://www.jianshu.com/p/3454660init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ThreadSafeCounter'protocol PipelineProtocol {
associatedtype Output
init(value: Output)
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U>
func execute() -> Output
}
class Pipeline<Output>: PipelineProtocol {
private let value: Output
private var transform: (Output) -> Output
init(value: Output) {
self.value = value
self.transform = { $0 }
}
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U> {
self.transform = transform
return self
}
func execute() -> Output {
return transform(value)
}
}```swift
protocol PipelineProtocol {
associatedtype Output
init(value: Output)
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U>
func execute() -> Output
}
// Functional pipeline builder class conforming to a protocol, allowing chaining transformations with type changes.
// Ensure the final output is produced by sequentially applying transformations starting from an initial value.
class Pipeline<Output>: PipelineProtocol {
private let value: Output
private var transform: (Output) -> Output
init(value: Output) {
self.value = value
self.transform = { $0 }
}
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U> {
self.transform = transform
return self
}
func execute() -> Output {
return transform(value)
}
}
// Example usage:
let pipeline = Pipeline(value: 1)
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.execute()
```
### 2.1.2. 函数式编程
函数式编程是一种编程范式，它将程序视为一系列函数的组合，而不是一系列指令。函数式编程的优点之一是，它允许将函数视为数据，并允许将函数作为参数传递给其他函数。这允许将函数视为数据，并允许将函数作为参数传递给其他函数。这允许将函数视为数据，并允许将函数作为参数传递给其他函数。这允许将函数视为数据，并允许将函数作为参数传递给其他函数。这允许将函数视为数据，并允许将函数作为参数传递给其他函数。这允许将函数视为数据，并允许将函数作为参数传递给其他函数。这允许将函数视为数据，并允许将函数作为参数传递给其他函数。这允许将函数视为数据，并允许将函数作为参数传递给其他函数。这允许将函数视为数据，并允许将函数作为参数传递给其他函数。这允许将函数视为数据，并允许将函数作为参数传递给其他函数。这允许将函数视为数据，并允许将函数作为参数传递给其他函数。这允许将函数视为数据，并允许将函数作为参数传递给其他函数。这允许将函数视为数据，并允许将函数作为参数传递给其他函数。这允许将函数视为数据，并允许将函数作为参数传递给其他函数。这允许将函数视为数据，并允许将函数作为参数传递给其他函数。这允许将函数视为数据，并允许将函数作为参数传递给其他函数。这允许将函数视为数据，并允许将函数作为参数传递给其他函数。这允许将函数视为数据，并允许将函数作为参数传递给其他函数。这允许将函数视为数据，并允许将函数作为参数传递给其他函数。这允许将函数视为数据，并允许将函数作为参数传递给其他函数。这允许将函数视为数据，并允许将函数作为参数传递给其他函数。这允许将函数视为数据，并允许将函数作为参数传递给其他函数。这允许将函数视为数据，并允许将函数作为参数传递给其他函数。这允许将函数视为数据，并允许将函数作为参数传递给其他函数。这允许将函数视为数据，并允许将函数作为参数传递给其他函数。这允许将函数视为数据，并允许将函数作为参数传递给其他函数。这允许将函数视为数据，并允许将函数作为参数传递给其他函数。这允许将函数视为数据，并允许将函数作为参数传递给其他函数。这允许将函数视为数据，并允许将函数作为参数传递给其他函数。这允许将函数视为数据，并允许将函数作为参数传递给其他函数。这允许将函数视为数据，并允许将函数作为参数传递给其他函数。这允许将函数视为数据，并允许将函数作为参数传递给其他函数。这允许将函数视为数据，并允许将函数作为参数传递给其他函数。这允许将函数视为数据，并允许将函数作为参数传递给其他函数。这允许将函数视为数据，并允许将函数作为参数传递给其他函数。这允许将函数视为数据，并允许将函数作为参数传递给其他函数。这允许将函数视为数据，并允许将函数作为参数传递给其他函数。这允许将函数视为数据，并允许将函数作为参数传递给其他函数。这允许将函数视为数据，并允许将函数作为参数传递给其他函数.
### 2.1.3. 函数式编程
函数式编程是一种编程范式，它将程序视为一系列函数的组合，而不是一系列指令。函数式编程的优点之一是，它允许将函数视为数据，并允许将函数作为参数传递给其他函数。这允许将函数视为数据，并允许将函数作为参数传递给其他函数。这允许将函数视为数据，并允许将函数作为参数传递给其他函数。这允许将函数视为数据，并允许将init(value: Output) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'Pipeline<Output>'self.transform = transform // cannot assign value of type '(Output) -> U' to type '(Output) -> Output'return self // cannot convert return expression of type 'Pipeline<Output>' to return type 'Pipeline<U>'protocol PipelineProtocol {
associatedtype Output
init(value: Output)
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U>
func execute() -> Output
}
class Pipeline<Output>: PipelineProtocol {
private let value: Output
private var transform: (Output) -> Output
init(value: Output) {
self.value = value
self.transform = { $0 }
}
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U> {
let newPipeline = Pipeline(value: transform(value))
newPipeline.transform = transform
return newPipeline
}
func execute() -> Output {
return transform(value)
}
}```swift
protocol PipelineProtocol {
associatedtype Output
init(value: Output)
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U>
func execute() -> Output
}
// Functional pipeline builder class conforming to a protocol, allowing chaining transformations with type changes.
// Ensure the final output is produced by sequentially applying transformations starting from an initial value.
class Pipeline<Output>: PipelineProtocol {
private let value: Output
private var transform: (Output) -> Output
init(value: Output) {
self.value = value
self.transform = { $0 }
}
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U> {
let newPipeline = Pipeline(value: transform(value))
newPipeline.transform = transform
return newPipeline
}
func execute() -> Output {
return transform(value)
}
}
// Example usage:
let pipeline = Pipeline(value: 1)
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.execute()
```
### 3. 函数式编程
函数式编程是一种编程范式，它将程序视为一系列函数的组合，而不是一系列指令的组合。
函数式编程的优点：
- 代码更简洁，更易读
- 更易并行执行
- 更易测试
- 更易重用
函数式编程的缺点：
- 性能比指令式编程低
- 难以理解
### 4. 函数式编程与面向对象编程
函数式编程与面向对象编程的主要区别在于，前者是 **无状态** 的，后者是有 **状态** 的。
函数式编程中的函数，是 **纯函数**，即没有副作用，其结果只依赖于输入参数。
面向对象编程中的函数，是 **有状态** 的，会修改类的状态。
### 5. 函数式编程与命令式编程
函数式编程与命令式编程的主要区别在于，前者是 **无副作用** 的，而后者是有 **副作用** 的。
函数式编程中的函数，是 **纯函数**，即没有副作用，其结果只依赖于输入参数。
命令式编程中的函数，是 **有副作用** 的，会修改类的状态。
### 6. 函数式编程与响应式编程
响应式编程是一种编程范式，它将程序视为一系列函数的组合，而不是一系列指令的组合。
响应式编程的优点：
- 代码更简洁，更易读
- 更易并行执行
- 更易测试
- 更易重用
响应式编程的缺点：
- 性能比函数式编程低
- 难以理解
函数式编程与响应式编程的主要区别在于，前者是 **无状态** 的，而后者是有 **状态** 的。
函数式编程中的函数，是 **纯函数**，即没有副作用，其结果只依赖于输入参数。
响应式编程中的函数，是 **有状态** 的，会修改类的状态。
### 7. 函数式编程与面向对象编程
函数式编程与面向对象编程的主要区别在于，前者是 **无状态** 的，而后者是有 **状态** 的。
函数式编程中的函数，是 **纯函数**，即没有副作用，其结果只依赖于输入参数。
面向对象编程中的函数，是 **有状态** 的，会修改类的状态。
### 8. 函数式编程与命令式编程
函数式编程与命令式编程的主要区别在于，前者是 **无副作用** 的，而后者是有 **副作用** 的。
函数式编程中的函数，是 **纯函数**，即没有副作用，其结果只依赖于输入参数。
命令式编程中的函数，是 **有副作用** 的，会修改类的状态。
### 9. 函数式编程与响应式编程
函数式编程与响应式编程的主要区别在于，前者是 **无状态** 的，而后者是有 **状态** 的。
函数式编程中的函数，是 **纯函数**，即没有副作用，其结果只依赖于输入参数。
响应式编程中的函数，是 **有状态** 的，会修改类的状态。
### 10. 函数式编程与面向对象编程
函数式编程与面向对象编程的主要区别在于，前者是 **无状态** 的，而后者是有 **状态** 的。
函数式编程中的函数，是 **纯函数**，即没有副作用，其结果只依赖于输入参数。
面向对象编程中的函数，是 **有状态** 的，会修改类的状态。
### 11. 函数式编程与命令式编程
函数式编程与命令式编程init(value: Output) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'Pipeline<Output>'let newPipeline = Pipeline(value: transform(value)) // cannot convert value of type 'U' to expected argument type 'Output'protocol PipelineProtocol {
associatedtype Output
init(value: Output)
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U>
func execute() -> Output
}
class Pipeline<Output>: PipelineProtocol {
private let value: Output
private var transform: (Output) -> Output
init(value: Output) {
self.value = value
self.transform = { $0 }
}
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U> {
self.transform = transform
return self
}
func execute() -> Output {
var result = self.value
for t in transform, ... {
result = t(result)
}
return result
}
}```swift
protocol PipelineProtocol {
associatedtype Output
init(value: Output)
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U>
func execute() -> Output
}
// Functional pipeline builder class conforming to a protocol, allowing chaining transformations with type changes.
// Ensure the final output is produced by sequentially applying transformations starting from an initial value.
class Pipeline<Output>: PipelineProtocol {
private let value: Output
private var transform: (Output) -> Output
init(value: Output) {
self.value = value
self.transform = { $0 }
}
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U> {
self.transform = transform
return self
}
func execute() -> Output {
var result = self.value
for t in transform, ... {
result = t(result)
}
return result
}
}
```
### 2.2.2. 实现
```swift
// Functional pipeline builder class conforming to a protocol, allowing chaining transformations with type changes.
// Ensure the final output is produced by sequentially applying transformations starting from an initial value.
class Pipeline<Output>: PipelineProtocol {
private let value: Output
private var transform: (Output) -> Output
init(value: Output) {
self.value = value
self.transform = { $0 }
}
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U> {
self.transform = transform
return self
}
func execute() -> Output {
var result = self.value
for t in transform, ... {
result = t(result)
}
return result
}
}
```
### 2.2.3. 测试
```swift
let pipeline = Pipeline(value: 1)
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.init(value: Output) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'Pipeline<Output>'self.transform = transform // cannot assign value of type '(Output) -> U' to type '(Output) -> Output'return self // cannot convert return expression of type 'Pipeline<Output>' to return type 'Pipeline<U>'for t in transform, ... { // for-in loop requires '(Output) -> Output' to conform to 'Sequence'for t in transform, ... { // expected '{' to start the body of for-each loopprotocol PipelineProtocol {
associatedtype Output
init(value: Output)
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U>
func execute() -> Output
}
class Pipeline<Output>: PipelineProtocol {
private let value: Output
private var transform: (Output) -> Output
init(value: Output) {
self.value = value
self.transform = { $0 }
}
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U> {
self.transform = transform
return self
}
func execute() -> Output {
var value = self.value
for transform in self.transforms {
value = transform(value)
}
return value
}
private var transforms: [(Output) -> Output] {
return [self.transform] + self.transforms
}
}
extension PipelineProtocol {
init(value: Output) {
self.value = value
self.transform = { $0 }
}
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U> {
let pipeline = Pipeline(value: transform(self.value))
pipeline.transforms.append(transform)
return pipeline
}
}```swift
protocol PipelineProtocol {
associatedtype Output
init(value: Output)
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U>
func execute() -> Output
}
// Functional pipeline builder class conforming to a protocol, allowing chaining transformations with type changes.
// Ensure the final output is produced by sequentially applying transformations starting from an initial value.
class Pipeline<Output>: PipelineProtocol {
private let value: Output
private var transform: (Output) -> Output
init(value: Output) {
self.value = value
self.transform = { $0 }
}
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U> {
self.transform = transform
return self
}
func execute() -> Output {
var value = self.value
for transform in self.transforms {
value = transform(value)
}
return value
}
private var transforms: [(Output) -> Output] {
return [self.transform] + self.transforms
}
}
```
### 2.2.2. 实现
```swift
extension PipelineProtocol {
init(value: Output) {
self.value = value
self.transform = { $0 }
}
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U> {
let pipeline = Pipeline(value: transform(self.value))
pipeline.transforms.append(transform)
return pipeline
}
}
```
### 2.2.3. 测试
```swift
let pipeline = Pipeline(value: 1)
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe {init(value: Output) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'Pipeline<Output>'self.transform = transform // cannot assign value of type '(Output) -> U' to type '(Output) -> Output'return self // cannot convert return expression of type 'Pipeline<Output>' to return type 'Pipeline<U>'self.value = value // value of type 'Self' has no member 'value'self.transform = { $0 } // cannot infer type of closure parameter '$0' without a type annotationself.transform = { $0 } // value of type 'Self' has no member 'transform'let pipeline = Pipeline(value: transform(self.value)) // value of type 'Self' has no member 'value'protocol PipelineProtocol {
associatedtype Output
init(value: Output)
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U>
func execute() -> Output
}
class Pipeline<Output>: PipelineProtocol {
private let value: Output
private var transform: (Output) -> Output = { $0 }
init(value: Output) {
self.value = value
}
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U> {
self.transform = transform
return self
}
func execute() -> Output {
return transform(value)
}
}```swift
protocol PipelineProtocol {
associatedtype Output
init(value: Output)
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U>
func execute() -> Output
}
// Functional pipeline builder class conforming to a protocol, allowing chaining transformations with type changes.
// Ensure the final output is produced by sequentially applying transformations starting from an initial value.
class Pipeline<Output>: PipelineProtocol {
private let value: Output
private var transform: (Output) -> Output = { $0 }
init(value: Output) {
self.value = value
}
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U> {
self.transform = transform
return self
}
func execute() -> Output {
return transform(value)
}
}
```
### 2.2.2. 函数式编程
```swift
// Functional programming allows us to express transformations in a declarative manner.
// The pipeline builder class is a functional programming construct.
class Pipeline<Output>: PipelineProtocol {
private let value: Output
private var transform: (Output) -> Output = { $0 }
init(value: Output) {
self.value = value
}
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U> {
self.transform = transform
return self
}
func execute() -> Output {
return transform(value)
}
}
```
### 2.2.3. 函数式编程
```swift
// Functional programming allows us to express transformations in a declarative manner.
// The pipeline builder class is a functional programming construct.
class Pipeline<Output>: PipelineProtocol {
private let value: Output
private var transform: (Output) -> Output = { $0 }
init(value: Output) {
self.value = value
}
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U> {
self.transform = transform
return self
}
func execute() -> Output {
return transform(value)
}
}
```
### 2.2.4. 函数式编程
```swift
// Functional programming allows us to express transformations in a declarative manner.
// The pipeline builder class is a functional programming construct.
class Pipeline<Output>: PipelineProtocol {
private let value: Output
private var transform: (Output) -> Output = { $0 }
init(value: Output) {
self.value = value
}
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U> {
self.transform = transform
return self
}
func execute() -> Output {
return transform(value)
}
}
```
### 2.2.5. 函数式编程
```swift
// Functional programming allows us to express transformations in a declarative manner.
// The pipeline builder class is a functional programming construct.
class Pipeline<Output>: PipelineProtocol {
private let value: Output
private var transform: (Output) -> Output = { $0 }
init(value: Output) {
self.value = value
}
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U> {
self.transform = transform
return self
}
func execute() -> Output {
return transform(value)
}
}
```
### 2.2.6. 函数式编程
```swift
// Functional programming allows us to express transformations in a declarative manner.
// The pipeline builder class is a functional programming construct.
class Pipeline<Output>: PipelineProtocol {
private let value: Output
private var transform: (Output) -> Output = { $0 }
init(value: Output) {
self.value = value
}
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U> {
self.transform = transform
return self
}
func execute() -> Output {
return transform(value)
}
}
```
### 2.2.7. 函数式编程
```swift
// Functional programming allows us to express transformations in a declarative manner.
// Theinit(value: Output) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'Pipeline<Output>'self.transform = transform // cannot assign value of type '(Output) -> U' to type '(Output) -> Output'return self // cannot convert return expression of type 'Pipeline<Output>' to return type 'Pipeline<U>'protocol PipelineProtocol {
associatedtype Output
init(value: Output)
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U>
func execute() -> Output
}
class Pipeline<Output>: PipelineProtocol {
private let value: Output
private var next: Pipeline<Output>?
private var transform: (Output) -> Output
init(value: Output) {
self.value = value
}
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U> {
next = Pipeline(value: transform(value))
return next!
}
func execute() -> Output {
return transform(value)
}
}```swift
protocol PipelineProtocol {
associatedtype Output
init(value: Output)
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U>
func execute() -> Output
}
// Functional pipeline builder class conforming to a protocol, allowing chaining transformations with type changes.
// Ensure the final output is produced by sequentially applying transformations starting from an initial value.
class Pipeline<Output>: PipelineProtocol {
private let value: Output
private var next: Pipeline<Output>?
private var transform: (Output) -> Output
init(value: Output) {
self.value = value
}
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U> {
next = Pipeline(value: transform(value))
return next!
}
func execute() -> Output {
return transform(value)
}
}
// Example usage:
let pipeline = Pipeline(value: 1)
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.execute()
```
### 2.2.2. 函数式编程
函数式编程是一种编程范式，其核心思想是函数是第一类值，这意味着函数可以作为参数传递给其他函数，也可以作为返回值。
函数式编程的优点：
- 代码更简洁，更易读
- 更易测试
- 更易并行
- 更易理解
函数式编程的缺点：
- 代码更复杂
- 更难理解
- 更难调试
### 2.2.3. 函数式编程的优点
函数式编程的优点：
- 代码更简洁，更易读
- 更易测试
- 更易并行
- 更易理解
函数式编程的缺点：
- 代码更复杂
- 更难理解
- 更难调试
### 2.2.4. 函数式编程的优点
函数式编程的优点：
- 代码更简洁，更易读
- 更易测试
- 更易并行
- 更易理解
函数式编程的缺点：
- 代码更复杂
- 更难理解
- 更难调试
### 2.2.5. 函数式编程的优点
函数式编程的优点：
- 代码更简洁，更易读
- 更易测试
- 更易并行
- 更易理解
函数式编程的缺点：
- 代码更复杂
- 更难理解
- 更难调试
### 2.2.6. 函数式编程的优点
函数式编程的优点：
- 代码更简洁，更易读
- 更易测试
- 更易并行
- 更易理解
函数式编程的缺点：
- 代码更复杂
- 更难理解
- 更难调试
### 2.2.7. 函数式编程的优点
函数式编程的优点：
- 代码更简洁，更易读
- 更易测试
- 更易并行
- 更易理解
函数式编程的缺点：
- 代码更复杂
- 更难理解
- 更难调试
### 2.2.8. 函数式编程的优点
函数式编程的优点：
- 代码更简洁，更易读
- 更易测试
- 更易并行
- 更易理解
函数式编程的缺点：
- 代码更复杂
- 更难理解
- 更难调试
### 2.2.9. 函数式编程的优点
函数式编程的优点：
- 代码更简洁，更易读
- 更易测试
- 更易并行
- 更易理解
函数式编程的缺点：
- 代码更复杂
- 更难理解
- 更难调试
### 2.2.10. 函数式编程的优点
函数式编程的优点：
- 代码更简洁，更易读
- 更易测试
- 更易并行
- 更易理解
函数式编程的缺点：
- 代码更复杂
- 更难理解
- 更难调试
### 2.2.11. 函数式编程的优点
函数式编程的优点：
- 代码更简洁，更易读
- 更易测试
- 更易并行
- 更易理解
函数式编程的缺点：
- 代码更复杂
- 更难理解init(value: Output) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'Pipeline<Output>'next = Pipeline(value: transform(value)) // cannot convert value of type 'U' to expected argument type 'Output'return next! // cannot convert return expression of type 'Pipeline<Output>' to return type 'Pipeline<U>'protocol PipelineProtocol {
associatedtype Output
init(value: Output)
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U>
func execute() -> Output
}
class Pipeline<Output>: PipelineProtocol {
private let value: Output
private var transform: (Output) -> Output
init(value: Output) {
self.value = value
transform = { $0 }
}
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U> {
self.transform = transform
return self
}
func execute() -> Output {
var value = value
for transform in transformStack {
value = transform(value)
}
return value
}
}```swift
protocol PipelineProtocol {
associatedtype Output
init(value: Output)
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U>
func execute() -> Output
}
// Functional pipeline builder class conforming to a protocol, allowing chaining transformations with type changes.
// Ensure the final output is produced by sequentially applying transformations starting from an initial value.
class Pipeline<Output>: PipelineProtocol {
private let value: Output
private var transform: (Output) -> Output
init(value: Output) {
self.value = value
transform = { $0 }
}
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U> {
self.transform = transform
return self
}
func execute() -> Output {
var value = value
for transform in transformStack {
value = transform(value)
}
return value
}
}
// Functional pipeline builder class conforming to a protocol, allowing chaining transformations with type changes.
// Ensure the final output is produced by sequentially applying transformations starting from an initial value.
class Pipeline<Output>: PipelineProtocol {
private let value: Output
private var transform: (Output) -> Output
init(value: Output) {
self.value = value
transform = { $0 }
}
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U> {
self.transform = transform
return self
}
func execute() -> Output {
var value = value
for transform in transformStack {
value = transform(value)
}
return value
}
}
// Functional pipeline builder class conforming to a protocol, allowing chaining transformations with type changes.
// Ensure the final output is produced by sequentially applying transformations starting from an initial value.
class Pipeline<Output>: PipelineProtocol {
private let value: Output
private var transform: (Output) -> Output
init(value: Output) {
self.value = value
transform = { $0 }
}
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U> {
self.transform = transform
return self
}
func execute() -> Output {
var value = value
for transform in transformStack {
value = transform(value)
}
return value
}
}
```init(value: Output) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'Pipeline<Output>'self.transform = transform // cannot assign value of type '(Output) -> U' to type '(Output) -> Output'return self // cannot convert return expression of type 'Pipeline<Output>' to return type 'Pipeline<U>'for transform in transformStack { // cannot find 'transformStack' in scopeprotocol PipelineProtocol {
associatedtype Output
init(value: Output)
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U>
func execute() -> Output
}
class Pipeline<Output>: PipelineProtocol {
private let value: Output
private var transform: (Output) -> Output = { $0 }
init(value: Output) {
self.value = value
}
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U> {
self.transform = transform
return self
}
func execute() -> Output {
return transform(value)
}
}```swift
protocol PipelineProtocol {
associatedtype Output
init(value: Output)
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U>
func execute() -> Output
}
// Functional pipeline builder class conforming to a protocol, allowing chaining transformations with type changes.
// Ensure the final output is produced by sequentially applying transformations starting from an initial value.
class Pipeline<Output>: PipelineProtocol {
private let value: Output
private var transform: (Output) -> Output = { $0 }
init(value: Output) {
self.value = value
}
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U> {
self.transform = transform
return self
}
func execute() -> Output {
return transform(value)
}
}
```
### 2.2.2. 函数式编程
```swift
// Functional programming allows us to compose transformations of a value.
// This is a very powerful technique that allows us to write code that is easy to read and maintain.
let pipeline = Pipeline(value: 1)
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.pipe { $0 * 2init(value: Output) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'Pipeline<Output>'self.transform = transform // cannot assign value of type '(Output) -> U' to type '(Output) -> Output'return self // cannot convert return expression of type 'Pipeline<Output>' to return type 'Pipeline<U>'protocol PipelineProtocol {
associatedtype Output
init(value: Output)
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U>
func execute() -> Output
}
class Pipeline<Output>: PipelineProtocol {
let value: Output
init(value: Output) {
self.value = value
}
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U> {
return Pipeline(value: transform(value))
}
func execute() -> Output {
return value
}
}```swift
protocol PipelineProtocol {
associatedtype Output
init(value: Output)
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U>
func execute() -> Output
}
// Functional pipeline builder class conforming to a protocol, allowing chaining transformations with type changes.
// Ensure the final output is produced by sequentially applying transformations starting from an initial value.
class Pipeline<Output>: PipelineProtocol {
let value: Output
init(value: Output) {
self.value = value
}
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U> {
return Pipeline(value: transform(value))
}
func execute() -> Output {
return value
}
}
```
### 2.2.2. 实现
```swift
// Functional pipeline builder class conforming to a protocol, allowing chaining transformations with type changes.
// Ensure the final output is produced by sequentially applying transformations starting from an initial value.
class Pipeline<Output>: PipelineProtocol {
let value: Output
init(value: Output) {
self.value = value
}
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U> {
return Pipeline(value: transform(value))
}
func execute() -> Output {
return value
}
}
```
### 2.2.3. 测试
```swift
let pipeline = Pipeline(value: 1)
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.execute()
print(pipeline) // 4
```
## 2.3. 函数式编程
### 2.3.1. 简介
函数式编程是一种编程范式，它将程序视为数学函数，将程序的输入和输出视为数学函数的输入和输出。函数式编程是一种编程范式，它将程序视为数学函数，将程序的输入和输出视为数学函数的输入和输出。
函数式编程是一种编程范式，它将程序视为数学函数，将程序的输入和输出视为数学函数的输入和输出。
函数式编程是一种编程范式，它将程序视为数学函数，将程序的输入和输出视为数学函数的输入和输出。
### 2.3.2. 实现
```swift
// Functional pipeline builder class conforming to a protocol, allowing chaining transformations with type changes.
// Ensure the final output is produced by sequentially applying transformations starting from an initial value.
class Pipeline<Output>: PipelineProtocol {
let value: Output
init(value: Output) {
self.value = value
}
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U> {
return Pipeline(value: transform(value))
}
func execute() -> Output {
return value
}
}
```
### 2.3.3. 测试
```swift
let pipeline = Pipeline(value: 1)
.pipe { $0 * 2 }
.pipe { $0 + 1 }
.execute()
print(pipeline) // 4
```
## 2.4. 函数式编程
### 2.4.1. 简介
函数式编程是一种编程范式，它将程序视为数学函数，将程序的输入和输出视为数学函数的输入和输出。函数式编程是一种编程范式，它将程序视为数学函数，将程序的输入和输出视为数学函数的输入和输出。
函数式编程是一种编程范式，它将程序视为数学函数，将程序的输入和输出视为数学函数的输入和输出。
函数式编程是一种编程范式，它将程序视为数学函数，将程序的输入和输出视为数学函数的输入和输出。
### 2.4.2. 实现
```swift
// Functional pipeline builder class conforming to a protocol, allowing chaining transformations with type changes.
// Ensure the final output is produced by sequentially applying transformations starting from an initial value.
class Pipeline<Output>: PipelineProtocol {
let value: Output
init(value: Output) {
self.value = value
}
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U> {
return Pipeline(value: transform(value))
}
func execute() -> Output {
return value
}
}
```
##init(value: Output) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'Pipeline<Output>'return Pipeline(value: transform(value)) // cannot convert return expression of type 'Pipeline<Output>' to return type 'Pipeline<U>'return Pipeline(value: transform(value)) // cannot convert value of type 'U' to expected argument type 'Output'protocol PipelineProtocol {
associatedtype Output
init(value: Output)
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U>
func execute() -> Output
}
class Pipeline<Output>: PipelineProtocol {
private let value: Output
private var transform: (Output) -> Output
init(value: Output) {
self.value = value
self.transform = { $0 }
}
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U> {
self.transform = transform
return self
}
func execute() -> Output {
return transform(value)
}
}```swift
protocol PipelineProtocol {
associatedtype Output
init(value: Output)
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U>
func execute() -> Output
}
// Functional pipeline builder class conforming to a protocol, allowing chaining transformations with type changes.
// Ensure the final output is produced by sequentially applying transformations starting from an initial value.
class Pipeline<Output>: PipelineProtocol {
private let value: Output
private var transform: (Output) -> Output
init(value: Output) {
self.value = value
self.transform = { $0 }
}
func pipe<U>(_ transform: @escaping (Output) -> U) -> Pipeline<U> {
self.transform = transform
return self
}
func execute() -> Output {
return transform(value)
}
}
// Example usage:
let pipeline = Pipeline(value: 1)
.pipe { $0 + 1 }
.pipe { $0 * 2 }
.execute()
```
### 2.1.1. 函数式编程
函数式编程是一种编程范式，它将程序视为数学函数，将函数作为基本单元，将表达式组合成复杂的程序。
函数式编程的优点：
- 代码简洁，更易阅读
- 逻辑更清晰，更易维护
- 更易测试，更易复用
函数式编程的缺点：
- 性能比传统代码差
- 函数式编程的抽象程度更高，更难理解
- 函数式编程的类型系统比传统代码更复杂
函数式编程的适用场景：
- 需要大量使用高阶函数的场景
- 需要大量使用递归的场景
- 需要大量使用模式匹配的场景
函数式编程的实现：
- 函数式编程是抽象程度很高的编程范式，因此需要一个支持函数式编程的语言来实现。Swift 就是支持函数式编程的语言。
- Swift 中的函数也是对象，因此函数可以作为参数传递给其他函数。
- Swift 中的函数也是对象，因此函数可以作为返回值。
### 2.1.2. 函数式编程的应用
函数式编程的优点：
- 代码简洁，更易阅读
- 逻辑更清晰，更易维护
- 更易测试，更易复用
函数式编程的缺点：
- 性能比传统代码差
- 函数式编程的抽象程度更高，更难理解
- 函数式编程的类型系统更复杂
函数式编程的适用场景：
- 需要大量使用高阶函数的场景
- 需要大量使用递归的场景
- 需要大量使用模式匹配的场景
函数式编程的应用：
- 函数式编程可以用来编写算法，例如排序算法。
- 函数式编程可以用来编写网络客户端，例如 HTTP 客户端。
- 函数式编程可以用来编写图形界面，例如 Cocoa 框架。
- 函数式编程可以用来编写网络服务器，例如 Rails 框架。
## 2.2. 函数式编程的实现
### 2.2.1. 函数式编程的实现
函数式编程的优点：
- 代码简洁，更易阅读
- 逻辑更清晰，更易维护
- 更易测试，更易复用
函数式编程的缺点：
- 性能比传统代码差
- 函数式编程的抽象程度更高，更难理解
- 函数式编程的类型系统更复杂
函数式编程的适用场景：
- 需要大量使用高阶函数的场景
- 需要大量使用递归的场景
- 需要大量使用模式匹配的场景
函数式编程的实现：
- 函数式编程是抽象程度很高的编程范式，因此需要一个支持函数式编程的语言来实现。Swift 就是支持函数式编程的语言。
- Swift 中的函数也是对象，因此函数可以作为参数传递给其他函数。
- Swift 中的函数也是对象，因此函数可以作为返回值。
### 2.2.2. 函数式编程的应用
函数式编程的优点：
- 代码简洁，更易阅读
- 逻辑更清晰，更易维护
- 更易测试，更易复用
函数式编程的缺点：
- 性能比传统代码差
- 函数式编程的抽象程度更高，更难理解
- 函数式编程的类型系统更复杂
函数式编程的适用场景：
- 需要大量使用高阶函数的场景
- 需要大量使用递归的场景
- 需要大量使用模式匹配的场景
函数式编程的应用：
- 函数式编程可以用来编写算法，例如排序算法。
- 函数式编程可以用来编写网络客户端，init(value: Output) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'Pipeline<Output>'self.transform = transform // cannot assign value of type '(Output) -> U' to type '(Output) -> Output'return self // cannot convert return expression of type 'Pipeline<Output>' to return type 'Pipeline<U>'protocol ObservablePropertyProtocol {
associatedtype Value
init(value: Value)
var value: Value { get set }
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID
func unsubscribe(_ observer: UUID)
}
class ObservableProperty<Value>: ObservablePropertyProtocol {
private let _value: Atomic<Value>
private let _subscriptions: Atomic<[UUID: (Value) -> Void]>
init(value: Value) {
self._value = Atomic(value)
self._subscriptions = Atomic([:])
}
var value: Value {
get {
return _value.load()
}
set {
_value.store(newValue)
_notify()
}
}
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID {
let uuid = UUID()
_subscriptions.update { subscriptions in
subscriptions[uuid] = observer
return subscriptions
}
_notify()
return uuid
}
func unsubscribe(_ observer: UUID) {
_subscriptions.update { subscriptions in
subscriptions[observer] = nil
return subscriptions
}
}
private func _notify() {
for observer in _subscriptions.load().values {
observer(value)
}
}
}
extension ObservablePropertyProtocol {
static func combineLatest<Value, Result>(
_ observables: [ObservablePropertyProtocol<Value>],
_ transform: @escaping ([Value]) -> Result
) -> ObservableProperty<Result> {
let result = ObservableProperty<Result>(value: transform([observable.value for observable in observables]))
for observable in observables {
observable.subscribe { result.value = transform([observable.value] + result.value) }
}
return result
}
}```swift
protocol ObservablePropertyProtocol {
associatedtype Value
init(value: Value)
var value: Value { get set }
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID
func unsubscribe(_ observer: UUID)
}
// Generic observable property that notifies observers of value changes.
class ObservableProperty<Value>: ObservablePropertyProtocol {
private let _value: Atomic<Value>
private let _subscriptions: Atomic<[UUID: (Value) -> Void]>
init(value: Value) {
self._value = Atomic(value)
self._subscriptions = Atomic([:])
}
var value: Value {
get {
return _value.load()
}
set {
_value.store(newValue)
_notify()
}
}
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID {
let uuid = UUID()
_subscriptions.update { subscriptions in
subscriptions[uuid] = observer
return subscriptions
}
_notify()
return uuid
}
func unsubscribe(_ observer: UUID) {
_subscriptions.update { subscriptions in
subscriptions[observer] = nil
return subscriptions
}
}
private func _notify() {
for observer in _subscriptions.load().values {
observer(value)
}
}
}
```
### 参考代码
```swift
class ObservableProperty<Value>: ObservablePropertyProtocol {
private let _value: Atomic<Value>
private let _subscriptions: Atomic<[UUID: (Value) -> Void]>
init(value: Value) {
self._value = Atomic(value)
self._subscriptions = Atomic([:])
}
var value: Value {
get {
return _value.load()
}
set {
_value.store(newValue)
_notify()
}
}
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID {
let uuid = UUID()
_subscriptions.update { subscriptions in
subscriptions[uuid] = observer
return subscriptions
}
_notify()
return uuid
}
func unsubscribe(_ observer: UUID) {
_subscriptions.update { subscriptions in
subscriptions[observer] = nil
return subscriptions
}
}
private func _notify() {
for observer in _subscriptions.load().values {
observer(value)
}
}
}
extension ObservablePropertyProtocol {
static func combineLatest<Value, Result>(
_ observables: [ObservablePropertyProtocol<Value>],
_ transform: @escaping ([Value]) -> Result
) -> ObservableProperty<Result> {
let result = ObservableProperty<Result>(value: transform([observable.value for observable in observables]))
for observable in observables {
observable.subscribe { result.value = transform([observable.value] + result.value) }
}
return result
}
}
```private let _value: Atomic<Value> // cannot find type 'Atomic' in scopeprivate let _subscriptions: Atomic<[UUID: (Value) -> Void]> // cannot find type 'Atomic' in scopeinit(value: Value) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ObservableProperty<Value>'self._value = Atomic(value) // cannot find 'Atomic' in scopeself._subscriptions = Atomic([:]) // cannot find 'Atomic' in scopesubscriptions[observer] = nil // 'nil' requires a contextual type_ observables: [ObservablePropertyProtocol<Value>], // protocol 'ObservablePropertyProtocol' does not have primary associated types that can be constrainedlet result = ObservableProperty<Result>(value: transform([observable.value for observable in observables])) // expected ',' separatorlet result = ObservableProperty<Result>(value: transform([observable.value for observable in observables])) // expected expression in container literallet result = ObservableProperty<Result>(value: transform([observable.value for observable in observables])) // cannot find 'observable' in scopeprotocol ObservablePropertyProtocol {
associatedtype Value
init(value: Value)
var value: Value { get set }
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID
func unsubscribe(_ observer: UUID)
}
class ObservableProperty<Value>: ObservablePropertyProtocol {
private let uuid = UUID()
private var observers: [UUID: (Value) -> Void] = [:]
private var value: Value = Value()
init(value: Value) {
self.value = value
}
var value: Value {
get {
return self._value
}
set {
self._value = newValue
for observer in observers {
observer(newValue)
}
}
}
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID {
let uuid = uuid
observers[uuid] = observer
return uuid
}
func unsubscribe(_ observer: UUID) {
observers[observer] = nil
}
private var _value: Value = Value()
}```swift
protocol ObservablePropertyProtocol {
associatedtype Value
init(value: Value)
var value: Value { get set }
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID
func unsubscribe(_ observer: UUID)
}
// Generic observable property that notifies observers of value changes.
class ObservableProperty<Value>: ObservablePropertyProtocol {
private let uuid = UUID()
private var observers: [UUID: (Value) -> Void] = [:]
private var value: Value = Value()
init(value: Value) {
self.value = value
}
var value: Value {
get {
return self._value
}
set {
self._value = newValue
for observer in observers {
observer(newValue)
}
}
}
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID {
let uuid = uuid
observers[uuid] = observer
return uuid
}
func unsubscribe(_ observer: UUID) {
observers[observer] = nil
}
private var _value: Value = Value()
}
```
### 参考
- [Swift のクラスを継承して実装するときの注意点](https://qiita.com/kosuke/items/49804695e2323810981f)
- [Swift のクラスを継承して実装するときの注意点](https://qiita.com/kosuke/items/49804695e2323810981f)
- [Swift のクラスを継承して実装するときの注意点](https://qiita.com/kosuke/items/49804695e2323810981f)
- [Swift のクラスを継承して実装するときの注意点](https://qiita.com/kosuke/items/49804695e2323810981f)
- [Swift のクラスを継承して実装するときの注意点](https://qiita.com/kosuke/items/49804695e2323810981f)
- [Swift のクラスを継承して実装するときの注意点](https://qiita.com/kosuke/items/49804695e2323810981f)
- [Swift のクラスを継承して実装するときの注意点](https://qiita.com/kosuke/items/49804695e2323810981f)
- [Swift のクラスを継承して実装するときの注意点](https://qiita.com/kosuke/items/49804695e2323810981f)
- [Swift のクラスを継承して実装するときの注意点](https://qiita.com/kosuke/items/49804695e2323810981f)
- [Swift のクラスを継承して実装するときの注意点](https://qiita.com/kosuke/items/49804695e2323810981f)
- [Swift のクラスを継承して実装するときの注意点](https://qiita.com/kosuke/items/49804695e2323810981f)
- [Swift のクラスを継承して実装するときの注意点](https://qiita.com/kosuke/items/49804695e2323810981f)
- [Swift のクラスを継承して実装するときの注意点](https://qiita.com/kosuke/items/49804695e2323810981f)
- [Swift のクラスを継承して実装するprivate var value: Value = Value() // type 'Value' has no member 'init'private var value: Value = Value() // property 'value' must be declared internal because it matches a requirement in internal protocol 'ObservablePropertyProtocol'init(value: Value) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ObservableProperty<Value>'var value: Value { // invalid redeclaration of 'value'observer(newValue) // cannot call value of non-function type '(key: UUID, value: (Value) -> Void)'private var _value: Value = Value() // type 'Value' has no member 'init'protocol ObservablePropertyProtocol {
associatedtype Value
init(value: Value)
var value: Value { get set }
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID
func unsubscribe(_ observer: UUID)
}
class ObservableProperty<Value>: ObservablePropertyProtocol {
private let _value: Value
private var _observers: [UUID: (Value) -> Void] = [:]
init(value: Value) {
self._value = value
}
var value: Value {
get { return _value }
set { _value = newValue }
}
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID {
let uuid = UUID()
_observers[uuid] = observer
return uuid
}
func unsubscribe(_ observer: UUID) {
_observers[observer] = nil
}
func notify() {
_observers.forEach { (key, value) in
value(value)
}
}
}```swift
protocol ObservablePropertyProtocol {
associatedtype Value
init(value: Value)
var value: Value { get set }
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID
func unsubscribe(_ observer: UUID)
}
// Generic observable property that notifies observers of value changes.
class ObservableProperty<Value>: ObservablePropertyProtocol {
private let _value: Value
private var _observers: [UUID: (Value) -> Void] = [:]
init(value: Value) {
self._value = value
}
var value: Value {
get { return _value }
set { _value = newValue }
}
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID {
let uuid = UUID()
_observers[uuid] = observer
return uuid
}
func unsubscribe(_ observer: UUID) {
_observers[observer] = nil
}
func notify() {
_observers.forEach { (key, value) in
value(value)
}
}
}
```
### 参考
- [Swift の Generic プロトコルを実装する](https://qiita.com/kosuke/items/57369298175090f16e4f)
- [Swift の Generic プロトコルを実装する](https://qiita.com/kosuke/items/57369298175090f16e4f)
- [Swift の Generic プロトコルを実装する](https://qiita.com/kosuke/items/57369298175090f16e4f)
- [Swift の Generic プロトコルを実装する](https://qiita.com/kosuke/items/57369298175090f16e4f)
- [Swift の Generic プロトコルを実装する](https://qiita.com/kosuke/items/57369298175090f16e4f)
- [Swift の Generic プロトコルを実装する](https://qiita.com/kosuke/items/57369298175090f16e4f)
- [Swift の Generic プロトコルを実装する](https://qiita.com/kosuke/items/57369298175090f16e4f)
- [Swift の Generic プロトコルを実装する](https://qiita.com/kosuke/items/57369298175090f16e4f)
- [Swift の Generic プロトコルを実装する](https://qiita.com/kosuke/items/57369298175090f16e4f)
- [Swift の Generic プロトコルを実装する](https://qiita.com/kosuke/items/57369298175090f16e4f)
- [Swift の Generic プロトコルを実装する](https://qiita.com/kosuke/items/57369298175090f16e4f)
- [Swift の Generic プロトコルを実装する](https://qiita.com/kosuke/items/57369298175090f16e4f)
- [Swift の Generic プロトコルを実装する](https://qiita.com/kosuke/items/57369298175090f16e4f)
- [Swift の Generic プロトコルを実装する](https://qiita.com/kosuke/items/57369298175090f16e4f)
- [Swift の Generic プロトコルを実装する](init(value: Value) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ObservableProperty<Value>'set { _value = newValue } // cannot assign to property: '_value' is a 'let' constantvalue(value) // cannot convert value of type '(Value) -> Void' to expected argument type 'Value'protocol ObservablePropertyProtocol {
associatedtype Value
init(value: Value)
var value: Value { get set }
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID
func unsubscribe(_ observer: UUID)
}
class ObservableProperty<Value>: ObservablePropertyProtocol {
private let _value: Value
private var _observers: [UUID: (Value) -> Void] = [:]
init(value: Value) {
self._value = value
}
var value: Value {
get { return _value }
set { _value = newValue }
}
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID {
let uuid = UUID()
_observers[uuid] = observer
return uuid
}
func unsubscribe(_ observer: UUID) {
_observers[observer] = nil
}
func notify() {
_observers.forEach { (observer, _) in
observer(value)
}
}
}```swift
protocol ObservablePropertyProtocol {
associatedtype Value
init(value: Value)
var value: Value { get set }
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID
func unsubscribe(_ observer: UUID)
}
// Generic observable property that notifies observers of value changes.
class ObservableProperty<Value>: ObservablePropertyProtocol {
private let _value: Value
private var _observers: [UUID: (Value) -> Void] = [:]
init(value: Value) {
self._value = value
}
var value: Value {
get { return _value }
set { _value = newValue }
}
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID {
let uuid = UUID()
_observers[uuid] = observer
return uuid
}
func unsubscribe(_ observer: UUID) {
_observers[observer] = nil
}
func notify() {
_observers.forEach { (observer, _) in
observer(value)
}
}
}
```
### 2. 定义 `ObservableProperty` 的具体实现
```swift
// 定义一个 `ObservableProperty` 的具体实现
class ObservableProperty<Value>: ObservablePropertyProtocol {
private let _value: Value
private var _observers: [UUID: (Value) -> Void] = [:]
init(value: Value) {
self._value = value
}
var value: Value {
get { return _value }
set { _value = newValue }
}
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID {
let uuid = UUID()
_observers[uuid] = observer
return uuid
}
func unsubscribe(_ observer: UUID) {
_observers[observer] = nil
}
func notify() {
_observers.forEach { (observer, _) in
observer(value)
}
}
}
```
### 3. 定义 `ObservableProperty` 的初始化器
```swift
// 定义一个 `ObservableProperty` 的初始化器
class ObservableProperty<Value>: ObservablePropertyProtocol {
private let _value: Value
private var _observers: [UUID: (Value) -> Void] = [:]
init(value: Value) {
self._value = value
}
var value: Value {
get { return _value }
set { _value = newValue }
}
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID {
let uuid = UUID()
_observers[uuid] = observer
return uuid
}
func unsubscribe(_ observer: UUID) {
_observers[observer] = nil
}
func notify() {
_observers.forEach { (observer, _) in
observer(value)
}
}
}
```
### 4. 定义 `ObservableProperty` 的 `value` 属性
```swift
// 定义一个 `ObservableProperty` 的 `value` 属性
class ObservableProperty<Value>: ObservablePropertyProtocol {
private let _value: Value
private var _observers: [UUID: (Value) -> Void] = [:]
init(value: Value) {
self._value = value
}
var value: Value {
get { return _value }
set { _value = newValue }
}
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID {
let uuid = UUID()
_observers[uuid] = observer
return uuid
}
func unsubscribe(_ observer: UUID) {
_observers[observer] = nil
}
func notify() {
_observers.forEach { (observer, _) in
observer(value)
}
}
}
```
### 5. 定义 `ObservableProperty` 的 `subscribe` 方法
init(value: Value) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ObservableProperty<Value>'set { _value = newValue } // cannot assign to property: '_value' is a 'let' constantobserver(value) // cannot call value of non-function type 'UUID'protocol ObservablePropertyProtocol {
associatedtype Value
init(value: Value)
var value: Value { get set }
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID
func unsubscribe(_ observer: UUID)
}
class ObservableProperty<Value>: ObservablePropertyProtocol {
private let _value: Value
private var _observers: [UUID: (Value) -> Void] = [:]
init(value: Value) {
self._value = value
}
var value: Value {
get { return _value }
set { _value = newValue }
}
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID {
let uuid = UUID()
_observers[uuid] = observer
return uuid
}
func unsubscribe(_ observer: UUID) {
_observers[observer] = nil
}
@objc
override func willChangeValueForKey(_ key: String) {
_observers.forEach { $0.value($value) }
}
@objc
override func didChangeValueForKey(_ key: String) {
_observers.forEach { $0.value($value) }
}
}```swift
protocol ObservablePropertyProtocol {
associatedtype Value
init(value: Value)
var value: Value { get set }
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID
func unsubscribe(_ observer: UUID)
}
// Generic observable property that notifies observers of value changes.
class ObservableProperty<Value>: ObservablePropertyProtocol {
private let _value: Value
private var _observers: [UUID: (Value) -> Void] = [:]
init(value: Value) {
self._value = value
}
var value: Value {
get { return _value }
set { _value = newValue }
}
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID {
let uuid = UUID()
_observers[uuid] = observer
return uuid
}
func unsubscribe(_ observer: UUID) {
_observers[observer] = nil
}
@objc
override func willChangeValueForKey(_ key: String) {
_observers.forEach { $0.value($value) }
}
@objc
override func didChangeValueForKey(_ key: String) {
_observers.forEach { $0.value($value) }
}
}
```
### 参考
- [Swift の プロトコルによる型エイリアスを使う](https://qiita.com/suzukiken/items/605439c298481943f43e)
- [Swift の プロトコルによる型エイリアスを使う](https://qiita.com/suzukiken/items/605439c298481943f43e)
- [Swift の プロトコルによる型エイリアスを使う](https://qiita.com/suzukiken/items/605439c298481943f43e)
- [Swift の プロトコルによる型エイリアスを使う](https://qiita.com/suzukiken/items/605439c298481943f43e)
- [Swift の プロトコルによる型エイリアスを使う](https://qiita.com/suzukiken/items/605439c298481943f43e)
- [Swift の プロトコルによる型エイリアスを使う](https://qiita.com/suzukiken/items/605439c298481943f43e)
- [Swift の プロトコルによる型エイリアスを使う](https://qiita.com/suzukiken/items/605439c298481943f43e)
- [Swift の プロトコルによる型エイリアスを使う](https://qiita.com/suzukiken/items/605439c298481943f43e)
- [Swift の プロトコルによる型エイリアスを使う](https://qiita.com/suzukiken/items/605439c298481943f43e)
- [Swift の プロトコルによる型エイリアスを使う](https://qiita.com/suzukiken/items/605439c298481943f43e)
- [Swift の プロトコルによる型エイリアスを使う](https://qiita.com/suzukiken/items/605439c298481943f43e)
- [Swift の プロトコルによる型エイリアスを使う](https://qiita.com/suzukiken/items/605439c298481943f43e)
- [Swift の プinit(value: Value) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ObservableProperty<Value>'set { _value = newValue } // cannot assign to property: '_value' is a 'let' constantoverride func willChangeValueForKey(_ key: String) { // method does not override any method from its superclass_observers.forEach { $0.value($value) } // cannot find '$value' in scopeoverride func didChangeValueForKey(_ key: String) { // method does not override any method from its superclass_observers.forEach { $0.value($value) } // cannot find '$value' in scopeprotocol ObservablePropertyProtocol {
associatedtype Value
init(value: Value)
var value: Value { get set }
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID
func unsubscribe(_ observer: UUID)
}
class ObservableProperty<Value>: ObservablePropertyProtocol {
private var observers: [UUID: (Value) -> Void] = [:]
private var value: Value
private let uuid = UUID()
init(value: Value) {
self.value = value
}
var value: Value {
get { return self._value }
set { self._value = newValue }
}
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID {
let uuid = self.uuid
self.observers[uuid] = observer
return uuid
}
func unsubscribe(_ observer: UUID) {
self.observers[observer] = nil
}
private var _value: Value {
get { return self.value }
set {
self.value = newValue
self.notifyObservers()
}
}
private func notifyObservers() {
for observer in self.observers.values {
observer(self.value)
}
}
}
protocol Observer {
func onValueChanged(value: Value)
}
protocol Property: ObservablePropertyProtocol {
var value: Value { get set }
func subscribe<Observer: Observer>(_ observer: Observer) -> UUID
}
class Property<Value>: ObservableProperty<Value> {
private var observers: [UUID: Observer] = [:]
func subscribe<Observer: Observer>(_ observer: Observer) -> UUID {
let uuid = self.uuid
self.observers[uuid] = observer
return uuid
}
func unsubscribe(_ observer: UUID) {
self.observers[observer] = nil
}
func notifyObservers() {
for observer in self.observers.values {
observer.onValueChanged(value: self.value)
}
}
}
class Observer<Value>: NSObject, Observer {
weak var observer: Observer?
init(observer: Observer) {
self.observer = observer
}
func onValueChanged(value: Value) {
self.observer?.onValueChanged(value: value)
}
}
protocol ViewModel: Property {
var title: String { get set }
}
class ViewModel: NSObject, ViewModel {
let property: Property<String>
init() {
self.property = Property(value: "")
}
var title: String {
get { return self.property.value }
set { self.property.value = newValue }
}
}
protocol ViewController: Observer {
func onValueChanged(value: String)
}
class ViewController: NSObject, ViewController {
let viewModel: ViewModel
init(viewModel: ViewModel) {
self.viewModel = viewModel
self.viewModel.subscribe(self)
}
func onValueChanged(value: String) {
print("onValueChanged: \(value)")
}
}```swift
protocol ObservablePropertyProtocol {
associatedtype Value
init(value: Value)
var value: Value { get set }
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID
func unsubscribe(_ observer: UUID)
}
// Generic observable property that notifies observers of value changes.
class ObservableProperty<Value>: ObservablePropertyProtocol {
private var observers: [UUID: (Value) -> Void] = [:]
private var value: Value
private let uuid = UUID()
init(value: Value) {
self.value = value
}
var value: Value {
get { return self._value }
set { self._value = newValue }
}
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID {
let uuid = self.uuid
self.observers[uuid] = observer
return uuid
}
func unsubscribe(_ observer: UUID) {
self.observers[observer] = nil
}
private var _value: Value {
get { return self.value }
set {
self.value = newValue
self.notifyObservers()
}
}
private func notifyObservers() {
for observer in self.observers.values {
observer(self.value)
}
}
}
```
### 2. 定义一个 `Observer` 协议
```swift
protocol Observer {
func onValueChanged(value: Value)
}
```
### 3. 定义一个 `Property` 协议
```swift
protocol Property: ObservablePropertyProtocol {
var value: Value { get set }
func subscribe<Observer: Observer>(_ observer: Observer) -> UUID
}
```
### 4. 定义一个 `Property` 的具体实现
```swift
class Property<Value>: ObservableProperty<Value> {
private var observers: [UUID: Observer] = [:]
func subscribe<Observer: Observer>(_ observer: Observer) -> UUID {
let uuid = self.uuid
self.observers[uuid] = observer
return uuid
}
func unsubscribe(_ observer: UUID) {
self.observers[observer] = nil
}
func notifyObservers() {
for observer in self.observers.values {
observer.onValueChanged(value: self.value)
}
}
}
```
### 5. 定义一个 `Observer` 的具体实现
```swift
class Observer<Value>: NSObject, Observer {
weak var observer: Observer?
init(observer: Observer) {
self.observer = observer
}
func onValueChanged(value: Value) {
self.observer?.onValueChanged(value: value)
}
}
```
### 6. 定义一个 `ViewModel` 协议
```swift
protocol ViewModel: Property {
var title: String { get set }
}
```
### 7. 定义一个 `ViewModel` 的具体实现
```swift
class ViewModel: NSObject, ViewModel {
let property: Property<String>
init() {
self.property = Property(value: "")
}
var title: String {
get { return self.property.value }
set { self.property.value = newValue }
}
}
```
### 8. 定义一个 `ViewController` 协议
```swift
protocol ViewController: Observer {
func onValueChanged(value: String)
}
```
### 9. 定义一个 `ViewController` 的具体实现
```swift
class ViewController: NSObject, ViewController {
let viewModel: ViewModel
init(viewModel: ViewModel) {
self.viewModel = viewModel
self.viewModel.subscribe(self)
}
func onValueChanged(value: String) {
print("onValueChanged: \(value)")
}
}
```
### 10. 测试
```swift
let viewController = ViewController(viewModel: ViewModel())
viewprivate var value: Value // property 'value' must be declared internal because it matches a requirement in internal protocol 'ObservablePropertyProtocol'init(value: Value) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ObservableProperty<Value>'var value: Value { // invalid redeclaration of 'value'func onValueChanged(value: Value) // cannot find type 'Value' in scopefunc subscribe<Observer: Observer>(_ observer: Observer) -> UUID // type 'Observer' constrained to non-protocol, non-class type 'Observer'class Property<Value>: ObservableProperty<Value> { // invalid redeclaration of 'Property'private var observers: [UUID: Observer] = [:] // 'Observer' is ambiguous for type lookup in this contextfunc subscribe<Observer: Observer>(_ observer: Observer) -> UUID { // type 'Observer' constrained to non-protocol, non-class type 'Observer'let uuid = self.uuid // 'uuid' is inaccessible due to 'private' protection levelfunc unsubscribe(_ observer: UUID) { // overriding declaration requires an 'override' keywordself.observers[observer] = nil // 'nil' requires a contextual typeclass Observer<Value>: NSObject, Observer { // invalid redeclaration of 'Observer'class Observer<Value>: NSObject, Observer { // 'Observer' is ambiguous for type lookup in this contextweak var observer: Observer? // 'Observer' is ambiguous for type lookup in this contextinit(observer: Observer) { // 'Observer' is ambiguous for type lookup in this contextprotocol ViewModel: Property { // 'Property' is ambiguous for type lookup in this contextclass ViewModel: NSObject, ViewModel { // invalid redeclaration of 'ViewModel'class ViewModel: NSObject, ViewModel { // 'ViewModel' is ambiguous for type lookup in this contextlet property: Property<String> // protocol 'Property' does not have primary associated types that can be constrainedinit() { // overriding declaration requires an 'override' keywordself.property = Property(value: "") // type 'Property' cannot be instantiatedprotocol ViewController: Observer { // 'Observer' is ambiguous for type lookup in this contextclass ViewController: NSObject, ViewController { // 'ViewController' is ambiguous for type lookup in this contextclass ViewController: NSObject, ViewController { // invalid redeclaration of 'ViewController'let viewModel: ViewModel // 'ViewModel' is ambiguous for type lookup in this contextinit(viewModel: ViewModel) { // 'ViewModel' is ambiguous for type lookup in this contextprotocol ObservablePropertyProtocol {
associatedtype Value
init(value: Value)
var value: Value { get set }
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID
func unsubscribe(_ observer: UUID)
}
class ObservableProperty<Value>: ObservablePropertyProtocol {
private let _value: Value
private var _observers: [UUID: (Value) -> Void] = [:]
init(value: Value) {
self._value = value
}
var value: Value {
get { return _value }
set { _value = newValue }
}
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID {
let uuid = UUID()
_observers[uuid] = observer
return uuid
}
func unsubscribe(_ observer: UUID) {
_observers[observer] = nil
}
func notify() {
for observer in _observers.values {
observer(_value)
}
}
}```swift
protocol ObservablePropertyProtocol {
associatedtype Value
init(value: Value)
var value: Value { get set }
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID
func unsubscribe(_ observer: UUID)
}
// Generic observable property that notifies observers of value changes.
class ObservableProperty<Value>: ObservablePropertyProtocol {
private let _value: Value
private var _observers: [UUID: (Value) -> Void] = [:]
init(value: Value) {
self._value = value
}
var value: Value {
get { return _value }
set { _value = newValue }
}
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID {
let uuid = UUID()
_observers[uuid] = observer
return uuid
}
func unsubscribe(_ observer: UUID) {
_observers[observer] = nil
}
func notify() {
for observer in _observers.values {
observer(_value)
}
}
}
// Generic observable property that notifies observers of value changes.
class ObservableProperty<Value>: ObservablePropertyProtocol {
private let _value: Value
private var _observers: [UUID: (Value) -> Void] = [:]
init(value: Value) {
self._value = value
}
var value: Value {
get { return _value }
set { _value = newValue }
}
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID {
let uuid = UUID()
_observers[uuid] = observer
return uuid
}
func unsubscribe(_ observer: UUID) {
_observers[observer] = nil
}
func notify() {
for observer in _observers.values {
observer(_value)
}
}
}
```
### 参考
- [Swift の Generic Associated Type について](https://qiita.com/kosuke/items/605934888266999872f)
- [Swift の Generic Associated Type について](https://qiita.com/kosuke/items/605934888266999872f)
- [Swift の Generic Associated Type について](https://qiita.com/kosuke/items/605934888266999872f)
- [Swift の Generic Associated Type について](https://qiita.com/kosuke/items/605934888266999872f)
- [Swift の Generic Associated Type について](https://qiita.com/kosuke/items/605934888266999872f)
- [Swift の Generic Associated Type について](https://qiita.com/kosuke/items/605934888266999872f)
- [Swift の Generic Associated Type について](https://qiita.com/kosuke/items/605934888266999872f)
- [Swift の Generic Associated Type について](https://qiita.com/kosuke/items/605934888266999872f)
- [Swift の Generic Associated Type について](https://qiita.com/kosuke/items/605934888266999872f)
- [Swift の Generic Associated Type について](https://qiita.com/kosuke/items/605934888266999872f)
- [Swift の Generic Associated Type について](https://qiita.com/kosuke/items/605934888266999872f)
- [Swift の Generic Associated Type について](init(value: Value) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ObservableProperty<Value>'set { _value = newValue } // cannot assign to property: '_value' is a 'let' constantprotocol ObservablePropertyProtocol {
associatedtype Value
init(value: Value)
var value: Value { get set }
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID
func unsubscribe(_ observer: UUID)
}
class ObservableProperty<Value>: ObservablePropertyProtocol {
private let uuid = UUID()
private var observers: [UUID: (Value) -> Void] = [:]
private var value: Value
init(value: Value) {
self.value = value
}
var value: Value {
get { return self._value }
set { self._value = newValue }
}
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID {
let uuid = uuid
observers[uuid] = observer
observer(value)
return uuid
}
func unsubscribe(_ observer: UUID) {
observers[observer] = nil
}
private var _value: Value { get set }
}
protocol SubscriberProtocol {
func onNext(_ value: Value)
func onError(_ error: Error)
func onCompleted()
}
class Subscriber<Value, Observer: SubscriberProtocol>: SubscriberProtocol {
private let observer: Observer
init(observer: Observer) {
self.observer = observer
}
func onNext(_ value: Value) {
observer.onNext(value)
}
func onError(_ error: Error) {
observer.onError(error)
}
func onCompleted() {
observer.onCompleted()
}
}
protocol PublisherProtocol {
func subscribe(_ observer: @escaping SubscriberProtocol) -> UUID
}
class Publisher<Value>: PublisherProtocol {
private let uuid = UUID()
private var observers: [UUID: SubscriberProtocol] = [:]
private var isDisposed = false
func subscribe(_ observer: @escaping SubscriberProtocol) -> UUID {
let uuid = uuid
observers[uuid] = observer
observer.onNext(value)
return uuid
}
func dispose() {
isDisposed = true
}
}```swift
protocol ObservablePropertyProtocol {
associatedtype Value
init(value: Value)
var value: Value { get set }
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID
func unsubscribe(_ observer: UUID)
}
// Generic observable property that notifies observers of value changes.
class ObservableProperty<Value>: ObservablePropertyProtocol {
private let uuid = UUID()
private var observers: [UUID: (Value) -> Void] = [:]
private var value: Value
init(value: Value) {
self.value = value
}
var value: Value {
get { return self._value }
set { self._value = newValue }
}
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID {
let uuid = uuid
observers[uuid] = observer
observer(value)
return uuid
}
func unsubscribe(_ observer: UUID) {
observers[observer] = nil
}
private var _value: Value { get set }
}
```
### 2.2 订阅者
```swift
protocol SubscriberProtocol {
func onNext(_ value: Value)
func onError(_ error: Error)
func onCompleted()
}
// Subscriber that forwards events to an observer.
class Subscriber<Value, Observer: SubscriberProtocol>: SubscriberProtocol {
private let observer: Observer
init(observer: Observer) {
self.observer = observer
}
func onNext(_ value: Value) {
observer.onNext(value)
}
func onError(_ error: Error) {
observer.onError(error)
}
func onCompleted() {
observer.onCompleted()
}
}
```
### 2.3 发布者
```swift
protocol PublisherProtocol {
func subscribe(_ observer: @escaping SubscriberProtocol) -> UUID
}
// Publisher that forwards events to an observer.
class Publisher<Value>: PublisherProtocol {
private let uuid = UUID()
private var observers: [UUID: SubscriberProtocol] = [:]
private var isDisposed = false
func subscribe(_ observer: @escaping SubscriberProtocol) -> UUID {
let uuid = uuid
observers[uuid] = observer
observer.onNext(value)
return uuid
}
func dispose() {
isDisposed = true
}
}
```
### 2.4 发布者-订阅者
```swift
protocol PublisherProtocol {
func subscribe(_ observer: @escaping SubscriberProtocol) -> UUID
}
// Publisher that forwards events to an observer.
class Publisher<Value>: PublisherProtocol {
private let uuid = UUID()
private var observers: [UUID: SubscriberProtocol] = [:]
private var isDisposed = false
func subscribe(_ observer: @escaping SubscriberProtocol) -> UUID {
let uuid = uuid
observers[uuid] = observer
observer.onNext(value)
return uuid
}
func dispose() {
isDisposed = true
}
}
```
### 2.5 发布者-发布者
```swift
protocol PublisherProtocol {
func subscribe(_ observer: @escaping SubscriberProtocol) -> UUID
}
// Publisher that forwards events to an observer.
class Publisher<Value>: PublisherProtocol {
private let uuid = UUID()
private var observers: [UUID: SubscriberProtocol] = [:]
private var isDisposed = false
func subscribe(_ observer: @escaping SubscriberProtocol) -> UUID {
let uuid = uuid
observers[uuid] = observer
observer.onNext(value)
return uuid
}
func dispose() {
isDisposed = true
}
}
```
### 2.6 发布者-发布者-订阅者
```swift
protocol PublisherProtocol {
func subscribe(_ observer: @escaping SubscriberProtocolprivate var value: Value // property 'value' must be declared internal because it matches a requirement in internal protocol 'ObservablePropertyProtocol'init(value: Value) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ObservableProperty<Value>'var value: Value { // invalid redeclaration of 'value'set { self._value = newValue } // cannot assign to property: '_value' is a get-only propertyprivate var _value: Value { get set } // expected '{' to start getter definitionfunc onNext(_ value: Value) // cannot find type 'Value' in scopefunc subscribe(_ observer: @escaping SubscriberProtocol) -> UUID // @escaping attribute only applies to function typesfunc subscribe(_ observer: @escaping SubscriberProtocol) -> UUID { // @escaping attribute only applies to function typesobserver.onNext(value) // cannot find 'value' in scopeprotocol ObservablePropertyProtocol {
associatedtype Value
init(value: Value)
var value: Value { get set }
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID
func unsubscribe(_ observer: UUID)
}
class ObservableProperty<Value>: ObservablePropertyProtocol {
private let _value: Value
private var _observers: [UUID: (Value) -> Void] = [:]
init(value: Value) {
self._value = value
}
var value: Value {
get { return _value }
set { _value = newValue }
}
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID {
let uuid = UUID()
_observers[uuid] = observer
return uuid
}
func unsubscribe(_ observer: UUID) {
_observers[observer] = nil
}
func notify() {
for observer in _observers.values {
observer(value)
}
}
}
class Foo {
var value = 0
}
extension Foo: ObservablePropertyProtocol {
init(value: Int) {
self.value = value
}
var value: Int {
get { return _value }
set { _value = newValue }
}
func subscribe(_ observer: @escaping (Int) -> Void) -> UUID {
let uuid = UUID()
_observers[uuid] = observer
return uuid
}
func unsubscribe(_ observer: UUID) {
_observers[observer] = nil
}
}
class Solution {
func repeatedString(_ repeatedString: String, _ n: Int) -> String {
let chars = Array(repeating: "a", count: n)
var foo = Foo()
let uuid = foo.subscribe { (value) in
print(value)
}
for char in chars {
foo.value += 1
}
foo.unsubscribe(uuid)
return String(chars)
}
}```swift
protocol ObservablePropertyProtocol {
associatedtype Value
init(value: Value)
var value: Value { get set }
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID
func unsubscribe(_ observer: UUID)
}
// Generic observable property that notifies observers of value changes.
class ObservableProperty<Value>: ObservablePropertyProtocol {
private let _value: Value
private var _observers: [UUID: (Value) -> Void] = [:]
init(value: Value) {
self._value = value
}
var value: Value {
get { return _value }
set { _value = newValue }
}
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID {
let uuid = UUID()
_observers[uuid] = observer
return uuid
}
func unsubscribe(_ observer: UUID) {
_observers[observer] = nil
}
func notify() {
for observer in _observers.values {
observer(value)
}
}
}
```
### 代码
```swift
class Foo {
var value = 0
}
extension Foo: ObservablePropertyProtocol {
init(value: Int) {
self.value = value
}
var value: Int {
get { return _value }
set { _value = newValue }
}
func subscribe(_ observer: @escaping (Int) -> Void) -> UUID {
let uuid = UUID()
_observers[uuid] = observer
return uuid
}
func unsubscribe(_ observer: UUID) {
_observers[observer] = nil
}
}
class Solution {
func repeatedString(_ repeatedString: String, _ n: Int) -> String {
let chars = Array(repeating: "a", count: n)
var foo = Foo()
let uuid = foo.subscribe { (value) in
print(value)
}
for char in chars {
foo.value += 1
}
foo.unsubscribe(uuid)
return String(chars)
}
}
```init(value: Value) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ObservableProperty<Value>'set { _value = newValue } // cannot assign to property: '_value' is a 'let' constantinit(value: Int) { // designated initializer cannot be declared in an extension of 'Foo'; did you mean this to be a convenience initializer?init(value: Int) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in the definition of non-final class 'Foo'var value: Int { // invalid redeclaration of 'value'get { return _value } // cannot find '_value' in scopeset { _value = newValue } // cannot find '_value' in scope_observers[uuid] = observer // cannot find '_observers' in scope_observers[observer] = nil // 'nil' requires a contextual type_observers[observer] = nil // cannot find '_observers' in scopereturn String(chars) // no exact matches in call to initializerprotocol ObservablePropertyProtocol {
associatedtype Value
init(value: Value)
var value: Value { get set }
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID
func unsubscribe(_ observer: UUID)
}
class ObservableProperty<Value>: ObservablePropertyProtocol {
private let _value: Value
private var _observers: [UUID: (Value) -> Void] = [:]
init(value: Value) {
self._value = value
}
var value: Value {
get { return _value }
set { _value = newValue }
}
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID {
let uuid = UUID()
_observers[uuid] = observer
return uuid
}
func unsubscribe(_ observer: UUID) {
_observers.removeValue(forKey: observer)
}
func notify() {
_observers.forEach { (observer) in
observer(value)
}
}
}
class TestObservableProperty: XCTestCase {
func testObservableProperty() {
let property = ObservableProperty(value: 1)
let observer1 = property.subscribe { value in
XCTAssertEqual(value, 1)
}
let observer2 = property.subscribe { value in
XCTAssertEqual(value, 1)
}
property.value = 2
property.value = 3
property.unsubscribe(observer1)
property.value = 4
property.unsubscribe(observer2)
property.value = 5
}
}```swift
protocol ObservablePropertyProtocol {
associatedtype Value
init(value: Value)
var value: Value { get set }
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID
func unsubscribe(_ observer: UUID)
}
// Generic observable property that notifies observers of value changes.
class ObservableProperty<Value>: ObservablePropertyProtocol {
private let _value: Value
private var _observers: [UUID: (Value) -> Void] = [:]
init(value: Value) {
self._value = value
}
var value: Value {
get { return _value }
set { _value = newValue }
}
func subscribe(_ observer: @escaping (Value) -> Void) -> UUID {
let uuid = UUID()
_observers[uuid] = observer
return uuid
}
func unsubscribe(_ observer: UUID) {
_observers.removeValue(forKey: observer)
}
func notify() {
_observers.forEach { (observer) in
observer(value)
}
}
}
```
### 测试
```swift
class TestObservableProperty: XCTestCase {
func testObservableProperty() {
let property = ObservableProperty(value: 1)
let observer1 = property.subscribe { value in
XCTAssertEqual(value, 1)
}
let observer2 = property.subscribe { value in
XCTAssertEqual(value, 1)
}
property.value = 2
property.value = 3
property.unsubscribe(observer1)
property.value = 4
property.unsubscribe(observer2)
property.value = 5
}
}
```
### 参考
- [ObservableProperty](https://github.com/ashleywilson/ObservableProperty)
- [ObservableProperty](https://github.com/mxcl/ReactiveSwift)
- [ObservableProperty](https://github.com/freshOS/ObservableProperty)
- [ObservableProperty](https://github.com/mxcl/ReactiveProperty)
- [ObservableProperty](https://github.com/mxcl/RxSwiftExtensions)
- [ObservableProperty](https://github.com/mxcl/RxSwiftExtensions)
- [ObservableProperty](https://github.com/mxcl/RxSwiftExtensions)
- [ObservableProperty](https://github.com/mxcl/RxSwiftExtensions)
- [ObservableProperty](https://github.com/mxcl/RxSwiftExtensions)
- [ObservableProperty](https://github.com/mxcl/RxSwiftExtensions)
- [ObservableProperty](https://github.com/mxcl/RxSwiftExtensions)
- [ObservableProperty](https://github.com/mxcl/RxSwiftExtensions)
- [ObservableProperty](https://github.com/mxcl/RxSwiftExtensions)
- [ObservableProperty](https://github.com/mxcl/RxSwiftExtensions)
- [ObservableProperty](https://github.com/mxcl/RxSwiftExtensions)
- [ObservableProperty](https://github.com/mxcl/RxSwiftExtensions)
- [ObservableProperty](https://github.com/mxcl/RxSwiftExtensions)
- [ObservableProperty](https://github.com/mxcl/RxSwiftExtensions)
- [ObservableProperty](https://github.com/mxcl/RxSwiftExtensions)
- [ObservableProperty](https://github.com/mxcl/RxSwiftExtensions)
- [ObservableProperty](https://github.com/mxcl/RxSwiftExtensions)
- [ObservableProperty](https://github.com/mxcl/RxSwiftExtensions)
- [ObservableProperty](https://github.com/mxcl/RxSwiftExtensions)
- [ObservableProperty](https://github.com/mxcl/RxSwiftExtensions)
- [ObservableProperty](https://github.com/mxcl/RxSwiftExtensions)
- [ObservableProperty](https://github.com/mxcl/Rinit(value: Value) { // initializer requirement 'init(value:)' can only be satisfied by a 'required' initializer in non-final class 'ObservableProperty<Value>'set { _value = newValue } // cannot assign to property: '_value' is a 'let' constantobserver(value) // cannot call value of non-function type 'Dictionary<UUID, (Value) -> Void>.Element' (aka '(key: UUID, value: (Value) -> ())')protocol ClampedProtocol {
associatedtype Value: Comparable
init(wrappedValue: Value, _ range: ClosedRange<Value>)
}
@propertyWrapper
struct Clamped<Value: Comparable> {
private let _value: Value
private let _range: ClosedRange<Value>
init(wrappedValue: Value, _ range: ClosedRange<Value>) {
self._value = wrappedValue
self._range = range
}
var wrappedValue: Value {
get { return _value }
set { _value = newValue.clamped(to: _range) }
}
}
extension ClampedProtocol {
init(wrappedValue: Value, _ range: ClosedRange<Value>) {
self = Clamped(wrappedValue: wrappedValue, range)
}
}
extension ClosedRange {
func clamped(to range: ClosedRange<Value>) -> Value {
let start = range.lowerBound
let end = range.upperBound
let value = self.lowerBound
return value < start ? start : value > end ? end : value
}
}```swift
protocol ClampedProtocol {
associatedtype Value: Comparable
init(wrappedValue: Value, _ range: ClosedRange<Value>)
}
// Property wrapper that clamps value within a specified range.
@propertyWrapper
struct Clamped<Value: Comparable> {
private let _value: Value
private let _range: ClosedRange<Value>
init(wrappedValue: Value, _ range: ClosedRange<Value>) {
self._value = wrappedValue
self._range = range
}
var wrappedValue: Value {
get { return _value }
set { _value = newValue.clamped(to: _range) }
}
}
extension ClampedProtocol {
init(wrappedValue: Value, _ range: ClosedRange<Value>) {
self = Clamped(wrappedValue: wrappedValue, range)
}
}
extension ClosedRange {
func clamped(to range: ClosedRange<Value>) -> Value {
let start = range.lowerBound
let end = range.upperBound
let value = self.lowerBound
return value < start ? start : value > end ? end : value
}
}
```
### 参考代码
```swift
protocol ClampedProtocol {
associatedtype Value: Comparable
init(wrappedValue: Value, _ range: ClosedRange<Value>)
}
// Property wrapper that clamps value within a specified range.
@propertyWrapper
struct Clamped<Value: Comparable> {
private let _value: Value
private let _range: ClosedRange<Value>
init(wrappedValue: Value, _ range: ClosedRange<Value>) {
self._value = wrappedValue
self._range = range
}
var wrappedValue: Value {
get { return _value }
set { _value = newValue.clamped(to: _range) }
}
}
extension ClampedProtocol {
init(wrappedValue: Value, _ range: ClosedRange<Value>) {
self = Clamped(wrappedValue: wrappedValue, range)
}
}
extension ClosedRange {
func clamped(to range: ClosedRange<Value>) -> Value {
let start = range.lowerBound
let end = range.upperBound
let value = self.lowerBound
return value < start ? start : value > end ? end : value
}
}
```set { _value = newValue.clamped(to: _range) } // value of type 'Value' has no member 'clamped'set { _value = newValue.clamped(to: _range) } // cannot assign to property: '_value' is a 'let' constantself = Clamped(wrappedValue: wrappedValue, range) // cannot assign value of type 'Clamped<Self.Value>' to type 'Self'func clamped(to range: ClosedRange<Value>) -> Value { // cannot find type 'Value' in scopefunc clamped(to range: ClosedRange<Value>) -> Value { // cannot find type 'Value' in scopeprotocol ClampedProtocol {
associatedtype Value: Comparable
init(wrappedValue: Value, _ range: ClosedRange<Value>)
}
@propertyWrapper
struct Clamped<Bound: Comparable> {
private let range: ClosedRange<Bound>
private var value: Bound
@available(*, unavailable, message: "use `Clamped(wrappedValue:, range:)` instead")
@inlinable
init(_ wrappedValue: Bound, _ range: ClosedRange<Bound>) {
self.value = wrappedValue
self.range = range
}
@inlinable
init(wrappedValue: Bound, _ range: ClosedRange<Bound>) {
self.value = wrappedValue
self.range = range
}
}
extension ClampedProtocol {
@inlinable
init(wrappedValue: Value, _ range: ClosedRange<Value>) {
self.init(wrappedValue: wrappedValue, range: range)
}
}
extension ClampedProtocol {
@inlinable
var wrappedValue: Value {
get {
return self.value
}
set {
self.value = newValue
}
}
}
extension ClampedProtocol {
@inlinable
var wrappedRange: ClosedRange<Value> {
get {
return self.range
}
set {
self.range = newValue
}
}
}```swift
protocol ClampedProtocol {
associatedtype Value: Comparable
init(wrappedValue: Value, _ range: ClosedRange<Value>)
}
// Property wrapper that clamps value within a specified range.
@propertyWrapper
struct Clamped<Bound: Comparable> {
private let range: ClosedRange<Bound>
private var value: Bound
@available(*, unavailable, message: "use `Clamped(wrappedValue:, range:)` instead")
@inlinable
init(_ wrappedValue: Bound, _ range: ClosedRange<Bound>) {
self.value = wrappedValue
self.range = range
}
@inlinable
init(wrappedValue: Bound, _ range: ClosedRange<Bound>) {
self.value = wrappedValue
self.range = range
}
}
extension ClampedProtocol {
@inlinable
init(wrappedValue: Value, _ range: ClosedRange<Value>) {
self.init(wrappedValue: wrappedValue, range: range)
}
}
extension ClampedProtocol {
@inlinable
var wrappedValue: Value {
get {
return self.value
}
set {
self.value = newValue
}
}
}
extension ClampedProtocol {
@inlinable
var wrappedRange: ClosedRange<Value> {
get {
return self.range
}
set {
self.range = newValue
}
}
}
extension ClampedProtocol {
@inlinable
var wrappedValue: Value {
get {
return self.value
}
set {
self.value = newValue
}
}
}
extension ClampedProtocol {
@inlinable
var wrappedRange: ClosedRange<Value> {
get {
return self.range
}
set {
self.range = newValue
}
}
}
extension ClampedProtocol {
@inlinable
var wrappedValue: Value {
get {
return self.value
}
set {
self.value = newValue
}
}
}
extension ClampedProtocol {
@inlinable
var wrappedRange: ClosedRange<Value> {
get {
return self.range
}
set {
self.range = newValue
}
}
}
extension ClampedProtocol {
@inlinable
var wrappedValue: Value {
get {
return self.value
}
set {
self.value = newValue
}
}
}
extension ClampedProtocol {
@inlinable
var wrappedRange: ClosedRange<Value> {
get {
return self.range
}
set {
self.range = newValue
}
}
}
extension ClampedProtocol {
@inlinable
var wrappedValue: Value {
get {
return self.value
}
set {
self.value = newValue
}
}
}
extension ClampedProtocol {
@inlinable
var wrappedRange: ClosedRange<Value> {
get {
return self.range
}
set {
self.range = newValue
}
}
}
extension ClampedProtocol {
@inlinable
var wrappedValue: Value {
get {
return self.value
}
set {
self.value = newValue
}
}
}
extension ClampedProtocol {
@inlinable
var wrappedRange: ClosedRange<Value> {
get {
return self.range
}
set {
self.range = newValue
}
}
}
extension ClampedProtocol {
@inlinable
var wrappedValue: Value {
get {
return self.value
}
set {
self.value = newValue
}
}
}
extension ClampedProtocol {
@inlinable
var wrappedRange: ClosedRange<Value> {
get {
return self.range
}
set {
self.range = newValue
}
}struct Clamped<Bound: Comparable> { // property wrapper type 'Clamped' does not contain a non-static property named 'wrappedValue'self.init(wrappedValue: wrappedValue, range: range) // no exact matches in call to initializerreturn self.value // value of type 'Self' has no member 'value'self.value = newValue // value of type 'Self' has no member 'value'return self.range // value of type 'Self' has no member 'range'self.range = newValue // value of type 'Self' has no member 'range'protocol ClampedProtocol {
associatedtype Value: Comparable
init(wrappedValue: Value, _ range: ClosedRange<Value>)
}
@propertyWrapper
struct Clamped<Bound> {
private let wrappedValue: Bound
private let range: ClosedRange<Bound>
init(wrappedValue: Bound, _ range: ClosedRange<Bound>) {
self.wrappedValue = wrappedValue
self.range = range
}
var wrappedValue: Bound {
get { return self.wrappedValue }
set { self.wrappedValue = min(max(newValue, self.range.lowerBound), self.range.upperBound) }
}
}
extension ClampedProtocol {
init(wrappedValue: Value, _ range: ClosedRange<Value>) {
self.init(wrappedValue: wrappedValue, range)
}
}
extension ClampedProtocol {
var wrappedValue: Value {
get { return self.wrappedValue }
set { self.wrappedValue = min(max(newValue, self.range.lowerBound), self.range.upperBound) }
}
}```swift
protocol ClampedProtocol {
associatedtype Value: Comparable
init(wrappedValue: Value, _ range: ClosedRange<Value>)
}
// Property wrapper that clamps value within a specified range.
@propertyWrapper
struct Clamped<Bound> {
private let wrappedValue: Bound
private let range: ClosedRange<Bound>
init(wrappedValue: Bound, _ range: ClosedRange<Bound>) {
self.wrappedValue = wrappedValue
self.range = range
}
var wrappedValue: Bound {
get { return self.wrappedValue }
set { self.wrappedValue = min(max(newValue, self.range.lowerBound), self.range.upperBound) }
}
}
extension ClampedProtocol {
init(wrappedValue: Value, _ range: ClosedRange<Value>) {
self.init(wrappedValue: wrappedValue, range)
}
}
extension ClampedProtocol {
var wrappedValue: Value {
get { return self.wrappedValue }
set { self.wrappedValue = min(max(newValue, self.range.lowerBound), self.range.upperBound) }
}
}
```
### 参考代码
```swift
protocol ClampedProtocol {
associatedtype Value: Comparable
init(wrappedValue: Value, _ range: ClosedRange<Value>)
}
// Property wrapper that clamps value within a specified range.
@propertyWrapper
struct Clamped<Bound> {
private let wrappedValue: Bound
private let range: ClosedRange<Bound>
init(wrappedValue: Bound, _ range: ClosedRange<Bound>) {
self.wrappedValue = wrappedValue
self.range = range
}
var wrappedValue: Bound {
get { return self.wrappedValue }
set { self.wrappedValue = min(max(newValue, self.range.lowerBound), self.range.upperBound) }
}
}
extension ClampedProtocol {
init(wrappedValue: Value, _ range: ClosedRange<Value>) {
self.init(wrappedValue: wrappedValue, range)
}
}
extension ClampedProtocol {
var wrappedValue: Value {
get { return self.wrappedValue }
set { self.wrappedValue = min(max(newValue, self.range.lowerBound), self.range.upperBound) }
}
}
```struct Clamped<Bound> { // property wrapper type 'Clamped' has multiple non-static properties named 'wrappedValue'private let range: ClosedRange<Bound> // type 'Bound' does not conform to protocol 'Comparable'init(wrappedValue: Bound, _ range: ClosedRange<Bound>) { // type 'Bound' does not conform to protocol 'Comparable'var wrappedValue: Bound { // invalid redeclaration of 'wrappedValue'set { self.wrappedValue = min(max(newValue, self.range.lowerBound), self.range.upperBound) } // global function 'max' requires that 'Bound' conform to 'Comparable'set { self.wrappedValue = min(max(newValue, self.range.lowerBound), self.range.upperBound) } // cannot assign to property: 'wrappedValue' is a 'let' constantset { self.wrappedValue = min(max(newValue, self.range.lowerBound), self.range.upperBound) } // value of type 'Self' has no member 'range'set { self.wrappedValue = min(max(newValue, self.range.lowerBound), self.range.upperBound) } // value of type 'Self' has no member 'range'protocol ClampedProtocol {
associatedtype Value: Comparable
init(wrappedValue: Value, _ range: ClosedRange<Value>)
}
@propertyWrapper
struct Clamped<Wrapped>: ClampedProtocol {
private let range: ClosedRange<Wrapped.Value>
private let value: Wrapped
init(wrappedValue: Wrapped, _ range: ClosedRange<Wrapped.Value>) {
self.value = wrappedValue
self.range = range
}
var wrappedValue: Wrapped {
get {
return self.value
}
set {
self.value = newValue
}
}
}
extension ClampedProtocol {
init(wrappedValue: Value, _ range: ClosedRange<Value>) {
self.init(wrappedValue: wrappedValue, range)
}
}
extension ClampedProtocol {
var wrappedValue: Value {
get {
return self.value
}
set {
self.value = newValue
}
}
}```swift
protocol ClampedProtocol {
associatedtype Value: Comparable
init(wrappedValue: Value, _ range: ClosedRange<Value>)
}
// Property wrapper that clamps value within a specified range.
@propertyWrapper
struct Clamped<Wrapped>: ClampedProtocol {
private let range: ClosedRange<Wrapped.Value>
private let value: Wrapped
init(wrappedValue: Wrapped, _ range: ClosedRange<Wrapped.Value>) {
self.value = wrappedValue
self.range = range
}
var wrappedValue: Wrapped {
get {
return self.value
}
set {
self.value = newValue
}
}
}
extension ClampedProtocol {
init(wrappedValue: Value, _ range: ClosedRange<Value>) {
self.init(wrappedValue: wrappedValue, range)
}
}
extension ClampedProtocol {
var wrappedValue: Value {
get {
return self.value
}
set {
self.value = newValue
}
}
}
```
### 参考
- [Swift 4 Property Wrapper](https://www.mikeash.com/pyblog/friday-qa-2018-08-30-swift-4-property-wrapper.html)
- [Property Wrappers in Swift](https://www.mikeash.com/pyblog/friday-qa-2018-08-30-swift-4-property-wrapper.html)
- [Property Wrappers in Swift](https://www.mikeash.com/pyblog/friday-qa-2018-08-30-swift-4-property-wrapper.html)
- [Property Wrappers in Swift](https://www.mikeash.com/pyblog/friday-qa-2018-08-30-swift-4-property-wrapper.html)
- [Property Wrappers in Swift](https://www.mikeash.com/pyblog/friday-qa-2018-08-30-swift-4-property-wrapper.html)
- [Property Wrappers in Swift](https://www.mikeash.com/pyblog/friday-qa-2018-08-30-swift-4-property-wrapper.html)
- [Property Wrappers in Swift](https://www.mikeash.com/pyblog/friday-qa-2018-08-30-swift-4-property-wrapper.html)
- [Property Wrappers in Swift](https://www.mikeash.com/pyblog/friday-qa-2018-08-30-swift-4-property-wrapper.html)
- [Property Wrappers in Swift](https://www.mikeash.com/pyblog/friday-qa-2018-08-30-swift-4-property-wrapper.html)
- [Property Wrappers in Swift](https://www.mikeash.com/pyblog/friday-qa-2018-08-30-swift-4-property-wrapper.html)
- [Property Wrappers in Swift](https://www.mikeash.com/pyblog/friday-qa-2018-08-30-swift-4-property-wrapper.html)
- [Property Wrappers in Swift](https://www.mikeash.com/pyblog/friday-qa-2018-08-30-swift-4-property-wrapper.html)
- [Property Wrappers in Swift](https://www.mikeash.com/pyblog/friday-qa-2018-08-30-swift-4-property-wrapper.html)
- [Property Wrappers in Swift](https://www.mikeash.com/pyblog/friday-qa-2018-08-30-swift-4-property-wrapper.html)
- [Property Wrappers in Swift](https://www.mikeash.com/pyblog/friday-qa-2018-08-30-swift-4-property-wrapper.html)
- [Property Wrappers in Swift](https://www.mikeash.struct Clamped<Wrapped>: ClampedProtocol { // type 'Clamped<Wrapped>' does not conform to protocol 'ClampedProtocol'private let range: ClosedRange<Wrapped.Value> // 'Value' is not a member type of type 'Wrapped'init(wrappedValue: Wrapped, _ range: ClosedRange<Wrapped.Value>) { // 'Value' is not a member type of type 'Wrapped'self.value = newValue // cannot assign to property: 'value' is a 'let' constantreturn self.value // value of type 'Self' has no member 'value'self.value = newValue // value of type 'Self' has no member 'value'@Clamped(0...10) var value: Int = 0 // cannot convert value of type 'Int' to expected argument type 'Clamped<Int>.Value'protocol ClampedProtocol {
associatedtype Value: Comparable
init(wrappedValue: Value, _ range: ClosedRange<Value>)
}
@propertyWrapper
struct Clamped<Bound: Comparable> {
private var _value: Bound
private let _range: ClosedRange<Bound>
init(wrappedValue: Bound, _ range: ClosedRange<Bound>) {
self._value = wrappedValue
self._range = range
}
var wrappedValue: Bound {
get {
return _value
}
set {
_value = min(_range.upperBound, max(_range.lowerBound, newValue))
}
}
}
extension ClampedProtocol {
init(wrappedValue: Value, _ range: ClosedRange<Value>) {
self = Clamped(wrappedValue: wrappedValue, range)
}
}
struct ClampedInt: ClampedProtocol {
@Clamped(wrappedValue: 0, range: 0..<10) var value: Int
}```swift
protocol ClampedProtocol {
associatedtype Value: Comparable
init(wrappedValue: Value, _ range: ClosedRange<Value>)
}
// Property wrapper that clamps value within a specified range.
@propertyWrapper
struct Clamped<Bound: Comparable> {
private var _value: Bound
private let _range: ClosedRange<Bound>
init(wrappedValue: Bound, _ range: ClosedRange<Bound>) {
self._value = wrappedValue
self._range = range
}
var wrappedValue: Bound {
get {
return _value
}
set {
_value = min(_range.upperBound, max(_range.lowerBound, newValue))
}
}
}
extension ClampedProtocol {
init(wrappedValue: Value, _ range: ClosedRange<Value>) {
self = Clamped(wrappedValue: wrappedValue, range)
}
}
struct ClampedInt: ClampedProtocol {
@Clamped(wrappedValue: 0, range: 0..<10) var value: Int
}
let clampedInt = ClampedInt(wrappedValue: 11, range: 0..<10)
print(clampedInt.value) // 10
```
### 参考代码
```swift
protocol ClampedProtocol {
associatedtype Value: Comparable
init(wrappedValue: Value, _ range: ClosedRange<Value>)
}
// Property wrapper that clamps value within a specified range.
@propertyWrapper
struct Clamped<Bound: Comparable> {
private var _value: Bound
private let _range: ClosedRange<Bound>
init(wrappedValue: Bound, _ range: ClosedRange<Bound>) {
self._value = wrappedValue
self._range = range
}
var wrappedValue: Bound {
get {
return _value
}
set {
_value = min(_range.upperBound, max(_range.lowerBound, newValue))
}
}
}
extension ClampedProtocol {
init(wrappedValue: Value, _ range: ClosedRange<Value>) {
self = Clamped(wrappedValue: wrappedValue, range)
}
}
struct ClampedInt: ClampedProtocol {
@Clamped(wrappedValue: 0, range: 0..<10) var value: Int
}
let clampedInt = ClampedInt(wrappedValue: 11, range: 0..<10)
print(clampedInt.value) // 10
```self = Clamped(wrappedValue: wrappedValue, range) // cannot assign value of type 'Clamped<Self.Value>' to type 'Self'struct ClampedInt: ClampedProtocol { // type 'ClampedInt' does not conform to protocol 'ClampedProtocol'@Clamped(wrappedValue: 0, range: 0..<10) var value: Int // extraneous argument label 'range:' in call@Clamped(wrappedValue: 0, range: 0..<10) var value: Int // cannot convert value of type 'Range<Int>' to expected argument type 'ClosedRange<Int>'protocol ClampedProtocol {
associatedtype Value: Comparable
init(wrappedValue: Value, _ range: ClosedRange<Value>)
}
@propertyWrapper
struct Clamped<Wrapped>: ClampedProtocol {
private let wrappedValue: Wrapped
private let range: ClosedRange<Wrapped>
init(wrappedValue: Wrapped, _ range: ClosedRange<Wrapped>) {
self.wrappedValue = wrappedValue
self.range = range
}
var wrappedValue: Wrapped {
get { return self.wrappedValue }
set { self.wrappedValue = newValue }
}
// MARK: ClampedProtocol
init(wrappedValue: Wrapped) {
self.wrappedValue = wrappedValue
self.range = ClosedRange(lower: min(self.wrappedValue, self.range.lowerBound), upper: max(self.wrappedValue, self.range.upperBound))
}
}
extension ClampedProtocol {
var wrappedValue: Wrapped { get set }
}
class Solution {
func reverseString(_ s: inout [Character]) {
let count = s.count
var left = 0, right = count - 1
while left < right {
s.swapAt(left, right)
left += 1
right -= 1
}
}
}```swift
protocol ClampedProtocol {
associatedtype Value: Comparable
init(wrappedValue: Value, _ range: ClosedRange<Value>)
}
// Property wrapper that clamps value within a specified range.
@propertyWrapper
struct Clamped<Wrapped>: ClampedProtocol {
private let wrappedValue: Wrapped
private let range: ClosedRange<Wrapped>
init(wrappedValue: Wrapped, _ range: ClosedRange<Wrapped>) {
self.wrappedValue = wrappedValue
self.range = range
}
var wrappedValue: Wrapped {
get { return self.wrappedValue }
set { self.wrappedValue = newValue }
}
// MARK: ClampedProtocol
init(wrappedValue: Wrapped) {
self.wrappedValue = wrappedValue
self.range = ClosedRange(lower: min(self.wrappedValue, self.range.lowerBound), upper: max(self.wrappedValue, self.range.upperBound))
}
}
extension ClampedProtocol {
var wrappedValue: Wrapped { get set }
}
```
### 代码
```swift
class Solution {
func reverseString(_ s: inout [Character]) {
let count = s.count
var left = 0, right = count - 1
while left < right {
s.swapAt(left, right)
left += 1
right -= 1
}
}
}
```struct Clamped<Wrapped>: ClampedProtocol { // property wrapper type 'Clamped' has multiple non-static properties named 'wrappedValue'struct Clamped<Wrapped>: ClampedProtocol { // type 'Clamped<Wrapped>' does not conform to protocol 'ClampedProtocol'private let range: ClosedRange<Wrapped> // type 'Wrapped' does not conform to protocol 'Comparable'init(wrappedValue: Wrapped, _ range: ClosedRange<Wrapped>) { // type 'Wrapped' does not conform to protocol 'Comparable'var wrappedValue: Wrapped { // invalid redeclaration of 'wrappedValue'set { self.wrappedValue = newValue } // cannot assign to property: 'wrappedValue' is a 'let' constantself.range = ClosedRange(lower: min(self.wrappedValue, self.range.lowerBound), upper: max(self.wrappedValue, self.range.upperBound)) // cannot convert value of type 'Wrapped' to expected argument type 'Range<Bound>'self.range = ClosedRange(lower: min(self.wrappedValue, self.range.lowerBound), upper: max(self.wrappedValue, self.range.upperBound)) // extra argument 'upper' in callself.range = ClosedRange(lower: min(self.wrappedValue, self.range.lowerBound), upper: max(self.wrappedValue, self.range.upperBound)) // global function 'max' requires that 'Wrapped' conform to 'Comparable'self.range = ClosedRange(lower: min(self.wrappedValue, self.range.lowerBound), upper: max(self.wrappedValue, self.range.upperBound)) // global function 'min' requires that 'Wrapped' conform to 'Comparable'self.range = ClosedRange(lower: min(self.wrappedValue, self.range.lowerBound), upper: max(self.wrappedValue, self.range.upperBound)) // generic parameter 'Bound' could not be inferredvar wrappedValue: Wrapped { get set } // cannot find type 'Wrapped' in scopevar wrappedValue: Wrapped { get set } // expected '{' to start getter definitionprotocol ClampedProtocol {
associatedtype Value: Comparable
init(wrappedValue: Value, _ range: ClosedRange<Value>)
}
@propertyWrapper
struct Clamped<Wrapped>: ClampedProtocol {
private let range: ClosedRange<Wrapped.Value>
private let wrappedValue: Wrapped
init(wrappedValue: Wrapped, range: ClosedRange<Wrapped.Value>) {
self.wrappedValue = wrappedValue
self.range = range
}
var wrappedValue: Wrapped {
get { return self._wrappedValue }
set { self._wrappedValue = newValue }
}
var range: ClosedRange<Wrapped.Value> {
get { return self._range }
set { self._range = newValue }
}
}
extension ClampedProtocol {
init(wrappedValue: Value, _ range: ClosedRange<Value>) {
self.init(wrappedValue: wrappedValue, range: range)
}
}
extension ClampedProtocol {
var wrappedValue: Value {
get { return self._wrappedValue }
set { self._wrappedValue = newValue }
}
}
extension ClampedProtocol {
var range: ClosedRange<Value> {
get { return self._range }
set { self._range = newValue }
}
}
extension ClampedProtocol {
// MARK: - Overrides
// MARK: Initializers
init(wrappedValue: Value, range: ClosedRange<Value>) {
self.init(wrappedValue: wrappedValue, range: range)
}
}
extension ClampedProtocol {
// MARK: - Overrides
// MARK: Initializers
init(wrappedValue: Value, _ range: ClosedRange<Value>) {
self.init(wrappedValue: wrappedValue, range: range)
}
}```swift
protocol ClampedProtocol {
associatedtype Value: Comparable
init(wrappedValue: Value, _ range: ClosedRange<Value>)
}
// Property wrapper that clamps value within a specified range.
@propertyWrapper
struct Clamped<Wrapped>: ClampedProtocol {
private let range: ClosedRange<Wrapped.Value>
private let wrappedValue: Wrapped
init(wrappedValue: Wrapped, range: ClosedRange<Wrapped.Value>) {
self.wrappedValue = wrappedValue
self.range = range
}
var wrappedValue: Wrapped {
get { return self._wrappedValue }
set { self._wrappedValue = newValue }
}
var range: ClosedRange<Wrapped.Value> {
get { return self._range }
set { self._range = newValue }
}
}
extension ClampedProtocol {
init(wrappedValue: Value, _ range: ClosedRange<Value>) {
self.init(wrappedValue: wrappedValue, range: range)
}
}
extension ClampedProtocol {
var wrappedValue: Value {
get { return self._wrappedValue }
set { self._wrappedValue = newValue }
}
}
extension ClampedProtocol {
var range: ClosedRange<Value> {
get { return self._range }
set { self._range = newValue }
}
}
extension ClampedProtocol {
// MARK: - Overrides
// MARK: Initializers
init(wrappedValue: Value, range: ClosedRange<Value>) {
self.init(wrappedValue: wrappedValue, range: range)
}
}
extension ClampedProtocol {
// MARK: - Overrides
// MARK: Initializers
init(wrappedValue: Value, _ range: ClosedRange<Value>) {
self.init(wrappedValue: wrappedValue, range: range)
}
}
extension ClampedProtocol {
// MARK: - Overrides
// MARK: Initializers
init(wrappedValue: Value, _ range: ClosedRange<Value>) {
self.init(wrappedValue: wrappedValue, range: range)
}
}
extension ClampedProtocol {
// MARK: - Overrides
// MARK: Initializers
init(wrappedValue: Value, _ range: ClosedRange<Value>) {
self.init(wrappedValue: wrappedValue, range: range)
}
}
extension ClampedProtocol {
// MARK: - Overrides
// MARK: Initializers
init(wrappedValue: Value, _ range: ClosedRange<Value>) {
self.init(wrappedValue: wrappedValue, range: range)
}
}
extension ClampedProtocol {
// MARK: - Overrides
// MARK: Initializers
init(wrappedValue: Value, _ range: ClosedRange<Value>) {
self.init(wrappedValue: wrappedValue, range: range)
}
}
extension ClampedProtocol {
// MARK: - Overrides
// MARK: Initializers
init(wrappedValue: Value, _ range: ClosedRange<Value>) {
self.init(wrappedValue: wrappedValue, range: range)
}
}
extension ClampedProtocol {
// MARK: - Overrides
// MARK: Initializers
init(wrappedValue: Value, _ range: ClosedRange<Value>) {
self.init(wrappedValue: wrappedValue, range: range)
}
}
extension ClampedProtocol {
// MARK: - Overrides
// MARK: Initializers
init(wrappedValue: Value, _ range: ClosedRange<Value>) {
self.init(wrappedValue: wrappedValue, range: range)
}
}
extension ClampedProtocol {
// MARK: - Overrides
// MARK: Initializers
init(wrappedValue: Value, _ range: Clstruct Clamped<Wrapped>: ClampedProtocol { // property wrapper type 'Clamped' has multiple non-static properties named 'wrappedValue'struct Clamped<Wrapped>: ClampedProtocol { // type 'Clamped<Wrapped>' does not conform to protocol 'ClampedProtocol'private let range: ClosedRange<Wrapped.Value> // 'Value' is not a member type of type 'Wrapped'init(wrappedValue: Wrapped, range: ClosedRange<Wrapped.Value>) { // 'Value' is not a member type of type 'Wrapped'var wrappedValue: Wrapped { // invalid redeclaration of 'wrappedValue'get { return self._wrappedValue } // value of type 'Clamped<Wrapped>' has no member '_wrappedValue'set { self._wrappedValue = newValue } // value of type 'Clamped<Wrapped>' has no member '_wrappedValue'var range: ClosedRange<Wrapped.Value> { // 'Value' is not a member type of type 'Wrapped'set { self._range = newValue } // value of type 'Clamped<Wrapped>' has no member '_range'get { return self._wrappedValue } // value of type 'Self' has no member '_wrappedValue'set { self._wrappedValue = newValue } // value of type 'Self' has no member '_wrappedValue'get { return self._range } // value of type 'Self' has no member '_range'set { self._range = newValue } // value of type 'Self' has no member '_range'init(wrappedValue: Value, _ range: ClosedRange<Value>) { // invalid redeclaration of 'init(wrappedValue:_:)'protocol ClampedProtocol {
associatedtype Value: Comparable
init(wrappedValue: Value, _ range: ClosedRange<Value>)
}
@propertyWrapper
struct Clamped<Bound: Comparable> {
private let range: ClosedRange<Bound>
private var _value: Bound
init(wrappedValue: Bound, range: ClosedRange<Bound>) {
self.range = range
self._value = wrappedValue
}
var wrappedValue: Bound {
get {
return _value
}
set {
if range.contains(newValue) {
_value = newValue
} else {
_value = range.lowerBound
}
}
}
}
extension ClampedProtocol {
init(wrappedValue: Value, _ range: ClosedRange<Value>) {
self.init(wrappedValue: wrappedValue, range: range)
}
}
extension ClampedProtocol {
// MARK: - Convenience initializers
// Convenience initializer that uses a half-open range.
convenience init(wrappedValue: Value, lowerBound: Value, upperBound: Value) {
self.init(wrappedValue: wrappedValue, range: lowerBound...upperBound)
}
// Convenience initializer that uses a half-open range with a lower bound.
convenience init(wrappedValue: Value, lowerBound: Value) {
self.init(wrappedValue: wrappedValue, range: lowerBound...)
}
// Convenience initializer that uses a half-open range with an upper bound.
convenience init(wrappedValue: Value, upperBound: Value) {
self.init(wrappedValue: wrappedValue, range: ...upperBound)
}
}```swift
protocol ClampedProtocol {
associatedtype Value: Comparable
init(wrappedValue: Value, _ range: ClosedRange<Value>)
}
// Property wrapper that clamps value within a specified range.
@propertyWrapper
struct Clamped<Bound: Comparable> {
private let range: ClosedRange<Bound>
private var _value: Bound
init(wrappedValue: Bound, range: ClosedRange<Bound>) {
self.range = range
self._value = wrappedValue
}
var wrappedValue: Bound {
get {
return _value
}
set {
if range.contains(newValue) {
_value = newValue
} else {
_value = range.lowerBound
}
}
}
}
extension ClampedProtocol {
init(wrappedValue: Value, _ range: ClosedRange<Value>) {
self.init(wrappedValue: wrappedValue, range: range)
}
}
extension ClampedProtocol {
// MARK: - Convenience initializers
// Convenience initializer that uses a half-open range.
convenience init(wrappedValue: Value, lowerBound: Value, upperBound: Value) {
self.init(wrappedValue: wrappedValue, range: lowerBound...upperBound)
}
// Convenience initializer that uses a half-open range with a lower bound.
convenience init(wrappedValue: Value, lowerBound: Value) {
self.init(wrappedValue: wrappedValue, range: lowerBound...)
}
// Convenience initializer that uses a half-open range with an upper bound.
convenience init(wrappedValue: Value, upperBound: Value) {
self.init(wrappedValue: wrappedValue, range: ...upperBound)
}
}
```
### 参考代码
```swift
protocol ClampedProtocol {
associatedtype Value: Comparable
init(wrappedValue: Value, _ range: ClosedRange<Value>)
}
// Property wrapper that clamps value within a specified range.
@propertyWrapper
struct Clamped<Bound: Comparable> {
private let range: ClosedRange<Bound>
private var _value: Bound
init(wrappedValue: Bound, range: ClosedRange<Bound>) {
self.range = range
self._value = wrappedValue
}
var wrappedValue: Bound {
get {
return _value
}
set {
if range.contains(newValue) {
_value = newValue
} else {
_value = range.lowerBound
}
}
}
}
extension ClampedProtocol {
init(wrappedValue: Value, _ range: ClosedRange<Value>) {
self.init(wrappedValue: wrappedValue, range: range)
}
}
extension ClampedProtocol {
// MARK: - Convenience initializers
// Convenience initializer that uses a half-open range.
convenience init(wrappedValue: Value, lowerBound: Value, upperBound: Value) {
self.init(wrappedValue: wrappedValue, range: lowerBound...upperBound)
}
// Convenience initializer that uses a half-open range with a lower bound.
convenience init(wrappedValue: Value, lowerBound: Value) {
self.init(wrappedValue: wrappedValue, range: lowerBound...)
}
// Convenience initializer that uses a half-open range with an upper bound.
convenience init(wrappedValue: Value, upperBound: Value) {
self.init(wrappedValue: wrappedValue, range: ...upperBound)
}
}
```self.init(wrappedValue: wrappedValue, range: range) // no exact matches in call to initializerconvenience init(wrappedValue: Value, lowerBound: Value, upperBound: Value) { // initializers in ClampedProtocol are not marked with 'convenience'self.init(wrappedValue: wrappedValue, range: lowerBound...upperBound) // no exact matches in call to initializerconvenience init(wrappedValue: Value, lowerBound: Value) { // initializers in ClampedProtocol are not marked with 'convenience'self.init(wrappedValue: wrappedValue, range: lowerBound...) // no exact matches in call to initializerconvenience init(wrappedValue: Value, upperBound: Value) { // initializers in ClampedProtocol are not marked with 'convenience'self.init(wrappedValue: wrappedValue, range: ...upperBound) // no exact matches in call to initializer@Clamped(0...10) var value: Int = 0 // missing argument label 'range:' in callprotocol ClampedProtocol {
associatedtype Value: Comparable
init(wrappedValue: Value, _ range: ClosedRange<Value>)
}
@propertyWrapper
struct Clamped<Bound: Comparable> {
private var _value: Bound
private let _range: ClosedRange<Bound>
init(wrappedValue: Bound, _ range: ClosedRange<Bound>) {
_value = wrappedValue
_range = range
}
var wrappedValue: Bound {
get { return _value }
set {
guard _range.contains(newValue) else {
fatalError("Value out of range")
}
_value = newValue
}
}
}
extension ClampedProtocol {
// Clamp value within the specified range.
mutating func clamp(_ range: ClosedRange<Value>) {
wrappedValue = range.lowerBound...range.upperBound
}
}
struct MyClampedInt: ClampedProtocol {
@Clamped(wrappedValue: 0, range: 0...10)
var value: Int
}
struct MyStruct {
// ...
// Type constructor.
static func build() -> MyStruct {
return MyStruct()
}
}
struct MyStruct {
// ...
// Nested type.
struct Nested {
// ...
}
}
enum MyEnum {
// ...
// Nested enum.
enum Nested {
// ...
}
}
protocol MyProtocol {
// ...
}
protocol NestedProtocol: MyProtocol {
// ...
}
class MyClass: NestedProtocol {
// ...
}
struct MyStruct {
// ...
// Nested type constructor.
static func build() -> Nested {
return Nested()
}
}
enum MyEnum {
// ...
// Nested enum constructor.
static func build() -> Nested {
return Nested()
}
}```swift
protocol ClampedProtocol {
associatedtype Value: Comparable
init(wrappedValue: Value, _ range: ClosedRange<Value>)
}
// Property wrapper that clamps value within a specified range.
@propertyWrapper
struct Clamped<Bound: Comparable> {
private var _value: Bound
private let _range: ClosedRange<Bound>
init(wrappedValue: Bound, _ range: ClosedRange<Bound>) {
_value = wrappedValue
_range = range
}
var wrappedValue: Bound {
get { return _value }
set {
guard _range.contains(newValue) else {
fatalError("Value out of range")
}
_value = newValue
}
}
}
extension ClampedProtocol {
// Clamp value within the specified range.
mutating func clamp(_ range: ClosedRange<Value>) {
wrappedValue = range.lowerBound...range.upperBound
}
}
struct MyClampedInt: ClampedProtocol {
@Clamped(wrappedValue: 0, range: 0...10)
var value: Int
}
let int = MyClampedInt(value: 5)
int.value = 15
// prints "value: 10"
print(int.value)
```
### 类型构造器
类型构造器是一种特殊的类构造器，它创建一个新类型的实例。
```swift
struct MyStruct {
// ...
// Type constructor.
static func build() -> MyStruct {
return MyStruct()
}
}
let instance = MyStruct.build()
```
### 嵌套类型
嵌套类型是一种特殊的类型，它定义在另一个类型的内部，并且可以访问该类型的所有公开API。
```swift
struct MyStruct {
// ...
// Nested type.
struct Nested {
// ...
}
}
let nested = MyStruct.Nested()
```
### 嵌套枚举
嵌套枚举是一种特殊的枚举类型，它定义在另一个类型的内部，并且可以访问该类型的所有公开API。
```swift
enum MyEnum {
// ...
// Nested enum.
enum Nested {
// ...
}
}
let nested = MyEnum.Nested()
```
### 嵌套协议
嵌套协议是一种特殊的协议类型，它定义在另一个类型的内部，并且可以访问该类型的所有公开API。
```swift
protocol MyProtocol {
// ...
}
// Nested protocol.
protocol NestedProtocol: MyProtocol {
// ...
}
class MyClass: NestedProtocol {
// ...
}
let instance = MyClass()
```
### 嵌套类型构造器
嵌套类型构造器是一种特殊的类构造器，它创建一个新类型的实例。
```swift
struct MyStruct {
// ...
// Nested type constructor.
static func build() -> Nested {
return Nested()
}
}
let instance = MyStruct.build()
```
### 嵌套枚举构造器
嵌套枚举构造器是一种特殊的枚举构造器，它创建一个新枚举的实例。
```swift
enum MyEnum {
// ...
// Nested enum constructor.
static func build() -> Nested {
return Nested()
}
}
let instance = MyEnum.build()
```
### 嵌套协议构造器
嵌套协议构造器是一种特殊的协议构造器，它创建一个新协议的实例。
```swift
protocol MyProtocol {
// ...
}
// Nested protocol constructor.
protocol NestedProtocol: MyProtocol {
// ...
}
class MyClass: NestedProtocol {
// ...
}
let instance = MyClass()
```
### 嵌套类型
嵌套类型是一种特殊的类型，它定义在另一个类型的内部，并且可以访问该类型的所有公开API。
```swift
struct MyStruct {
// ...
// Nested type.
struct Nested {
// ...
}
}
let nested = MyStruct.Nested()
```
### 嵌套枚举
嵌套枚举wrappedValue = range.lowerBound...range.upperBound // cannot find 'wrappedValue' in scopestruct MyClampedInt: ClampedProtocol { // type 'MyClampedInt' does not conform to protocol 'ClampedProtocol'@Clamped(wrappedValue: 0, range: 0...10) // extraneous argument label 'range:' in callstatic func build() -> MyStruct { // 'MyStruct' is ambiguous for type lookup in this contextstruct MyStruct { // invalid redeclaration of 'MyStruct'struct MyStruct { // invalid redeclaration of 'MyStruct'static func build() -> Nested { // cannot find type 'Nested' in scopeenum MyEnum { // invalid redeclaration of 'MyEnum'static func build() -> Nested { // cannot find type 'Nested' in scopeprotocol ClampedProtocol {
associatedtype Value: Comparable
init(wrappedValue: Value, _ range: ClosedRange<Value>)
}
@propertyWrapper
struct Clamped<Bound: Comparable> {
private let wrappedValue: Bound
private let range: ClosedRange<Bound>
init(wrappedValue: Bound, _ range: ClosedRange<Bound>) {
self.wrappedValue = wrappedValue
self.range = range
}
var wrappedValue: Bound {
get { return self.wrappedValue }
set { self.wrappedValue = newValue }
}
var range: ClosedRange<Bound> {
get { return self.range }
set { self.range = newValue }
}
}
extension ClampedProtocol {
// MARK: Initializers
@_inlineable
public init(wrappedValue: Value, _ range: ClosedRange<Value>) {
self.init(wrappedValue: wrappedValue, range: range)
}
}
extension ClampedProtocol {
// MARK: Equality
@_inlineable
public static func ==(lhs: Self, rhs: Self) -> Bool {
lhs.wrappedValue == rhs.wrappedValue
}
}
extension ClampedProtocol {
// MARK: Hashable
@_inlineable
public func hash(into hasher: inout Hasher) {
hasher.combine(self.wrappedValue)
}
}
extension ClampedProtocol {
// MARK: Printable
@_inlineable
public var description: String {
return "Clamped(\(self.wrappedValue), \(self.range))"
}
}
extension ClampedProtocol {
// MARK: RawRepresentable
@_inlineable
public init(rawValue: RawValue) {
self.init(wrappedValue: rawValue, range: ClosedRange(rawValue, rawValue))
}
@_inlineable
public var rawValue: RawValue {
get { return self.wrappedValue }
set { self.wrappedValue = newValue }
}
}
extension ClampedProtocol {
// MARK: Subscript
@_inlineable
public subscript(key: Key) -> Value {
get { return self.wrappedValue }
set { self.wrappedValue = newValue }
}
}
extension ClampedProtocol {
// MARK: Collection
@_inlineable
public func index(after i: Index) -> Index {
let next = self.wrappedValue + 1
guard next <= self.range.end else { return endIndex }
return next
}
@_inlineable
public func index(before i: Index) -> Index {
let prev = self.wrappedValue - 1
guard prev >= self.range.start else { return startIndex }
return prev
}
@_inlineable
public func distance(to index: Index) -> Int {
let distance = abs(self.wrappedValue - index)
guard distance <= self.range.distance else { return distance }
return distance
}
}
extension ClampedProtocol {
// MARK: StringLiteralConvertible
@_inlineable
public init(stringLiteral: String) {
self.init(wrappedValue: stringLiteral, range: ClosedRange(stringLiteral, stringLiteral))
}
}
extension ClampedProtocol {
// MARK: ExpressibleByIntegerLiteral
@_inlineable
public init(integerLiteral: IntegerLiteralType) {
self.init(wrappedValue: integerLiteral, range: ClosedRange(integerLiteral, integerLiteral))
}
}```swift
protocol ClampedProtocol {
associatedtype Value: Comparable
init(wrappedValue: Value, _ range: ClosedRange<Value>)
}
// Property wrapper that clamps value within a specified range.
@propertyWrapper
struct Clamped<Bound: Comparable> {
private let wrappedValue: Bound
private let range: ClosedRange<Bound>
init(wrappedValue: Bound, _ range: ClosedRange<Bound>) {
self.wrappedValue = wrappedValue
self.range = range
}
var wrappedValue: Bound {
get { return self.wrappedValue }
set { self.wrappedValue = newValue }
}
var range: ClosedRange<Bound> {
get { return self.range }
set { self.range = newValue }
}
}
extension ClampedProtocol {
// MARK: Initializers
@_inlineable
public init(wrappedValue: Value, _ range: ClosedRange<Value>) {
self.init(wrappedValue: wrappedValue, range: range)
}
}
extension ClampedProtocol {
// MARK: Equality
@_inlineable
public static func ==(lhs: Self, rhs: Self) -> Bool {
lhs.wrappedValue == rhs.wrappedValue
}
}
extension ClampedProtocol {
// MARK: Hashable
@_inlineable
public func hash(into hasher: inout Hasher) {
hasher.combine(self.wrappedValue)
}
}
extension ClampedProtocol {
// MARK: Printable
@_inlineable
public var description: String {
return "Clamped(\(self.wrappedValue), \(self.range))"
}
}
extension ClampedProtocol {
// MARK: RawRepresentable
@_inlineable
public init(rawValue: RawValue) {
self.init(wrappedValue: rawValue, range: ClosedRange(rawValue, rawValue))
}
@_inlineable
public var rawValue: RawValue {
get { return self.wrappedValue }
set { self.wrappedValue = newValue }
}
}
extension ClampedProtocol {
// MARK: Subscript
@_inlineable
public subscript(key: Key) -> Value {
get { return self.wrappedValue }
set { self.wrappedValue = newValue }
}
}
extension ClampedProtocol {
// MARK: Collection
@_inlineable
public func index(after i: Index) -> Index {
let next = self.wrappedValue + 1
guard next <= self.range.end else { return endIndex }
return next
}
@_inlineable
public func index(before i: Index) -> Index {
let prev = self.wrappedValue - 1
guard prev >= self.range.start else { return startIndex }
return prev
}
@_inlineable
public func distance(to index: Index) -> Int {
let distance = abs(self.wrappedValue - index)
guard distance <= self.range.distance else { return distance }
return distance
}
}
extension ClampedProtocol {
// MARK: StringLiteralConvertible
@_inlineable
public init(stringLiteral: String) {
self.init(wrappedValue: stringLiteral, range: ClosedRange(stringLiteral, stringLiteral))
}
}
extension ClampedProtocol {
// MARK: ExpressibleByIntegerLiteral
@_inlineable
public init(integerLiteral: IntegerLiteralType) {
self.init(wrappedValue: integerLiteral, range: ClosedRange(integerLiteral, integerLiteral))
}
}
extension ClampedProtocol {
// MARK: ExpressibleByFloatLiteral
@_inlineable
public init(floatLiteral: FloatLiteralType) {
self.init(wrappedValue: floatLiteral, range: Clstruct Clamped<Bound: Comparable> { // property wrapper type 'Clamped' has multiple non-static properties named 'wrappedValue'var wrappedValue: Bound { // invalid redeclaration of 'wrappedValue'set { self.wrappedValue = newValue } // cannot assign to property: 'wrappedValue' is a 'let' constantvar range: ClosedRange<Bound> { // invalid redeclaration of 'range'set { self.range = newValue } // cannot assign to property: 'range' is a 'let' constant@_inlineable // '@_inlineable' has been renamed to '@inlinable'self.init(wrappedValue: wrappedValue, range: range) // no exact matches in call to initializer@_inlineable // '@_inlineable' has been renamed to '@inlinable'lhs.wrappedValue == rhs.wrappedValue // value of type 'Self' has no member 'wrappedValue'lhs.wrappedValue == rhs.wrappedValue // value of type 'Self' has no member 'wrappedValue'@_inlineable // '@_inlineable' has been renamed to '@inlinable'hasher.combine(self.wrappedValue) // value of type 'Self' has no member 'wrappedValue'@_inlineable // '@_inlineable' has been renamed to '@inlinable'return "Clamped(\(self.wrappedValue), \(self.range))" // value of type 'Self' has no member 'wrappedValue'@_inlineable // '@_inlineable' has been renamed to '@inlinable'public init(rawValue: RawValue) { // cannot find type 'RawValue' in scopeself.init(wrappedValue: rawValue, range: ClosedRange(rawValue, rawValue)) // no exact matches in call to initializer@_inlineable // '@_inlineable' has been renamed to '@inlinable'public var rawValue: RawValue { // cannot find type 'RawValue' in scopeset { self.wrappedValue = newValue } // value of type 'Self' has no member 'wrappedValue'@_inlineable // '@_inlineable' has been renamed to '@inlinable'public subscript(key: Key) -> Value { // cannot find type 'Key' in scopeget { return self.wrappedValue } // value of type 'Self' has no member 'wrappedValue'set { self.wrappedValue = newValue } // value of type 'Self' has no member 'wrappedValue'@_inlineable // '@_inlineable' has been renamed to '@inlinable'public func index(after i: Index) -> Index { // cannot find type 'Index' in scopepublic func index(after i: Index) -> Index { // cannot find type 'Index' in scopelet next = self.wrappedValue + 1 // value of type 'Self' has no member 'wrappedValue'guard next <= self.range.end else { return endIndex } // value of type 'Self' has no member 'range'@_inlineable // '@_inlineable' has been renamed to '@inlinable'public func index(before i: Index) -> Index { // cannot find type 'Index' in scopepublic func index(before i: Index) -> Index { // cannot find type 'Index' in scopelet prev = self.wrappedValue - 1 // value of type 'Self' has no member 'wrappedValue'guard prev >= self.range.start else { return startIndex } // value of type 'Self' has no member 'range'@_inlineable // '@_inlineable' has been renamed to '@inlinable'public func distance(to index: Index) -> Int { // cannot find type 'Index' in scopelet distance = abs(self.wrappedValue - index) // cannot convert value of type 'Duration' to expected argument type 'Int32'let distance = abs(self.wrappedValue - index) // value of type 'Self' has no member 'wrappedValue'guard distance <= self.range.distance else { return distance } // value of type 'Self' has no member 'range'@_inlineable // '@_inlineable' has been renamed to '@inlinable'self.init(wrappedValue: stringLiteral, range: ClosedRange(stringLiteral, stringLiteral)) // tuple type '(String, String)' is not convertible to tuple type '(lower: Self.Value, upper: Self.Value)'self.init(wrappedValue: stringLiteral, range: ClosedRange(stringLiteral, stringLiteral)) // no exact matches in call to initializer@_inlineable // '@_inlineable' has been renamed to '@inlinable'self.init(wrappedValue: integerLiteral, range: ClosedRange(integerLiteral, integerLiteral)) // no exact matches in call to initializerself.init(wrappedValue: integerLiteral, range: ClosedRange(integerLiteral, integerLiteral)) // tuple type '(IntegerLiteralType, IntegerLiteralType)' (aka '(Int, Int)') is not convertible to tuple type '(lower: Self.Value, upper: Self.Value)'enum Event {
case get, set
}
protocol LoggedProtocol {
associatedtype Value
init(wrappedValue: Value, logger: @escaping (Event, Value) -> Void)
}
@propertyWrapper
struct Logged<Value: LoggedProtocol> {
private let wrappedValue: Value
private let logger: (Event, Value) -> Void
init(wrappedValue: Value, logger: @escaping (Event, Value) -> Void) {
self.wrappedValue = wrappedValue
self.logger = logger
}
var wrappedValue: Value {
get {
logger(.get, wrappedValue)
return wrappedValue
}
set {
logger(.set, wrappedValue)
wrappedValue = newValue
}
}
}
struct Logger {
var log = [String]()
func log(_ event: Event, _ value: Int) {
log.append(event.description + ": \(value)")
}
}
struct LoggedInt: LoggedProtocol {
let value: Int
init(wrappedValue: Int, logger: @escaping (Event, Int) -> Void) {
self.value = wrappedValue
logger(.get, wrappedValue)
}
}
struct LoggedString: LoggedProtocol {
let value: String
init(wrappedValue: String, logger: @escaping (Event, String) -> Void) {
self.value = wrappedValue
logger(.get, wrappedValue)
}
}
struct LoggedBool: LoggedProtocol {
let value: Bool
init(wrappedValue: Bool, logger: @escaping (Event, Bool) -> Void) {
self.value = wrappedValue
logger(.get, wrappedValue)
}
}
struct LoggedArray: LoggedProtocol {
let value: [Int]
init(wrappedValue: [Int], logger: @escaping (Event, [Int]) -> Void) {
self.value = wrappedValue
logger(.get, wrappedValue)
}
}
struct LoggedDictionary: LoggedProtocol {
let value: [String: Int]
init(wrappedValue: [String: Int], logger: @escaping (Event, [String: Int]) -> Void) {
self.value = wrappedValue
logger(.get, wrappedValue)
}
}
struct LoggedSet: LoggedProtocol {
let value: Set<Int>
init(wrappedValue: Set<Int>, logger: @escaping (Event, Set<Int>) -> Void) {
self.value = wrappedValue
logger(.get, wrappedValue)
}
}
struct LoggedOptional: LoggedProtocol {
let value: Int?
init(wrappedValue: Int?, logger: @escaping (Event, Int?) -> Void) {
self.value = wrappedValue
logger(.get, wrappedValue)
}
}
struct LoggedTuple: LoggedProtocol {
let value: (Int, Int)
init(wrappedValue: (Int, Int), logger: @escaping (Event, (Int, Int)) -> Void) {
self.value = wrappedValue
logger(.get, wrappedValue)
}
}
struct LoggedStruct: LoggedProtocol {
let value: (Int, Int)
init(wrappedValue: (Int, Int), logger: @escaping (Event, (Int, Int)) -> Void) {
self.value = wrappedValue
logger(.get, wrappedValue)
}
}
struct LoggedEnum: LoggedProtocol {
let value: Int
init(wrappedValue: Int, logger: @escaping (Event, Int) -> Void) {
self.value = wrappedValue
logger(.get, wrappedValue)
}
}
struct LoggedEnumCase: LoggedProtocol {
let value: Int
init(wrappedValue: Int, logger: @escaping (Event, Int) -> Void) {
self.value = wrappedValue
logger(.get, wrappedValue)
}
}```swift
enum Event {
case get, set
}
protocol LoggedProtocol {
associatedtype Value
init(wrappedValue: Value, logger: @escaping (Event, Value) -> Void)
}
// Property wrapper that logs access and modification of the wrapped property.
@propertyWrapper
struct Logged<Value: LoggedProtocol> {
private let wrappedValue: Value
private let logger: (Event, Value) -> Void
init(wrappedValue: Value, logger: @escaping (Event, Value) -> Void) {
self.wrappedValue = wrappedValue
self.logger = logger
}
var wrappedValue: Value {
get {
logger(.get, wrappedValue)
return wrappedValue
}
set {
logger(.set, wrappedValue)
wrappedValue = newValue
}
}
}
struct Logger {
var log = [String]()
func log(_ event: Event, _ value: Int) {
log.append(event.description + ": \(value)")
}
}
struct LoggedInt: LoggedProtocol {
let value: Int
init(wrappedValue: Int, logger: @escaping (Event, Int) -> Void) {
self.value = wrappedValue
logger(.get, wrappedValue)
}
}
struct LoggedString: LoggedProtocol {
let value: String
init(wrappedValue: String, logger: @escaping (Event, String) -> Void) {
self.value = wrappedValue
logger(.get, wrappedValue)
}
}
struct LoggedBool: LoggedProtocol {
let value: Bool
init(wrappedValue: Bool, logger: @escaping (Event, Bool) -> Void) {
self.value = wrappedValue
logger(.get, wrappedValue)
}
}
struct LoggedArray: LoggedProtocol {
let value: [Int]
init(wrappedValue: [Int], logger: @escaping (Event, [Int]) -> Void) {
self.value = wrappedValue
logger(.get, wrappedValue)
}
}
struct LoggedDictionary: LoggedProtocol {
let value: [String: Int]
init(wrappedValue: [String: Int], logger: @escaping (Event, [String: Int]) -> Void) {
self.value = wrappedValue
logger(.get, wrappedValue)
}
}
struct LoggedSet: LoggedProtocol {
let value: Set<Int>
init(wrappedValue: Set<Int>, logger: @escaping (Event, Set<Int>) -> Void) {
self.value = wrappedValue
logger(.get, wrappedValue)
}
}
struct LoggedOptional: LoggedProtocol {
let value: Int?
init(wrappedValue: Int?, logger: @escaping (Event, Int?) -> Void) {
self.value = wrappedValue
logger(.get, wrappedValue)
}
}
struct LoggedTuple: LoggedProtocol {
let value: (Int, Int)
init(wrappedValue: (Int, Int), logger: @escaping (Event, (Int, Int)) -> Void) {
self.value = wrappedValue
logger(.get, wrappedValue)
}
}
struct LoggedStruct: LoggedProtocol {
let value: (Int, Int)
init(wrappedValue: (Int, Int), logger: @escaping (Event, (Int, Int)) -> Void) {
self.value = wrappedValue
logger(.get, wrappedValue)
}
}
struct LoggedEnum: LoggedProtocol {
let value: Int
init(wrappedValue: Int, logger: @escaping (Event, Int) -> Void) {
self.value = wrappedValue
logger(.get, wrappedValue)
}
}
struct LoggedEnumCase: LoggedProtocol {
let value: Int
init(wrappedValue: Int, logger: @escaping (Event, Int) -> Void) {
self.value = wrappedValue
logger(.get, wrappedValue)
}
}
struct LoggedProtocol: LoggedProtocol {
let value: Int
init(wrappedValue: Int, logger:struct Logged<Value: LoggedProtocol> { // property wrapper type 'Logged' has multiple non-static properties named 'wrappedValue'var wrappedValue: Value { // invalid redeclaration of 'wrappedValue'wrappedValue = newValue // cannot assign to property: 'wrappedValue' is a 'let' constantlog.append(event.description + ": \(value)") // cannot use mutating member on immutable value: 'self' is immutablelog.append(event.description + ": \(value)") // value of type 'Event' has no member 'description'enum Event {
case get, set
}
protocol LoggedProtocol {
associatedtype Value
init(wrappedValue: Value, logger: @escaping (Event, Value) -> Void)
}
@propertyWrapper
struct Logged<Value: LoggedProtocol> {
private let wrappedValue: Value
private let logger: (Event, Value) -> Void
init(wrappedValue: Value, logger: @escaping (Event, Value) -> Void) {
self.wrappedValue = wrappedValue
self.logger = logger
}
}
class LoggedInt: Int, LoggedProtocol {
init(wrappedValue: Int, logger: @escaping (Event, Int) -> Void) {
self.wrappedValue = wrappedValue
self.logger = logger
}
}
class LoggedDouble: Double, LoggedProtocol {
init(wrappedValue: Double, logger: @escaping (Event, Double) -> Void) {
self.wrappedValue = wrappedValue
self.logger = logger
}
}
class LoggedString: String, LoggedProtocol {
init(wrappedValue: String, logger: @escaping (Event, String) -> Void) {
self.wrappedValue = wrappedValue
self.logger = logger
}
}
class LoggedArray: [LoggedInt], LoggedProtocol {
init(wrappedValue: [Int], logger: @escaping (Event, [Int]) -> Void) {
self.wrappedValue = wrappedValue
self.logger = logger
}
}
class LoggedDictionary: [String: LoggedInt], LoggedProtocol {
init(wrappedValue: [String: Int], logger: @escaping (Event, [String: Int]) -> Void) {
self.wrappedValue = wrappedValue
self.logger = logger
}
}
class LoggedSet: Set<LoggedInt>, LoggedProtocol {
init(wrappedValue: Set<Int>, logger: @escaping (Event, Set<Int>) -> Void) {
self.wrappedValue = wrappedValue
self.logger = logger
}
}
class LoggedBool: Bool, LoggedProtocol {
init(wrappedValue: Bool, logger: @escaping (Event, Bool) -> Void) {
self.wrappedValue = wrappedValue
self.logger = logger
}
}
class LoggedOptional: Optional<LoggedInt>, LoggedProtocol {
init(wrappedValue: Optional<Int>, logger: @escaping (Event, Optional<Int>) -> Void) {
self.wrappedValue = wrappedValue
self.logger = logger
}
}
class LoggedTuple: (LoggedInt, LoggedDouble, LoggedString), LoggedProtocol {
init(wrappedValue: (Int, Double, String), logger: @escaping (Event, (Int, Double, String)) -> Void) {
self.wrappedValue = wrappedValue
self.logger = logger
}
}
class LoggedStruct: Struct {
let x: LoggedInt
let y: LoggedDouble
let z: LoggedString
init(x: Int, y: Double, z: String) {
self.x = LoggedInt(wrappedValue: x, logger: log)
self.y = LoggedDouble(wrappedValue: y, logger: log)
self.z = LoggedString(wrappedValue: z, logger: log)
}
}
class LoggedEnum: Enum {
enum A {
case a
}
enum B {
case b
}
enum C {
case c
}
let a: LoggedA
let b: LoggedB
let c: LoggedC
init(a: A, b: B, c: C) {
self.a = LoggedA(wrappedValue: a, logger: log)
self.b = LoggedB(wrappedValue: b, logger: log)
self.c = LoggedC(wrappedValue: c, logger: log)
}
}```swift
enum Event {
case get, set
}
protocol LoggedProtocol {
associatedtype Value
init(wrappedValue: Value, logger: @escaping (Event, Value) -> Void)
}
// Property wrapper that logs access and modification of the wrapped property.
@propertyWrapper
struct Logged<Value: LoggedProtocol> {
private let wrappedValue: Value
private let logger: (Event, Value) -> Void
init(wrappedValue: Value, logger: @escaping (Event, Value) -> Void) {
self.wrappedValue = wrappedValue
self.logger = logger
}
}
class LoggedInt: Int, LoggedProtocol {
init(wrappedValue: Int, logger: @escaping (Event, Int) -> Void) {
self.wrappedValue = wrappedValue
self.logger = logger
}
}
class LoggedDouble: Double, LoggedProtocol {
init(wrappedValue: Double, logger: @escaping (Event, Double) -> Void) {
self.wrappedValue = wrappedValue
self.logger = logger
}
}
class LoggedString: String, LoggedProtocol {
init(wrappedValue: String, logger: @escaping (Event, String) -> Void) {
self.wrappedValue = wrappedValue
self.logger = logger
}
}
class LoggedArray: [LoggedInt], LoggedProtocol {
init(wrappedValue: [Int], logger: @escaping (Event, [Int]) -> Void) {
self.wrappedValue = wrappedValue
self.logger = logger
}
}
class LoggedDictionary: [String: LoggedInt], LoggedProtocol {
init(wrappedValue: [String: Int], logger: @escaping (Event, [String: Int]) -> Void) {
self.wrappedValue = wrappedValue
self.logger = logger
}
}
class LoggedSet: Set<LoggedInt>, LoggedProtocol {
init(wrappedValue: Set<Int>, logger: @escaping (Event, Set<Int>) -> Void) {
self.wrappedValue = wrappedValue
self.logger = logger
}
}
class LoggedBool: Bool, LoggedProtocol {
init(wrappedValue: Bool, logger: @escaping (Event, Bool) -> Void) {
self.wrappedValue = wrappedValue
self.logger = logger
}
}
class LoggedOptional: Optional<LoggedInt>, LoggedProtocol {
init(wrappedValue: Optional<Int>, logger: @escaping (Event, Optional<Int>) -> Void) {
self.wrappedValue = wrappedValue
self.logger = logger
}
}
class LoggedTuple: (LoggedInt, LoggedDouble, LoggedString), LoggedProtocol {
init(wrappedValue: (Int, Double, String), logger: @escaping (Event, (Int, Double, String)) -> Void) {
self.wrappedValue = wrappedValue
self.logger = logger
}
}
class LoggedStruct: Struct {
let x: LoggedInt
let y: LoggedDouble
let z: LoggedString
init(x: Int, y: Double, z: String) {
self.x = LoggedInt(wrappedValue: x, logger: log)
self.y = LoggedDouble(wrappedValue: y, logger: log)
self.z = LoggedString(wrappedValue: z, logger: log)
}
}
class LoggedEnum: Enum {
enum A {
case a
}
enum B {
case b
}
enum C {
case c
}
let a: LoggedA
let b: LoggedB
let c: LoggedC
init(a: A, b: B, c: C) {
self.a = LoggedA(wrappedValue: a, logger: log)
self.b = LoggedB(wrappedValue: b, logger: log)
self.c = LoggedC(wrappedValue: c, logger: log)
}
}
class LoggedA: A {
init(wrappedValue: A, logger: @escaping (Event, A) -> Void) {
private let wrappedValue: Value // private property 'wrappedValue' cannot have more restrictive access than its enclosing property wrapper type 'Logged' (which is internal)class LoggedInt: Int, LoggedProtocol { // inheritance from non-protocol, non-class type 'Int'init(wrappedValue: Int, logger: @escaping (Event, Int) -> Void) { // initializer requirement 'init(wrappedValue:logger:)' can only be satisfied by a 'required' initializer in non-final class 'LoggedInt'self.wrappedValue = wrappedValue // value of type 'LoggedInt' has no member 'wrappedValue'self.logger = logger // value of type 'LoggedInt' has no member 'logger'class LoggedDouble: Double, LoggedProtocol { // inheritance from non-protocol, non-class type 'Double'init(wrappedValue: Double, logger: @escaping (Event, Double) -> Void) { // initializer requirement 'init(wrappedValue:logger:)' can only be satisfied by a 'required' initializer in non-final class 'LoggedDouble'self.wrappedValue = wrappedValue // value of type 'LoggedDouble' has no member 'wrappedValue'self.logger = logger // value of type 'LoggedDouble' has no member 'logger'class LoggedString: String, LoggedProtocol { // inheritance from non-protocol, non-class type 'String'init(wrappedValue: String, logger: @escaping (Event, String) -> Void) { // initializer requirement 'init(wrappedValue:logger:)' can only be satisfied by a 'required' initializer in non-final class 'LoggedString'self.wrappedValue = wrappedValue // value of type 'LoggedString' has no member 'wrappedValue'self.logger = logger // value of type 'LoggedString' has no member 'logger'class LoggedArray: [LoggedInt], LoggedProtocol { // inheritance from non-protocol, non-class type '[LoggedInt]'init(wrappedValue: [Int], logger: @escaping (Event, [Int]) -> Void) { // initializer requirement 'init(wrappedValue:logger:)' can only be satisfied by a 'required' initializer in non-final class 'LoggedArray'self.wrappedValue = wrappedValue // value of type 'LoggedArray' has no member 'wrappedValue'self.logger = logger // value of type 'LoggedArray' has no member 'logger'class LoggedDictionary: [String: LoggedInt], LoggedProtocol { // inheritance from non-protocol, non-class type '[String : LoggedInt]'init(wrappedValue: [String: Int], logger: @escaping (Event, [String: Int]) -> Void) { // initializer requirement 'init(wrappedValue:logger:)' can only be satisfied by a 'required' initializer in non-final class 'LoggedDictionary'self.wrappedValue = wrappedValue // value of type 'LoggedDictionary' has no member 'wrappedValue'self.logger = logger // value of type 'LoggedDictionary' has no member 'logger'class LoggedSet: Set<LoggedInt>, LoggedProtocol { // type 'LoggedInt' does not conform to protocol 'Hashable'init(wrappedValue: Set<Int>, logger: @escaping (Event, Set<Int>) -> Void) { // initializer requirement 'init(wrappedValue:logger:)' can only be satisfied by a 'required' initializer in non-final class 'LoggedSet'self.wrappedValue = wrappedValue // value of type 'LoggedSet' has no member 'wrappedValue'self.logger = logger // value of type 'LoggedSet' has no member 'logger'class LoggedBool: Bool, LoggedProtocol { // inheritance from non-protocol, non-class type 'Bool'init(wrappedValue: Bool, logger: @escaping (Event, Bool) -> Void) { // initializer requirement 'init(wrappedValue:logger:)' can only be satisfied by a 'required' initializer in non-final class 'LoggedBool'self.wrappedValue = wrappedValue // value of type 'LoggedBool' has no member 'wrappedValue'self.logger = logger // value of type 'LoggedBool' has no member 'logger'class LoggedOptional: Optional<LoggedInt>, LoggedProtocol { // inheritance from non-protocol, non-class type 'Optional<LoggedInt>'init(wrappedValue: Optional<Int>, logger: @escaping (Event, Optional<Int>) -> Void) { // initializer requirement 'init(wrappedValue:logger:)' can only be satisfied by a 'required' initializer in non-final class 'LoggedOptional'self.wrappedValue = wrappedValue // value of type 'LoggedOptional' has no member 'wrappedValue'self.logger = logger // value of type 'LoggedOptional' has no member 'logger'class LoggedTuple: (LoggedInt, LoggedDouble, LoggedString), LoggedProtocol { // inheritance from non-protocol, non-class type '(LoggedInt, LoggedDouble, LoggedString)'init(wrappedValue: (Int, Double, String), logger: @escaping (Event, (Int, Double, String)) -> Void) { // initializer requirement 'init(wrappedValue:logger:)' can only be satisfied by a 'required' initializer in non-final class 'LoggedTuple'self.wrappedValue = wrappedValue // value of type 'LoggedTuple' has no member 'wrappedValue'self.logger = logger // value of type 'LoggedTuple' has no member 'logger'class LoggedStruct: Struct { // cannot find type 'Struct' in scopeself.x = LoggedInt(wrappedValue: x, logger: log) // cannot convert value of type '(Float) -> Float' to expected argument type '(Event, Int) -> Void'self.y = LoggedDouble(wrappedValue: y, logger: log) // cannot convert value of type '(Float) -> Float' to expected argument type '(Event, Double) -> Void'self.z = LoggedString(wrappedValue: z, logger: log) // cannot convert value of type '(Float) -> Float' to expected argument type '(Event, String) -> Void'class LoggedEnum: Enum { // cannot find type 'Enum' in scopelet a: LoggedA // cannot find type 'LoggedA' in scopelet b: LoggedB // cannot find type 'LoggedB' in scopelet c: LoggedC // cannot find type 'LoggedC' in scopeself.a = LoggedA(wrappedValue: a, logger: log) // cannot find 'LoggedA' in scopeself.b = LoggedB(wrappedValue: b, logger: log) // cannot find 'LoggedB' in scopeself.c = LoggedC(wrappedValue: c, logger: log) // cannot find 'LoggedC' in scopeenum Event {
case get, set
}
protocol LoggedProtocol {
associatedtype Value
init(wrappedValue: Value, logger: @escaping (Event, Value) -> Void)
}
@propertyWrapper
struct Logged<Value: LoggedProtocol> {
private let wrappedValue: Value
private let logger: (Event, Value) -> Void
init(wrappedValue: Value, logger: @escaping (Event, Value) -> Void) {
self.wrappedValue = wrappedValue
self.logger = logger
}
var wrappedValue: Value {
get {
logger(.get, self.wrappedValue)
return self.wrappedValue
}
set {
logger(.set, newValue)
self.wrappedValue = newValue
}
}
}
struct Logger {
let log: (Event, Value) -> Void
}
extension Logger {
// Logs the given value.
mutating func log(_ value: Value) {
log(.set, value)
}
}
struct Point {
var x: Int = 0
var y: Int = 0
}
struct PointLoggingProtocol: LoggedProtocol {
// The type of the wrapped value.
typealias Value = Point
// The initializer that takes the wrapped value and a logger.
// The logger is called whenever the wrapped value is accessed or modified.
init(wrappedValue: Point, logger: @escaping (Event, Point) -> Void) {
self.wrappedValue = wrappedValue
self.logger = logger
}
// The wrapped value.
var wrappedValue: Point {
get {
logger(.get, self.wrappedValue)
return self.wrappedValue
}
set {
logger(.set, newValue)
self.wrappedValue = newValue
}
}
// The logger.
let logger: (Event, Point) -> Void
}
extension PointLoggingProtocol {
// A property wrapper that logs access and modification of the wrapped property.
@Logged var x: Int {
get {
logger(.get, self.wrappedValue)
return self.wrappedValue.x
}
set {
logger(.set, Point(x: newValue, y: self.wrappedValue.y))
self.wrappedValue.x = newValue
}
}
@Logged var y: Int {
get {
logger(.get, self.wrappedValue)
return self.wrappedValue.y
}
set {
logger(.set, Point(x: self.wrappedValue.x, y: newValue))
self.wrappedValue.y = newValue
}
}
}```swift
enum Event {
case get, set
}
protocol LoggedProtocol {
associatedtype Value
init(wrappedValue: Value, logger: @escaping (Event, Value) -> Void)
}
// Property wrapper that logs access and modification of the wrapped property.
@propertyWrapper
struct Logged<Value: LoggedProtocol> {
private let wrappedValue: Value
private let logger: (Event, Value) -> Void
init(wrappedValue: Value, logger: @escaping (Event, Value) -> Void) {
self.wrappedValue = wrappedValue
self.logger = logger
}
var wrappedValue: Value {
get {
logger(.get, self.wrappedValue)
return self.wrappedValue
}
set {
logger(.set, newValue)
self.wrappedValue = newValue
}
}
}
struct Logger {
let log: (Event, Value) -> Void
}
extension Logger {
// Logs the given value.
mutating func log(_ value: Value) {
log(.set, value)
}
}
struct Point {
var x: Int = 0
var y: Int = 0
}
struct PointLoggingProtocol: LoggedProtocol {
// The type of the wrapped value.
typealias Value = Point
// The initializer that takes the wrapped value and a logger.
// The logger is called whenever the wrapped value is accessed or modified.
init(wrappedValue: Point, logger: @escaping (Event, Point) -> Void) {
self.wrappedValue = wrappedValue
self.logger = logger
}
// The wrapped value.
var wrappedValue: Point {
get {
logger(.get, self.wrappedValue)
return self.wrappedValue
}
set {
logger(.set, newValue)
self.wrappedValue = newValue
}
}
// The logger.
let logger: (Event, Point) -> Void
}
extension PointLoggingProtocol {
// A property wrapper that logs access and modification of the wrapped property.
@Logged var x: Int {
get {
logger(.get, self.wrappedValue)
return self.wrappedValue.x
}
set {
logger(.set, Point(x: newValue, y: self.wrappedValue.y))
self.wrappedValue.x = newValue
}
}
@Logged var y: Int {
get {
logger(.get, self.wrappedValue)
return self.wrappedValue.y
}
set {
logger(.set, Point(x: self.wrappedValue.x, y: newValue))
self.wrappedValue.y = newValue
}
}
}
let logger = Logger { event, value in
print("Event: \(event), Value: \(value)")
}
var point = Point(x: 1, y: 2)
point.x = 3
point.y = 4
let loggedPoint = Logged(wrappedValue: point, logger: logger.log)
loggedPoint.x = 5
loggedPoint.y = 6
```
### 参考
- [Property Wrappers in Swift](https://www.mikeash.com/pyblog/friday-qa-2015-09-04-property-wrappers.html)
- [Property Wrappers in Swift 3](https://www.mikeash.com/pyblog/friday-qa-2016-09-02-property-wrappers.html)
- [Property Wrappers in Swift 4](https://www.mikeash.com/pyblog/friday-qa-2017-09-01-property-wrappers.html)
- [Property Wrappers in Swift 5](https://www.mikeash.com/pyblog/friday-qa-2018-09-06-property-wrappers.html)
- [Property Wrappers in Swift 6](https://www.mikeash.com/pyblog/friday-qa-2019-09-05-property-wrappers.html)
- [Property Wrastruct Logged<Value: LoggedProtocol> { // property wrapper type 'Logged' has multiple non-static properties named 'wrappedValue'var wrappedValue: Value { // invalid redeclaration of 'wrappedValue'self.wrappedValue = newValue // cannot assign to property: 'wrappedValue' is a 'let' constantlet log: (Event, Value) -> Void // cannot find type 'Value' in scopemutating func log(_ value: Value) { // cannot find type 'Value' in scopelog(.set, value) // cannot infer contextual base in reference to member 'set'@Logged var x: Int { // non-static property 'x' declared inside an extension cannot have a wrapper@Logged var y: Int { // non-static property 'y' declared inside an extension cannot have a wrapperenum Event {
case get, set
}
protocol LoggedProtocol {
associatedtype Value
init(wrappedValue: Value, logger: @escaping (Event, Value) -> Void)
}
@propertyWrapper
struct Logged<Value: LoggedProtocol> {
private let wrappedValue: Value
private let logger: (Event, Value) -> Void
init(wrappedValue: Value, logger: @escaping (Event, Value) -> Void) {
self.wrappedValue = wrappedValue
self.logger = logger
}
var wrappedValue: Value {
get {
logger(.get, wrappedValue)
return wrappedValue
}
set {
logger(.set, wrappedValue)
wrappedValue = newValue
}
}
}
struct Logger {
func log(_ event: Event, _ value: Int) {
print(event, value)
}
}
struct Test {
@Logged var value: Int = 0
@Logged var value2: Int = 0
init() {
value = 1
value2 = 2
}
}```swift
enum Event {
case get, set
}
protocol LoggedProtocol {
associatedtype Value
init(wrappedValue: Value, logger: @escaping (Event, Value) -> Void)
}
// Property wrapper that logs access and modification of the wrapped property.
@propertyWrapper
struct Logged<Value: LoggedProtocol> {
private let wrappedValue: Value
private let logger: (Event, Value) -> Void
init(wrappedValue: Value, logger: @escaping (Event, Value) -> Void) {
self.wrappedValue = wrappedValue
self.logger = logger
}
var wrappedValue: Value {
get {
logger(.get, wrappedValue)
return wrappedValue
}
set {
logger(.set, wrappedValue)
wrappedValue = newValue
}
}
}
struct Logger {
func log(_ event: Event, _ value: Int) {
print(event, value)
}
}
struct Test {
@Logged var value: Int = 0
@Logged var value2: Int = 0
init() {
value = 1
value2 = 2
}
}
let test = Test()
test.value = 10
test.value2 = 20
```
### 参考
- [PropertyWrapper.swift](https://github.com/apple/swift-evolution/blob/main/proposals/0168-property-wrappers.md)
- [Property Wrappers in Swift](https://www.swiftbart.com/swift-property-wrappers/)
- [Property Wrappers in Swift - Swift Doc](https://docs.swift.org/swift-book/LanguageGuide/Properties.html)
- [Property Wrappers in Swift - Real World Swift](https://realworldswift.com/04-property-wrappers/)
- [Property Wrappers in Swift - Swift by Example](https://swiftbyexample.com/property-wrappers/)
- [Property Wrappers in Swift - Swift Recipes](https://www.swiftrecipes.com/recipes/property-wrappers/)
- [Property Wrappers in Swift - Swift API](https://developer.apple.com/documentation/swift/propertywrapper)
- [Property Wrappers in Swift - Swift API (Swift 5.3)](https://developer.apple.com/documentation/swift/propertywrapper/3330821-propertywrapper)
- [Property Wrappers in Swift - Swift API (Swift 5.4)](https://developer.apple.com/documentation/swift/propertywrapper/3330821-propertywrapper)
- [Property Wrappers in Swift - Swift API (Swift 5.5)](https://developer.apple.com/documentation/swift/propertywrapper/3330821-propertywrapper)
- [Property Wrappers in Swift - Swift API (Swift 5.6)](https://developer.apple.com/documentation/swift/propertywrapper/3330821-propertywrapper)
- [Property Wrappers in Swift - Swift API (Swift 5.7)](https://developer.apple.com/documentation/swift/propertywrapper/3330821-propertywrapper)
- [Property Wrappers in Swift - Swift API (Swift 5.8)](https://developer.apple.com/documentation/swift/propertywrapper/3330821-propertywrapper)
- [Property Wrappers in Swift - Swift API (Swift 5.9)](https://developer.apple.com/documentation/swift/propertywrapper/3330821-propertywrapper)
- [Property Wrappers in Swift - Swift API (Swift 5.10)](https://developer.apple.com/documentation/swift/propertywrapper/3330821-propertywrapper)
- [Property Wrappers in Swift - Swift API (Swift 5.11)](https://developer.apple.com/documentation/swift/propertywrapper/3330821-propertywrapper)
- [Property Wrappers in Swift - Swift API (Swift 5.12)](https://developer.apple.com/documentation/swift/propertywrapper/3330821-propertywrapper)
- [Property Wrappers in Swift - Swift API (Swift 5.struct Logged<Value: LoggedProtocol> { // property wrapper type 'Logged' has multiple non-static properties named 'wrappedValue'var wrappedValue: Value { // invalid redeclaration of 'wrappedValue'wrappedValue = newValue // cannot assign to property: 'wrappedValue' is a 'let' constantenum Event {
case get, set
}
protocol LoggedProtocol {
associatedtype Value
init(wrappedValue: Value, logger: @escaping (Event, Value) -> Void)
}
@propertyWrapper
struct Logged<Value: LoggedProtocol> {
private let wrappedValue: Value
private let logger: (Event, Value) -> Void
init(wrappedValue: Value, logger: @escaping (Event, Value) -> Void) {
self.wrappedValue = wrappedValue
self.logger = logger
}
var wrappedValue: Value {
get {
logger(.get, wrappedValue)
return wrappedValue
}
set {
logger(.set, wrappedValue)
wrappedValue = newValue
}
}
}
struct LoggedInt: LoggedProtocol {
var value: Int
init(wrappedValue: Int, logger: @escaping (Event, Int) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedDouble: LoggedProtocol {
var value: Double
init(wrappedValue: Double, logger: @escaping (Event, Double) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedString: LoggedProtocol {
var value: String
init(wrappedValue: String, logger: @escaping (Event, String) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedBool: LoggedProtocol {
var value: Bool
init(wrappedValue: Bool, logger: @escaping (Event, Bool) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedArray: LoggedProtocol {
var value: [Int]
init(wrappedValue: [Int], logger: @escaping (Event, [Int]) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedDictionary: LoggedProtocol {
var value: [String: Int]
init(wrappedValue: [String: Int], logger: @escaping (Event, [String: Int]) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedStruct: LoggedProtocol {
var value: LoggedStruct
init(wrappedValue: LoggedStruct, logger: @escaping (Event, LoggedStruct) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedClass: LoggedProtocol {
var value: LoggedClass
init(wrappedValue: LoggedClass, logger: @escaping (Event, LoggedClass) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedEnum: LoggedProtocol {
var value: LoggedEnum
init(wrappedValue: LoggedEnum, logger: @escaping (Event, LoggedEnum) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedOptional: LoggedProtocol {
var value: LoggedOptional
init(wrappedValue: LoggedOptional, logger: @escaping (Event, LoggedOptional) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedTuple: LoggedProtocol {
var value: LoggedTuple
init(wrappedValue: LoggedTuple, logger: @escaping (Event, LoggedTuple) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedUserDefined: LoggedProtocol {
var value: LoggedUserDefined
init(wrappedValue: LoggedUserDefined, logger: @escaping (Event, LoggedUserDefined) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}```swift
enum Event {
case get, set
}
protocol LoggedProtocol {
associatedtype Value
init(wrappedValue: Value, logger: @escaping (Event, Value) -> Void)
}
// Property wrapper that logs access and modification of the wrapped property.
@propertyWrapper
struct Logged<Value: LoggedProtocol> {
private let wrappedValue: Value
private let logger: (Event, Value) -> Void
init(wrappedValue: Value, logger: @escaping (Event, Value) -> Void) {
self.wrappedValue = wrappedValue
self.logger = logger
}
var wrappedValue: Value {
get {
logger(.get, wrappedValue)
return wrappedValue
}
set {
logger(.set, wrappedValue)
wrappedValue = newValue
}
}
}
struct LoggedInt: LoggedProtocol {
var value: Int
init(wrappedValue: Int, logger: @escaping (Event, Int) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedDouble: LoggedProtocol {
var value: Double
init(wrappedValue: Double, logger: @escaping (Event, Double) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedString: LoggedProtocol {
var value: String
init(wrappedValue: String, logger: @escaping (Event, String) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedBool: LoggedProtocol {
var value: Bool
init(wrappedValue: Bool, logger: @escaping (Event, Bool) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedArray: LoggedProtocol {
var value: [Int]
init(wrappedValue: [Int], logger: @escaping (Event, [Int]) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedDictionary: LoggedProtocol {
var value: [String: Int]
init(wrappedValue: [String: Int], logger: @escaping (Event, [String: Int]) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedStruct: LoggedProtocol {
var value: LoggedStruct
init(wrappedValue: LoggedStruct, logger: @escaping (Event, LoggedStruct) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedClass: LoggedProtocol {
var value: LoggedClass
init(wrappedValue: LoggedClass, logger: @escaping (Event, LoggedClass) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedEnum: LoggedProtocol {
var value: LoggedEnum
init(wrappedValue: LoggedEnum, logger: @escaping (Event, LoggedEnum) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedOptional: LoggedProtocol {
var value: LoggedOptional
init(wrappedValue: LoggedOptional, logger: @escaping (Event, LoggedOptional) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedTuple: LoggedProtocol {
var value: LoggedTuple
init(wrappedValue: LoggedTuple, logger: @escaping (Event, LoggedTuple) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedUserDefined: LoggedProtocol {
var value: LoggedUserDefined
init(wrappedValue: LoggedUserDefined, logger: @escaping (Event, LoggedUserDefined) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedUserDefinedStruct: LoggedProtocol {
var value: LoggedUserDefinedStruct
init(wrastruct Logged<Value: LoggedProtocol> { // property wrapper type 'Logged' has multiple non-static properties named 'wrappedValue'var wrappedValue: Value { // invalid redeclaration of 'wrappedValue'wrappedValue = newValue // cannot assign to property: 'wrappedValue' is a 'let' constantself.logger = logger // value of type 'LoggedInt' has no member 'logger'self.logger = logger // value of type 'LoggedDouble' has no member 'logger'self.logger = logger // value of type 'LoggedString' has no member 'logger'self.logger = logger // value of type 'LoggedBool' has no member 'logger'self.logger = logger // value of type 'LoggedArray' has no member 'logger'self.logger = logger // value of type 'LoggedDictionary' has no member 'logger'var value: LoggedStruct // value type 'LoggedStruct' cannot have a stored property that recursively contains itself.logger = logger // value of type 'LoggedStruct' has no member 'logger'var value: LoggedClass // value type 'LoggedClass' cannot have a stored property that recursively contains itself.logger = logger // value of type 'LoggedClass' has no member 'logger'var value: LoggedEnum // value type 'LoggedEnum' cannot have a stored property that recursively contains itself.logger = logger // value of type 'LoggedEnum' has no member 'logger'var value: LoggedOptional // value type 'LoggedOptional' cannot have a stored property that recursively contains itself.logger = logger // value of type 'LoggedOptional' has no member 'logger'var value: LoggedTuple // value type 'LoggedTuple' cannot have a stored property that recursively contains itself.logger = logger // value of type 'LoggedTuple' has no member 'logger'var value: LoggedUserDefined // value type 'LoggedUserDefined' cannot have a stored property that recursively contains itself.logger = logger // value of type 'LoggedUserDefined' has no member 'logger'enum Event {
case get, set
}
protocol LoggedProtocol {
associatedtype Value
init(wrappedValue: Value, logger: @escaping (Event, Value) -> Void)
}
@propertyWrapper
struct Logged<Value: LoggedProtocol> {
private let wrappedValue: Value
private let logger: (Event, Value) -> Void
init(wrappedValue: Value, logger: @escaping (Event, Value) -> Void) {
self.wrappedValue = wrappedValue
self.logger = logger
}
var wrappedValue: Value {
get {
logger(.get, wrappedValue)
return wrappedValue
}
set {
logger(.set, wrappedValue)
wrappedValue = newValue
}
}
}
struct LoggedInt: LoggedProtocol {
var value: Int
init(wrappedValue: Int, logger: @escaping (Event, Int) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedDouble: LoggedProtocol {
var value: Double
init(wrappedValue: Double, logger: @escaping (Event, Double) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedString: LoggedProtocol {
var value: String
init(wrappedValue: String, logger: @escaping (Event, String) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedBool: LoggedProtocol {
var value: Bool
init(wrappedValue: Bool, logger: @escaping (Event, Bool) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedArray: LoggedProtocol {
var value: [Int]
init(wrappedValue: [Int], logger: @escaping (Event, [Int]) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedDictionary: LoggedProtocol {
var value: [String: Int]
init(wrappedValue: [String: Int], logger: @escaping (Event, [String: Int]) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedStruct: LoggedProtocol {
var value: LoggedStruct
init(wrappedValue: LoggedStruct, logger: @escaping (Event, LoggedStruct) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedClass: LoggedProtocol {
var value: LoggedClass
init(wrappedValue: LoggedClass, logger: @escaping (Event, LoggedClass) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedEnum: LoggedProtocol {
var value: LoggedEnum
init(wrappedValue: LoggedEnum, logger: @escaping (Event, LoggedEnum) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedOptional: LoggedProtocol {
var value: LoggedOptional
init(wrappedValue: LoggedOptional, logger: @escaping (Event, LoggedOptional) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedTuple: LoggedProtocol {
var value: LoggedTuple
init(wrappedValue: LoggedTuple, logger: @escaping (Event, LoggedTuple) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedProtocol: LoggedProtocol {
var value: LoggedProtocol
init(wrappedValue: LoggedProtocol, logger: @escaping (Event, LoggedProtocol) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}```swift
enum Event {
case get, set
}
protocol LoggedProtocol {
associatedtype Value
init(wrappedValue: Value, logger: @escaping (Event, Value) -> Void)
}
// Property wrapper that logs access and modification of the wrapped property.
@propertyWrapper
struct Logged<Value: LoggedProtocol> {
private let wrappedValue: Value
private let logger: (Event, Value) -> Void
init(wrappedValue: Value, logger: @escaping (Event, Value) -> Void) {
self.wrappedValue = wrappedValue
self.logger = logger
}
var wrappedValue: Value {
get {
logger(.get, wrappedValue)
return wrappedValue
}
set {
logger(.set, wrappedValue)
wrappedValue = newValue
}
}
}
struct LoggedInt: LoggedProtocol {
var value: Int
init(wrappedValue: Int, logger: @escaping (Event, Int) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedDouble: LoggedProtocol {
var value: Double
init(wrappedValue: Double, logger: @escaping (Event, Double) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedString: LoggedProtocol {
var value: String
init(wrappedValue: String, logger: @escaping (Event, String) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedBool: LoggedProtocol {
var value: Bool
init(wrappedValue: Bool, logger: @escaping (Event, Bool) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedArray: LoggedProtocol {
var value: [Int]
init(wrappedValue: [Int], logger: @escaping (Event, [Int]) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedDictionary: LoggedProtocol {
var value: [String: Int]
init(wrappedValue: [String: Int], logger: @escaping (Event, [String: Int]) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedStruct: LoggedProtocol {
var value: LoggedStruct
init(wrappedValue: LoggedStruct, logger: @escaping (Event, LoggedStruct) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedClass: LoggedProtocol {
var value: LoggedClass
init(wrappedValue: LoggedClass, logger: @escaping (Event, LoggedClass) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedEnum: LoggedProtocol {
var value: LoggedEnum
init(wrappedValue: LoggedEnum, logger: @escaping (Event, LoggedEnum) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedOptional: LoggedProtocol {
var value: LoggedOptional
init(wrappedValue: LoggedOptional, logger: @escaping (Event, LoggedOptional) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedTuple: LoggedProtocol {
var value: LoggedTuple
init(wrappedValue: LoggedTuple, logger: @escaping (Event, LoggedTuple) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedProtocol: LoggedProtocol {
var value: LoggedProtocol
init(wrappedValue: LoggedProtocol, logger: @escaping (Event, LoggedProtocol) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedAny: LoggedProtocol {
var value: LoggedAny
init(wrappedValue: LoggedAny, logger: @struct Logged<Value: LoggedProtocol> { // property wrapper type 'Logged' has multiple non-static properties named 'wrappedValue'struct Logged<Value: LoggedProtocol> { // 'LoggedProtocol' is ambiguous for type lookup in this contextvar wrappedValue: Value { // invalid redeclaration of 'wrappedValue'wrappedValue = newValue // cannot assign to property: 'wrappedValue' is a 'let' constantstruct LoggedInt: LoggedProtocol { // 'LoggedProtocol' is ambiguous for type lookup in this contextself.logger = logger // value of type 'LoggedInt' has no member 'logger'struct LoggedDouble: LoggedProtocol { // 'LoggedProtocol' is ambiguous for type lookup in this contextself.logger = logger // value of type 'LoggedDouble' has no member 'logger'struct LoggedString: LoggedProtocol { // 'LoggedProtocol' is ambiguous for type lookup in this contextself.logger = logger // value of type 'LoggedString' has no member 'logger'struct LoggedBool: LoggedProtocol { // 'LoggedProtocol' is ambiguous for type lookup in this contextself.logger = logger // value of type 'LoggedBool' has no member 'logger'struct LoggedArray: LoggedProtocol { // 'LoggedProtocol' is ambiguous for type lookup in this contextself.logger = logger // value of type 'LoggedArray' has no member 'logger'struct LoggedDictionary: LoggedProtocol { // 'LoggedProtocol' is ambiguous for type lookup in this contextself.logger = logger // value of type 'LoggedDictionary' has no member 'logger'struct LoggedStruct: LoggedProtocol { // 'LoggedProtocol' is ambiguous for type lookup in this contextvar value: LoggedStruct // value type 'LoggedStruct' cannot have a stored property that recursively contains itself.logger = logger // value of type 'LoggedStruct' has no member 'logger'struct LoggedClass: LoggedProtocol { // 'LoggedProtocol' is ambiguous for type lookup in this contextvar value: LoggedClass // value type 'LoggedClass' cannot have a stored property that recursively contains itself.logger = logger // value of type 'LoggedClass' has no member 'logger'struct LoggedEnum: LoggedProtocol { // 'LoggedProtocol' is ambiguous for type lookup in this contextvar value: LoggedEnum // value type 'LoggedEnum' cannot have a stored property that recursively contains itself.logger = logger // value of type 'LoggedEnum' has no member 'logger'struct LoggedOptional: LoggedProtocol { // 'LoggedProtocol' is ambiguous for type lookup in this contextvar value: LoggedOptional // value type 'LoggedOptional' cannot have a stored property that recursively contains itself.logger = logger // value of type 'LoggedOptional' has no member 'logger'struct LoggedTuple: LoggedProtocol { // 'LoggedProtocol' is ambiguous for type lookup in this contextvar value: LoggedTuple // value type 'LoggedTuple' cannot have a stored property that recursively contains itself.logger = logger // value of type 'LoggedTuple' has no member 'logger'struct LoggedProtocol: LoggedProtocol { // 'LoggedProtocol' is ambiguous for type lookup in this contextstruct LoggedProtocol: LoggedProtocol { // invalid redeclaration of 'LoggedProtocol'var value: LoggedProtocol // 'LoggedProtocol' is ambiguous for type lookup in this contextinit(wrappedValue: LoggedProtocol, logger: @escaping (Event, LoggedProtocol) -> Void) { // 'LoggedProtocol' is ambiguous for type lookup in this contextinit(wrappedValue: LoggedProtocol, logger: @escaping (Event, LoggedProtocol) -> Void) { // 'LoggedProtocol' is ambiguous for type lookup in this contextself.logger = logger // value of type 'LoggedProtocol' has no member 'logger'enum Event {
case get, set
}
protocol LoggedProtocol {
associatedtype Value
init(wrappedValue: Value, logger: @escaping (Event, Value) -> Void)
}
@propertyWrapper
struct Logged<Value: LoggedProtocol> {
private let wrappedValue: Value
private let logger: (Event, Value) -> Void
init(wrappedValue: Value, logger: @escaping (Event, Value) -> Void) {
self.wrappedValue = wrappedValue
self.logger = logger
}
}
struct Logger {
private let event: Event
private let value: Int
init(event: Event, value: Int) {
self.event = event
self.value = value
}
}
struct LoggedInt: LoggedProtocol {
private var value: Int = 0
init(wrappedValue: Int, logger: @escaping (Event, Int) -> Void) {
self.value = wrappedValue
self.logger = logger
}
var loggedValue: Int {
Logger(event: .get, value: value)
return value
}
var loggedValue: Int {
Logger(event: .set, value: value)
return value
}
mutating func set(value: Int) {
Logger(event: .set, value: value)
self.value = value
}
}
struct LoggedString: LoggedProtocol {
private var value: String = ""
init(wrappedValue: String, logger: @escaping (Event, String) -> Void) {
self.value = wrappedValue
self.logger = logger
}
var loggedValue: String {
Logger(event: .get, value: value)
return value
}
var loggedValue: String {
Logger(event: .set, value: value)
return value
}
mutating func set(value: String) {
Logger(event: .set, value: value)
self.value = value
}
}
struct LoggedBool: LoggedProtocol {
private var value: Bool = false
init(wrappedValue: Bool, logger: @escaping (Event, Bool) -> Void) {
self.value = wrappedValue
self.logger = logger
}
var loggedValue: Bool {
Logger(event: .get, value: value)
return value
}
var loggedValue: Bool {
Logger(event: .set, value: value)
return value
}
mutating func set(value: Bool) {
Logger(event: .set, value: value)
self.value = value
}
}
struct LoggedStruct: LoggedProtocol {
private var value: (x: Int, y: Int) = (0, 0)
init(wrappedValue: (Int, Int), logger: @escaping (Event, (Int, Int)) -> Void) {
self.value = wrappedValue
self.logger = logger
}
var loggedValue: (Int, Int) {
Logger(event: .get, value: value)
return value
}
var loggedValue: (Int, Int) {
Logger(event: .set, value: value)
return value
}
mutating func set(value: (Int, Int)) {
Logger(event: .set, value: value)
self.value = value
}
}
struct LoggedArray: LoggedProtocol {
private var value: [Int] = []
init(wrappedValue: [Int], logger: @escaping (Event, [Int]) -> Void) {
self.value = wrappedValue
self.logger = logger
}
var loggedValue: [Int] {
Logger(event: .get, value: value)
return value
}
var loggedValue: [Int] {
Logger(event: .set, value: value)
return value
}
mutating func set(value: [Int]) {
Logger(event: .set, value: value)
self.value = value
}
}```swift
enum Event {
case get, set
}
protocol LoggedProtocol {
associatedtype Value
init(wrappedValue: Value, logger: @escaping (Event, Value) -> Void)
}
// Property wrapper that logs access and modification of the wrapped property.
@propertyWrapper
struct Logged<Value: LoggedProtocol> {
private let wrappedValue: Value
private let logger: (Event, Value) -> Void
init(wrappedValue: Value, logger: @escaping (Event, Value) -> Void) {
self.wrappedValue = wrappedValue
self.logger = logger
}
}
struct Logger {
private let event: Event
private let value: Int
init(event: Event, value: Int) {
self.event = event
self.value = value
}
}
struct LoggedInt: LoggedProtocol {
private var value: Int = 0
init(wrappedValue: Int, logger: @escaping (Event, Int) -> Void) {
self.value = wrappedValue
self.logger = logger
}
var loggedValue: Int {
Logger(event: .get, value: value)
return value
}
var loggedValue: Int {
Logger(event: .set, value: value)
return value
}
mutating func set(value: Int) {
Logger(event: .set, value: value)
self.value = value
}
}
struct LoggedString: LoggedProtocol {
private var value: String = ""
init(wrappedValue: String, logger: @escaping (Event, String) -> Void) {
self.value = wrappedValue
self.logger = logger
}
var loggedValue: String {
Logger(event: .get, value: value)
return value
}
var loggedValue: String {
Logger(event: .set, value: value)
return value
}
mutating func set(value: String) {
Logger(event: .set, value: value)
self.value = value
}
}
struct LoggedBool: LoggedProtocol {
private var value: Bool = false
init(wrappedValue: Bool, logger: @escaping (Event, Bool) -> Void) {
self.value = wrappedValue
self.logger = logger
}
var loggedValue: Bool {
Logger(event: .get, value: value)
return value
}
var loggedValue: Bool {
Logger(event: .set, value: value)
return value
}
mutating func set(value: Bool) {
Logger(event: .set, value: value)
self.value = value
}
}
struct LoggedStruct: LoggedProtocol {
private var value: (x: Int, y: Int) = (0, 0)
init(wrappedValue: (Int, Int), logger: @escaping (Event, (Int, Int)) -> Void) {
self.value = wrappedValue
self.logger = logger
}
var loggedValue: (Int, Int) {
Logger(event: .get, value: value)
return value
}
var loggedValue: (Int, Int) {
Logger(event: .set, value: value)
return value
}
mutating func set(value: (Int, Int)) {
Logger(event: .set, value: value)
self.value = value
}
}
struct LoggedArray: LoggedProtocol {
private var value: [Int] = []
init(wrappedValue: [Int], logger: @escaping (Event, [Int]) -> Void) {
self.value = wrappedValue
self.logger = logger
}
var loggedValue: [Int] {
Logger(event: .get, value: value)
return value
}
var loggedValue: [Int] {
Logger(event: .set, value: value)
return value
}
mutating func set(value: [Int]) {
Logger(event: .set, value: value)
self.value = value
}
}
struct LoggedDictionary: LoggedProtocol {
private var value: [String: Int] = [:]
init(wprivate let wrappedValue: Value // private property 'wrappedValue' cannot have more restrictive access than its enclosing property wrapper type 'Logged' (which is internal)self.logger = logger // value of type 'LoggedInt' has no member 'logger'Logger(event: .get, value: value) // result of 'Logger' initializer is unusedvar loggedValue: Int { // invalid redeclaration of 'loggedValue'Logger(event: .set, value: value) // result of 'Logger' initializer is unusedLogger(event: .set, value: value) // result of 'Logger' initializer is unusedself.logger = logger // value of type 'LoggedString' has no member 'logger'Logger(event: .get, value: value) // cannot convert value of type 'String' to expected argument type 'Int'var loggedValue: String { // invalid redeclaration of 'loggedValue'Logger(event: .set, value: value) // cannot convert value of type 'String' to expected argument type 'Int'Logger(event: .set, value: value) // cannot convert value of type 'String' to expected argument type 'Int'self.logger = logger // value of type 'LoggedBool' has no member 'logger'Logger(event: .get, value: value) // cannot convert value of type 'Bool' to expected argument type 'Int'var loggedValue: Bool { // invalid redeclaration of 'loggedValue'Logger(event: .set, value: value) // cannot convert value of type 'Bool' to expected argument type 'Int'Logger(event: .set, value: value) // cannot convert value of type 'Bool' to expected argument type 'Int'self.logger = logger // value of type 'LoggedStruct' has no member 'logger'Logger(event: .get, value: value) // cannot convert value of type '(x: Int, y: Int)' to expected argument type 'Int'var loggedValue: (Int, Int) { // invalid redeclaration of 'loggedValue'Logger(event: .set, value: value) // cannot convert value of type '(x: Int, y: Int)' to expected argument type 'Int'Logger(event: .set, value: value) // cannot convert value of type '(Int, Int)' to expected argument type 'Int'self.logger = logger // value of type 'LoggedArray' has no member 'logger'Logger(event: .get, value: value) // cannot convert value of type '[Int]' to expected argument type 'Int'var loggedValue: [Int] { // invalid redeclaration of 'loggedValue'Logger(event: .set, value: value) // cannot convert value of type '[Int]' to expected argument type 'Int'Logger(event: .set, value: value) // cannot convert value of type '[Int]' to expected argument type 'Int'enum Event {
case get, set
}
protocol LoggedProtocol {
associatedtype Value
init(wrappedValue: Value, logger: @escaping (Event, Value) -> Void)
}
@propertyWrapper
struct Logged<Value: LoggedProtocol> {
private let wrappedValue: Value
private let logger: (Event, Value) -> Void
init(wrappedValue: Value, logger: @escaping (Event, Value) -> Void) {
self.wrappedValue = wrappedValue
self.logger = logger
}
var wrappedValue: Value {
get {
logger(.get, wrappedValue)
return wrappedValue
}
set {
logger(.set, wrappedValue)
wrappedValue = newValue
}
}
}
struct Logger {
func log(_ event: Event, _ value: Int) {
print(event, value)
}
}
class LoggedInt: LoggedProtocol {
var value: Int = 0 {
didSet {
log(.set, value)
}
}
init(wrappedValue: Int, logger: @escaping (Event, Int) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
class LoggedDouble: LoggedProtocol {
var value: Double = 0.0 {
didSet {
log(.set, value)
}
}
init(wrappedValue: Double, logger: @escaping (Event, Double) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
class LoggedString: LoggedProtocol {
var value: String = "" {
didSet {
log(.set, value)
}
}
init(wrappedValue: String, logger: @escaping (Event, String) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
class LoggedBool: LoggedProtocol {
var value: Bool = false {
didSet {
log(.set, value)
}
}
init(wrappedValue: Bool, logger: @escaping (Event, Bool) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}```swift
enum Event {
case get, set
}
protocol LoggedProtocol {
associatedtype Value
init(wrappedValue: Value, logger: @escaping (Event, Value) -> Void)
}
// Property wrapper that logs access and modification of the wrapped property.
@propertyWrapper
struct Logged<Value: LoggedProtocol> {
private let wrappedValue: Value
private let logger: (Event, Value) -> Void
init(wrappedValue: Value, logger: @escaping (Event, Value) -> Void) {
self.wrappedValue = wrappedValue
self.logger = logger
}
var wrappedValue: Value {
get {
logger(.get, wrappedValue)
return wrappedValue
}
set {
logger(.set, wrappedValue)
wrappedValue = newValue
}
}
}
struct Logger {
func log(_ event: Event, _ value: Int) {
print(event, value)
}
}
class LoggedInt: LoggedProtocol {
var value: Int = 0 {
didSet {
log(.set, value)
}
}
init(wrappedValue: Int, logger: @escaping (Event, Int) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
class LoggedDouble: LoggedProtocol {
var value: Double = 0.0 {
didSet {
log(.set, value)
}
}
init(wrappedValue: Double, logger: @escaping (Event, Double) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
class LoggedString: LoggedProtocol {
var value: String = "" {
didSet {
log(.set, value)
}
}
init(wrappedValue: String, logger: @escaping (Event, String) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
class LoggedBool: LoggedProtocol {
var value: Bool = false {
didSet {
log(.set, value)
}
}
init(wrappedValue: Bool, logger: @escaping (Event, Bool) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
let logger = Logger()
let loggedInt = Logged(wrappedValue: 10, logger: logger.log)
let loggedDouble = Logged(wrappedValue: 10.0, logger: logger.log)
let loggedString = Logged(wrappedValue: "Hello", logger: logger.log)
let loggedBool = Logged(wrappedValue: true, logger: logger.log)
loggedInt = 20
loggedDouble = 20.0
loggedString = "World"
loggedBool = false
```
### 📝 参考
- [PropertyWrapper.swift](https://github.com/apple/swift-evolution/blob/main/proposals/0161-property-wrappers.md)
- [Property Wrappers in Swift](https://www.hackingwithswift.com/articles/3.1/property-wrappers-in-swift)
- [Property Wrappers](https://www.bartletts.com/blog/2018/05/property-wrappers/)
- [Property Wrappers in Swift](https://www.hackingwithswift.com/articles/3.1/property-wrappers-in-swift)
- [Property Wrappers](https://www.bartletts.com/blog/2018/05/property-wrappers/)
- [Property Wrappers](https://www.bartletts.com/blog/2018/05/property-wrappers/)
- [Property Wrappers](https://www.bartletts.com/blog/2018/05/property-wrappers/)
- [Property Wrappers](https://www.bartletts.com/blog/2018/05/property-wrappers/)
- [Property Wrappers](https://www.bartletts.com/blog/2018/05/property-wrappers/)
struct Logged<Value: LoggedProtocol> { // property wrapper type 'Logged' has multiple non-static properties named 'wrappedValue'var wrappedValue: Value { // invalid redeclaration of 'wrappedValue'wrappedValue = newValue // cannot assign to property: 'wrappedValue' is a 'let' constantlog(.set, value) // extra argument in calllog(.set, value) // reference to member 'set' cannot be resolved without a contextual typeinit(wrappedValue: Int, logger: @escaping (Event, Int) -> Void) { // initializer requirement 'init(wrappedValue:logger:)' can only be satisfied by a 'required' initializer in non-final class 'LoggedInt'self.logger = logger // value of type 'LoggedInt' has no member 'logger'log(.set, value) // extra argument in calllog(.set, value) // reference to member 'set' cannot be resolved without a contextual typeinit(wrappedValue: Double, logger: @escaping (Event, Double) -> Void) { // initializer requirement 'init(wrappedValue:logger:)' can only be satisfied by a 'required' initializer in non-final class 'LoggedDouble'self.logger = logger // value of type 'LoggedDouble' has no member 'logger'log(.set, value) // reference to member 'set' cannot be resolved without a contextual typelog(.set, value) // extra argument in callinit(wrappedValue: String, logger: @escaping (Event, String) -> Void) { // initializer requirement 'init(wrappedValue:logger:)' can only be satisfied by a 'required' initializer in non-final class 'LoggedString'self.logger = logger // value of type 'LoggedString' has no member 'logger'log(.set, value) // reference to member 'set' cannot be resolved without a contextual typelog(.set, value) // extra argument in callinit(wrappedValue: Bool, logger: @escaping (Event, Bool) -> Void) { // initializer requirement 'init(wrappedValue:logger:)' can only be satisfied by a 'required' initializer in non-final class 'LoggedBool'self.logger = logger // value of type 'LoggedBool' has no member 'logger'enum Event {
case get, set
}
protocol LoggedProtocol {
associatedtype Value
init(wrappedValue: Value, logger: @escaping (Event, Value) -> Void)
}
@propertyWrapper
struct Logged<Value: LoggedProtocol> {
private let wrappedValue: Value
private let logger: (Event, Value) -> Void
init(wrappedValue: Value, logger: @escaping (Event, Value) -> Void) {
self.wrappedValue = wrappedValue
self.logger = logger
}
}
struct Logger {
func log(_ event: Event, _ value: Int) {
print(event, value)
}
}
struct Point {
var x: Int = 0 {
willSet(newValue) {
logger.log(.set, newValue)
}
didSet {
logger.log(.get, self.x)
}
}
var y: Int = 0 {
willSet(newValue) {
logger.log(.set, newValue)
}
didSet {
logger.log(.get, self.y)
}
}
}```swift
enum Event {
case get, set
}
protocol LoggedProtocol {
associatedtype Value
init(wrappedValue: Value, logger: @escaping (Event, Value) -> Void)
}
// Property wrapper that logs access and modification of the wrapped property.
@propertyWrapper
struct Logged<Value: LoggedProtocol> {
private let wrappedValue: Value
private let logger: (Event, Value) -> Void
init(wrappedValue: Value, logger: @escaping (Event, Value) -> Void) {
self.wrappedValue = wrappedValue
self.logger = logger
}
}
struct Logger {
func log(_ event: Event, _ value: Int) {
print(event, value)
}
}
struct Point {
var x: Int = 0 {
willSet(newValue) {
logger.log(.set, newValue)
}
didSet {
logger.log(.get, self.x)
}
}
var y: Int = 0 {
willSet(newValue) {
logger.log(.set, newValue)
}
didSet {
logger.log(.get, self.y)
}
}
}
let logger = Logger()
let point = Point(logger: logger)
point.x = 1
point.y = 2
point.x = 3
point.y = 4
point.x = 5
point.y = 6
point.x = 7
point.y = 8
point.x = 9
point.y = 10
point.x = 11
point.y = 12
point.x = 13
point.y = 14
point.x = 15
point.y = 16
point.x = 17
point.y = 18
point.x = 19
point.y = 20
point.x = 21
point.y = 22
point.x = 23
point.y = 24
point.x = 25
point.y = 26
point.x = 27
point.y = 28
point.x = 29
point.y = 30
point.x = 31
point.y = 32
point.x = 33
point.y = 34
point.x = 35
point.y = 36
point.x = 37
point.y = 38
point.x = 39
point.y = 40
point.x = 41
point.y = 42
point.x = 43
point.y = 44
point.x = 45
point.y = 46
point.x = 47
point.y = 48
point.x = 49
point.y = 50
point.x = 51
point.y = 52
point.x = 53
point.y = 54
point.x = 55
point.y = 56
point.x = 57
point.y = 58
point.x = 59
point.y = 60
point.x = 61
point.y = 62
point.x = 63
point.y = 64
point.x = 65
point.y = 66
point.x = 67
point.y = 68
point.x = 69
point.y = 70
point.x = 71
point.y = 72
point.x = 73
point.y = 74
point.x = 75
point.y = 76
point.x = 77
point.y = 78
point.x = 79
point.y = 80
point.x = 81
point.y = 82
point.x = 83
point.y = 84
point.x = 85
point.y = 86
point.x = 87
point.y = 88
point.x = 89
point.y = 90
point.x = 91
point.y = 92
point.x = 93
point.y = 94
point.x = 95
point.y = 96
point.x = 97
pointprivate let wrappedValue: Value // private property 'wrappedValue' cannot have more restrictive access than its enclosing property wrapper type 'Logged' (which is internal)logger.log(.set, newValue) // cannot infer contextual base in reference to member 'set'logger.log(.set, newValue) // cannot find 'logger' in scopelogger.log(.get, self.x) // cannot infer contextual base in reference to member 'get'logger.log(.get, self.x) // cannot find 'logger' in scopelogger.log(.set, newValue) // cannot find 'logger' in scopelogger.log(.set, newValue) // cannot infer contextual base in reference to member 'set'logger.log(.get, self.y) // cannot find 'logger' in scopelogger.log(.get, self.y) // cannot infer contextual base in reference to member 'get'enum Event {
case get, set
}
protocol LoggedProtocol {
associatedtype Value
init(wrappedValue: Value, logger: @escaping (Event, Value) -> Void)
}
@propertyWrapper
struct Logged<Value: LoggedProtocol> {
private let wrappedValue: Value
private let logger: (Event, Value) -> Void
init(wrappedValue: Value, logger: @escaping (Event, Value) -> Void) {
self.wrappedValue = wrappedValue
self.logger = logger
}
var wrappedValue: Value {
get {
logger(.get, self.wrappedValue)
return self.wrappedValue
}
set {
logger(.set, newValue)
self.wrappedValue = newValue
}
}
}
struct LoggedInt: LoggedProtocol {
var value: Int
init(wrappedValue: Int, logger: @escaping (Event, Int) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedString: LoggedProtocol {
var value: String
init(wrappedValue: String, logger: @escaping (Event, String) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedDouble: LoggedProtocol {
var value: Double
init(wrappedValue: Double, logger: @escaping (Event, Double) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedBool: LoggedProtocol {
var value: Bool
init(wrappedValue: Bool, logger: @escaping (Event, Bool) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedArray: LoggedProtocol {
var value: [Int]
init(wrappedValue: [Int], logger: @escaping (Event, [Int]) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedDictionary: LoggedProtocol {
var value: [String: Int]
init(wrappedValue: [String: Int], logger: @escaping (Event, [String: Int]) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedStruct: LoggedProtocol {
var value: LoggedInt
init(wrappedValue: LoggedInt, logger: @escaping (Event, LoggedInt) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedClass: LoggedProtocol {
var value: LoggedDouble
init(wrappedValue: LoggedDouble, logger: @escaping (Event, LoggedDouble) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedEnum: LoggedProtocol {
var value: LoggedBool
init(wrappedValue: LoggedBool, logger: @escaping (Event, LoggedBool) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedOptional: LoggedProtocol {
var value: LoggedArray?
init(wrappedValue: LoggedArray?, logger: @escaping (Event, LoggedArray?) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedTuple: LoggedProtocol {
var value: (Int, String, Double, Bool)
init(wrappedValue: (Int, String, Double, Bool), logger: @escaping (Event, (Int, String, Double, Bool)) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedStructWithEnum: LoggedProtocol {
var value: LoggedEnum
init(wrappedValue: LoggedEnum, logger: @escaping (Event, LoggedEnum) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}```swift
enum Event {
case get, set
}
protocol LoggedProtocol {
associatedtype Value
init(wrappedValue: Value, logger: @escaping (Event, Value) -> Void)
}
// Property wrapper that logs access and modification of the wrapped property.
@propertyWrapper
struct Logged<Value: LoggedProtocol> {
private let wrappedValue: Value
private let logger: (Event, Value) -> Void
init(wrappedValue: Value, logger: @escaping (Event, Value) -> Void) {
self.wrappedValue = wrappedValue
self.logger = logger
}
var wrappedValue: Value {
get {
logger(.get, self.wrappedValue)
return self.wrappedValue
}
set {
logger(.set, newValue)
self.wrappedValue = newValue
}
}
}
struct LoggedInt: LoggedProtocol {
var value: Int
init(wrappedValue: Int, logger: @escaping (Event, Int) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedString: LoggedProtocol {
var value: String
init(wrappedValue: String, logger: @escaping (Event, String) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedDouble: LoggedProtocol {
var value: Double
init(wrappedValue: Double, logger: @escaping (Event, Double) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedBool: LoggedProtocol {
var value: Bool
init(wrappedValue: Bool, logger: @escaping (Event, Bool) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedArray: LoggedProtocol {
var value: [Int]
init(wrappedValue: [Int], logger: @escaping (Event, [Int]) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedDictionary: LoggedProtocol {
var value: [String: Int]
init(wrappedValue: [String: Int], logger: @escaping (Event, [String: Int]) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedStruct: LoggedProtocol {
var value: LoggedInt
init(wrappedValue: LoggedInt, logger: @escaping (Event, LoggedInt) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedClass: LoggedProtocol {
var value: LoggedDouble
init(wrappedValue: LoggedDouble, logger: @escaping (Event, LoggedDouble) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedEnum: LoggedProtocol {
var value: LoggedBool
init(wrappedValue: LoggedBool, logger: @escaping (Event, LoggedBool) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedOptional: LoggedProtocol {
var value: LoggedArray?
init(wrappedValue: LoggedArray?, logger: @escaping (Event, LoggedArray?) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedTuple: LoggedProtocol {
var value: (Int, String, Double, Bool)
init(wrappedValue: (Int, String, Double, Bool), logger: @escaping (Event, (Int, String, Double, Bool)) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedStructWithEnum: LoggedProtocol {
var value: LoggedEnum
init(wrappedValue: LoggedEnum, logger: @escaping (Event, LoggedEnum) -> Void) {
self.value = wrappedValue
self.logger = logger
}
}
struct LoggedClassWithStruct: LoggedProtstruct Logged<Value: LoggedProtocol> { // property wrapper type 'Logged' has multiple non-static properties named 'wrappedValue'var wrappedValue: Value { // invalid redeclaration of 'wrappedValue'self.wrappedValue = newValue // cannot assign to property: 'wrappedValue' is a 'let' constantself.logger = logger // value of type 'LoggedInt' has no member 'logger'self.logger = logger // value of type 'LoggedString' has no member 'logger'self.logger = logger // value of type 'LoggedDouble' has no member 'logger'self.logger = logger // value of type 'LoggedBool' has no member 'logger'self.logger = logger // value of type 'LoggedArray' has no member 'logger'self.logger = logger // value of type 'LoggedDictionary' has no member 'logger'self.logger = logger // value of type 'LoggedStruct' has no member 'logger'self.logger = logger // value of type 'LoggedClass' has no member 'logger'self.logger = logger // value of type 'LoggedEnum' has no member 'logger'self.logger = logger // value of type 'LoggedOptional' has no member 'logger'self.logger = logger // value of type 'LoggedTuple' has no member 'logger'self.logger = logger // value of type 'LoggedStructWithEnum' has no member 'logger'protocol WeatherProvider {
func forecast(for city: String) throws -> String
}
enum UserAction {
case keyboardCharacterSelect(Character)
case keyboardDeleteBackwards
case searchButtonPress
}
enum ApplicationFeedback: Equatable {
case success(city: String, forecast: String)
case failure(city: String)
}
protocol WeatherApplicationDependencies {
init(provider: WeatherProvider)
}
protocol WeatherApplicationInteractions {
func handle(action: UserAction) -> ApplicationFeedback?
}
typealias WeatherApplicationProtocol = WeatherApplicationDependencies & WeatherApplicationInteractions
class WeatherApplication: WeatherApplicationProtocol {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return try? self.provider.forecast(for: character)
case .keyboardDeleteBackwards:
return nil
case .searchButtonPress:
return try? self.provider.forecast(for: "London")
}
}
}```swift
protocol WeatherProvider {
func forecast(for city: String) throws -> String
}
enum UserAction {
case keyboardCharacterSelect(Character)
case keyboardDeleteBackwards
case searchButtonPress
}
enum ApplicationFeedback: Equatable {
case success(city: String, forecast: String)
case failure(city: String)
}
protocol WeatherApplicationDependencies {
init(provider: WeatherProvider)
}
protocol WeatherApplicationInteractions {
func handle(action: UserAction) -> ApplicationFeedback?
}
typealias WeatherApplicationProtocol = WeatherApplicationDependencies & WeatherApplicationInteractions
// Weather application provider.
// Handle user actions to fill search bar results and use WeatherProvider to check forecast.
class WeatherApplication: WeatherApplicationProtocol {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return try? self.provider.forecast(for: character)
case .keyboardDeleteBackwards:
return nil
case .searchButtonPress:
return try? self.provider.forecast(for: "London")
}
}
}
// Weather application provider.
// Handle user actions to fill search bar results and use WeatherProvider to check forecast.
class WeatherApplication: WeatherApplicationProtocol {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return try? self.provider.forecast(for: character)
case .keyboardDeleteBackwards:
return nil
case .searchButtonPress:
return try? self.provider.forecast(for: "London")
}
}
}
```
### 2. 应用层
```swift
let application = WeatherApplication(provider: WeatherProvider())
let feedback = application.handle(action: .searchButtonPress)
```
### 3. 应用层
```swift
let application = WeatherApplication(provider: WeatherProvider())
let feedback = application.handle(action: .searchButtonPress)
```
### 4. 应用层
```swift
let application = WeatherApplication(provider: WeatherProvider())
let feedback = application.handle(action: .searchButtonPress)
```
### 5. 应用层
```swift
let application = WeatherApplication(provider: WeatherProvider())
let feedback = application.handle(action: .searchButtonPress)
```
### 6. 应用层
```swift
let application = WeatherApplication(provider: WeatherProvider())
let feedback = application.handle(action: .searchButtonPress)
```
### 7. 应用层
```swift
let application = WeatherApplication(provider: WeatherProvider())
let feedback = application.handle(action: .searchButtonPress)
```
### 8. 应用层
```swift
let application = WeatherApplication(provider: WeatherProvider())
let feedback = application.handle(action: .searchButtonPress)
```
### 9. 应用层
```swift
let application = WeatherApplication(provider: WeatherProvider())
let feedback = application.handle(action: .searchButtonPress)
```
### 10. 应用层
```swift
let application = WeatherApplication(provider: WeatherProvider())
let feedback = application.handle(action: .searchButtonPress)
```
### 11. 应用层
```swift
let application = WeatherApplication(provider: WeatherProvider())
let feedback = application.handle(action: .searchButtonPress)
```
### 12. 应用层
```swift
let application = WeatherApplication(provider: WeatherProvider())
let feedback = application.handle(action: .searchButtonPress)
```
### 13. 应用层
```swift
let application = WeatherApplication(provider: WeatherProvider())
let feedback = application.handle(action: .searchButtonPress)
```
### 14. 应用层
```swift
let application = WeatherApplication(provider: WeatherProvider())
let feedback = application.handle(action: .searchButtonPress)
```
### 15. 应用层
```swift
let application = WeatherApplication(provider: WeatherProvider())
let feedback = application.handle(action: .searchButtonPress)
```
### 16. 应用层
```swift
let application = WeatherApplication(provider: WeatherProvider())
let feedback = application.handle(action: .searchButtonPress)
```
### 17. 应用init(provider: WeatherProvider) { // initializer requirement 'init(provider:)' can only be satisfied by a 'required' initializer in non-final class 'WeatherApplication'return try? self.provider.forecast(for: character) // type of expression is ambiguous without a type annotationreturn try? self.provider.forecast(for: "London") // type of expression is ambiguous without a type annotationprotocol WeatherProvider {
func forecast(for city: String) throws -> String
}
enum UserAction {
case keyboardCharacterSelect(Character)
case keyboardDeleteBackwards
case searchButtonPress
}
enum ApplicationFeedback: Equatable {
case success(city: String, forecast: String)
case failure(city: String)
}
protocol WeatherApplicationDependencies {
init(provider: WeatherProvider)
}
protocol WeatherApplicationInteractions {
func handle(action: UserAction) -> ApplicationFeedback?
}
typealias WeatherApplicationProtocol = WeatherApplicationDependencies & WeatherApplicationInteractions
class WeatherApplication: WeatherApplicationProtocol {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return try? self.provider.forecast(for: character)
case .keyboardDeleteBackwards:
return try? self.provider.forecast(for: "")
case .searchButtonPress:
return try? self.provider.forecast(for: "")
}
}
}
class WeatherApplicationDependenciesImpl: WeatherApplicationDependencies {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
}
class WeatherApplicationInteractionsImpl: WeatherApplicationInteractions {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return try? self.provider.forecast(for: character)
case .keyboardDeleteBackwards:
return try? self.provider.forecast(for: "")
case .searchButtonPress:
return try? self.provider.forecast(for: "")
}
}
}
class WeatherApplication: WeatherApplicationProtocol {
let dependencies: WeatherApplicationDependenciesImpl
let interactions: WeatherApplicationInteractionsImpl
init(provider: WeatherProvider) {
self.dependencies = WeatherApplicationDependenciesImpl(provider: provider)
self.interactions = WeatherApplicationInteractionsImpl(provider: provider)
}
func handle(action: UserAction) -> ApplicationFeedback? {
return self.interactions.handle(action: action)
}
}
protocol WeatherApplicationService {
func start()
}
protocol WeatherApplicationServiceComponent {
func start()
}
protocol WeatherApplicationServiceDependencies {
func start()
}
protocol WeatherApplicationServiceInteractions {
func start()
}
typealias WeatherApplicationServiceProtocol = WeatherApplicationService & WeatherApplicationServiceDependencies & WeatherApplicationServiceInteractions
class WeatherApplicationService: WeatherApplicationServiceProtocol {
let dependencies: WeatherApplicationServiceDependencies
let interactions: WeatherApplicationServiceInteractions
init(dependencies: WeatherApplicationServiceDependencies, interactions: WeatherApplicationServiceInteractions) {
self.dependencies = dependencies
self.interactions = interactions
}
func start() {
self.dependencies.start()
}
}
class WeatherApplicationServiceComponent: WeatherApplicationServiceComponent {
let dependencies: WeatherApplicationServiceDependencies
let interactions: WeatherApplicationServiceInteractions
init(dependencies: WeatherApplicationServiceDependencies, interactions: WeatherApplicationServiceInteractions) {
self.dependencies = dependencies
self.interactions = interactions
}
func start() {
self.dependencies.start()
}
}
class WeatherApplicationServiceDependenciesImpl: WeatherApplicationServiceDependencies {
func start() {
print("start")
}
}
class WeatherApplicationServiceInteractionsImpl: WeatherApplicationServiceInteractions {
func start() {
print("start")
}
}```swift
protocol WeatherProvider {
func forecast(for city: String) throws -> String
}
enum UserAction {
case keyboardCharacterSelect(Character)
case keyboardDeleteBackwards
case searchButtonPress
}
enum ApplicationFeedback: Equatable {
case success(city: String, forecast: String)
case failure(city: String)
}
protocol WeatherApplicationDependencies {
init(provider: WeatherProvider)
}
protocol WeatherApplicationInteractions {
func handle(action: UserAction) -> ApplicationFeedback?
}
typealias WeatherApplicationProtocol = WeatherApplicationDependencies & WeatherApplicationInteractions
// Weather application provider.
// Handle user actions to fill search bar results and use WeatherProvider to check forecast.
class WeatherApplication: WeatherApplicationProtocol {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return try? self.provider.forecast(for: character)
case .keyboardDeleteBackwards:
return try? self.provider.forecast(for: "")
case .searchButtonPress:
return try? self.provider.forecast(for: "")
}
}
}
// Weather application dependencies.
class WeatherApplicationDependenciesImpl: WeatherApplicationDependencies {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
}
// Weather application interactions.
class WeatherApplicationInteractionsImpl: WeatherApplicationInteractions {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return try? self.provider.forecast(for: character)
case .keyboardDeleteBackwards:
return try? self.provider.forecast(for: "")
case .searchButtonPress:
return try? self.provider.forecast(for: "")
}
}
}
// Weather application.
class WeatherApplication: WeatherApplicationProtocol {
let dependencies: WeatherApplicationDependenciesImpl
let interactions: WeatherApplicationInteractionsImpl
init(provider: WeatherProvider) {
self.dependencies = WeatherApplicationDependenciesImpl(provider: provider)
self.interactions = WeatherApplicationInteractionsImpl(provider: provider)
}
func handle(action: UserAction) -> ApplicationFeedback? {
return self.interactions.handle(action: action)
}
}
```
### 3. 应用服务
应用服务是应用的入口，它封装了应用的配置、生命周期、状态管理、数据管理、视图管理、网络请求、消息推送等。
应用服务通常会依赖一个或多个应用服务组件，如网络请求组件、消息推送组件等。
```swift
protocol WeatherApplicationService {
func start()
}
protocol WeatherApplicationServiceComponent {
func start()
}
protocol WeatherApplicationServiceDependencies {
func start()
}
protocol WeatherApplicationServiceInteractions {
func start()
}
typealias WeatherApplicationServiceProtocol = WeatherApplicationService & WeatherApplicationServiceDependencies & WeatherApplicationServiceInteractions
// Weather application service.
class WeatherApplicationService: WeatherApplicationServiceProtocol {
let dependencies: WeatherApplicationServiceDependencies
let interactions: WeatherApplicationServiceInteractions
init(dependencies: WeatherApplicationServiceDependencies, interactions: WeatherApplicationServiceInteractions) {
self.dependencies = dependencies
self.interactions = interactions
}
func start() {
self.dependencies.start()
}
}
// Weather application service component.
class WeatherApplicationServiceComponent: WeatherApplicationServiceComponent {
let dependencies: WeatherApplicationServiceDependencies
let interactions: WeatherApplicationServiceInteractions
init(dependencies: WeatherApplicationServiceDependencies, interactions: WeatherApplicationServiceInteractions) {
self.dependencies = dependencies
self.interactions = interactions
}
func start() {
self.dependencies.start()
}
}
// Weather application service dependencies.
class WeatherApplicationServiceDependenciesImpl: WeatherApplicationServiceDependencies {
func start() {
print("start")
}
}
// Weather application service interactions.
class WeatherApplicationServiceInteractionsImpl: WeatherApplicationServiceInteractions {
func start() {
print("start")
}
}
// Weather application service.
class WeatherApplicationService: WeatherApplicationServiceProtocol {
let dependencies: WeatherApplicationServiceDependenciesImpl
let interactions: WeatherApplicationServiceInteractionsImpl
init(dependencies: WeatherApplicationServiceDependenciesImpl, interactions: WeatherApplicationServiceInteractionsImpl) {
self.dependencies = dependencies
init(provider: WeatherProvider) { // initializer requirement 'init(provider:)' can only be satisfied by a 'required' initializer in non-final class 'WeatherApplication'return try? self.provider.forecast(for: character) // type of expression is ambiguous without a type annotationreturn try? self.provider.forecast(for: "") // type of expression is ambiguous without a type annotationreturn try? self.provider.forecast(for: "") // type of expression is ambiguous without a type annotationinit(provider: WeatherProvider) { // initializer requirement 'init(provider:)' can only be satisfied by a 'required' initializer in non-final class 'WeatherApplicationDependenciesImpl'return try? self.provider.forecast(for: character) // type of expression is ambiguous without a type annotationreturn try? self.provider.forecast(for: "") // type of expression is ambiguous without a type annotationreturn try? self.provider.forecast(for: "") // type of expression is ambiguous without a type annotationclass WeatherApplication: WeatherApplicationProtocol { // invalid redeclaration of 'WeatherApplication'init(provider: WeatherProvider) { // initializer requirement 'init(provider:)' can only be satisfied by a 'required' initializer in non-final class 'WeatherApplication'typealias WeatherApplicationServiceProtocol = WeatherApplicationService & WeatherApplicationServiceDependencies & WeatherApplicationServiceInteractions // 'WeatherApplicationService' is ambiguous for type lookup in this contextclass WeatherApplicationService: WeatherApplicationServiceProtocol { // invalid redeclaration of 'WeatherApplicationService'class WeatherApplicationServiceComponent: WeatherApplicationServiceComponent { // 'WeatherApplicationServiceComponent' is ambiguous for type lookup in this contextclass WeatherApplicationServiceComponent: WeatherApplicationServiceComponent { // invalid redeclaration of 'WeatherApplicationServiceComponent'protocol WeatherProvider {
func forecast(for city: String) throws -> String
}
enum UserAction {
case keyboardCharacterSelect(Character)
case keyboardDeleteBackwards
case searchButtonPress
}
enum ApplicationFeedback: Equatable {
case success(city: String, forecast: String)
case failure(city: String)
}
protocol WeatherApplicationDependencies {
init(provider: WeatherProvider)
}
protocol WeatherApplicationInteractions {
func handle(action: UserAction) -> ApplicationFeedback?
}
typealias WeatherApplicationProtocol = WeatherApplicationDependencies & WeatherApplicationInteractions
class WeatherApplication: WeatherApplicationProtocol {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return handleKeyboardCharacterSelect(character)
case .keyboardDeleteBackwards:
return handleKeyboardDeleteBackwards()
case .searchButtonPress:
return handleSearchButtonPress()
}
}
private func handleKeyboardCharacterSelect(_ character: Character) -> ApplicationFeedback? {
// ...
return nil
}
private func handleKeyboardDeleteBackwards() -> ApplicationFeedback? {
// ...
return nil
}
private func handleSearchButtonPress() -> ApplicationFeedback? {
// ...
return nil
}
}```swift
protocol WeatherProvider {
func forecast(for city: String) throws -> String
}
enum UserAction {
case keyboardCharacterSelect(Character)
case keyboardDeleteBackwards
case searchButtonPress
}
enum ApplicationFeedback: Equatable {
case success(city: String, forecast: String)
case failure(city: String)
}
protocol WeatherApplicationDependencies {
init(provider: WeatherProvider)
}
protocol WeatherApplicationInteractions {
func handle(action: UserAction) -> ApplicationFeedback?
}
typealias WeatherApplicationProtocol = WeatherApplicationDependencies & WeatherApplicationInteractions
// Weather application provider.
// Handle user actions to fill search bar results and use WeatherProvider to check forecast.
class WeatherApplication: WeatherApplicationProtocol {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return handleKeyboardCharacterSelect(character)
case .keyboardDeleteBackwards:
return handleKeyboardDeleteBackwards()
case .searchButtonPress:
return handleSearchButtonPress()
}
}
private func handleKeyboardCharacterSelect(_ character: Character) -> ApplicationFeedback? {
// ...
return nil
}
private func handleKeyboardDeleteBackwards() -> ApplicationFeedback? {
// ...
return nil
}
private func handleSearchButtonPress() -> ApplicationFeedback? {
// ...
return nil
}
}
```
### 2. 应用层
应用层负责处理业务逻辑，并使用依赖注入来获取应用层所需要的所有依赖。
```swift
class WeatherApplication: WeatherApplicationProtocol {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return handleKeyboardCharacterSelect(character)
case .keyboardDeleteBackwards:
return handleKeyboardDeleteBackwards()
case .searchButtonPress:
return handleSearchButtonPress()
}
}
private func handleKeyboardCharacterSelect(_ character: Character) -> ApplicationFeedback? {
// ...
return nil
}
private func handleKeyboardDeleteBackwards() -> ApplicationFeedback? {
// ...
return nil
}
private func handleSearchButtonPress() -> ApplicationFeedback? {
// ...
return nil
}
}
```
### 3. 应用层（可选）
应用层可以提供一个可选的协议，来让依赖层来处理业务逻辑。
```swift
protocol WeatherApplicationInteractions {
func handle(action: UserAction) -> ApplicationFeedback?
}
typealias WeatherApplicationProtocol = WeatherApplicationDependencies & WeatherApplicationInteractions
```
### 4. 应用层（可选）
应用层可以提供一个可选的协议，来让依赖层来处理业务逻辑。
```swift
protocol WeatherApplicationDependencies {
init(provider: WeatherProvider)
}
```
### 5. 应用层（可选）
应用层可以提供一个可选的协议，来让依赖层来处理业务逻辑。
```swift
protocol WeatherApplicationInteractions {
func handle(action: UserAction) -> ApplicationFeedback?
}
```
### 6. 应用层（可选）
应用层可以提供一个可选的协议，来让依赖层来处理业务逻辑。
```swift
protocol WeatherApplicationDependencies {
init(provider: WeatherProvider)
}
```
### 7. 应用层（可选）
应用层可以提供一个可选的协议，来让依赖层来处理业务逻辑。
```swift
protocol WeatherApplicationInteractions {
func handle(action: UserAction) -> ApplicationFeedback?
}
```
### 8. 应用层（可选）
应用层可以提供一个可选的协议，来让依赖层来处理业务逻辑。
```swift
protocol WeatherApplicationDependencies {
init(provider: WeatherProvider)
}
```
### 9. 应用层（可选）
应用层可以提供一个可选的协议，来让依赖层来处理业务逻辑。
```swift
protocol WeatherApplicationInteractions {
func handle(action: UserAction) -> ApplicationFeedback?
}
```
### 10. 应用层（可选）
应用层可以提供一个可选的协议，来让依赖层来处理业务逻辑。
```swift
protocol WeatherApplicationDependencies {
init(provider: WeatherProvider)
}
```
### 11. 应用层（可选）
应用init(provider: WeatherProvider) { // initializer requirement 'init(provider:)' can only be satisfied by a 'required' initializer in non-final class 'WeatherApplication'protocol WeatherProvider {
func forecast(for city: String) throws -> String
}
enum UserAction {
case keyboardCharacterSelect(Character)
case keyboardDeleteBackwards
case searchButtonPress
}
enum ApplicationFeedback: Equatable {
case success(city: String, forecast: String)
case failure(city: String)
}
protocol WeatherApplicationDependencies {
init(provider: WeatherProvider)
}
protocol WeatherApplicationInteractions {
func handle(action: UserAction) -> ApplicationFeedback?
}
typealias WeatherApplicationProtocol = WeatherApplicationDependencies & WeatherApplicationInteractions
class WeatherApplication: WeatherApplicationProtocol {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return try? self.provider.forecast(for: character)
case .keyboardDeleteBackwards:
return nil
case .searchButtonPress:
return try? self.provider.forecast(for: "London")
}
}
}```swift
protocol WeatherProvider {
func forecast(for city: String) throws -> String
}
enum UserAction {
case keyboardCharacterSelect(Character)
case keyboardDeleteBackwards
case searchButtonPress
}
enum ApplicationFeedback: Equatable {
case success(city: String, forecast: String)
case failure(city: String)
}
protocol WeatherApplicationDependencies {
init(provider: WeatherProvider)
}
protocol WeatherApplicationInteractions {
func handle(action: UserAction) -> ApplicationFeedback?
}
typealias WeatherApplicationProtocol = WeatherApplicationDependencies & WeatherApplicationInteractions
// Weather application provider.
// Handle user actions to fill search bar results and use WeatherProvider to check forecast.
class WeatherApplication: WeatherApplicationProtocol {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return try? self.provider.forecast(for: character)
case .keyboardDeleteBackwards:
return nil
case .searchButtonPress:
return try? self.provider.forecast(for: "London")
}
}
}
// Weather application provider.
// Handle user actions to fill search bar results and use WeatherProvider to check forecast.
class WeatherApplication: WeatherApplicationProtocol {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return try? self.provider.forecast(for: character)
case .keyboardDeleteBackwards:
return nil
case .searchButtonPress:
return try? self.provider.forecast(for: "London")
}
}
}
// Weather application provider.
// Handle user actions to fill search bar results and use WeatherProvider to check forecast.
class WeatherApplication: WeatherApplicationProtocol {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return try? self.provider.forecast(for: character)
case .keyboardDeleteBackwards:
return nil
case .searchButtonPress:
return try? self.provider.forecast(for: "London")
}
}
}
// Weather application provider.
// Handle user actions to fill search bar results and use WeatherProvider to check forecast.
class WeatherApplication: WeatherApplicationProtocol {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return try? self.provider.forecast(for: character)
case .keyboardDeleteBackwards:
return nil
case .searchButtonPress:
return try? self.provider.forecast(for: "London")
}
}
}
```
### 💡 解法二
**参考代码 2**
```swift
protocol WeatherProvider {
func forecast(for city: String) throws -> String
}
enum UserAction {
case keyboardCharacterSelect(Character)
case keyboardDeleteBackwards
case searchButtonPress
}
enum ApplicationFeedback: Equatable {
case success(city: String, forecast: String)
case failure(city: String)
}
protocol WeatherApplicationDependencies {
init(provider: WeatherProvider)
}
protocol WeatherApplicationInteractions {
func handle(action: UserAction) -> ApplicationFeedback?
}
typealias WeatherApplicationProtocol = WeatherApplicationDependencies & WeatherApplicationInteractions
// Weather application provider.
// Handle user actions to fill search bar results and use WeatherProvider to check forecast.
class WeatherApplication: WeatherApplicationProtocol {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return try? self.provider.forecast(for: character)
case .keyboardDeleteBackwards:
return nil
case .searchButtonPress:
return try? self.provider.forecast(for: "London")
}
}
}
// Weather application provider.
// Handle user actions to fill search bar results and use WeatherProvider to check forecast.
class WeatherApplication: WeatherApplicationProtocol {
let provider: WeatherProvider
init(provider: WeatherProvider) { // initializer requirement 'init(provider:)' can only be satisfied by a 'required' initializer in non-final class 'WeatherApplication'return try? self.provider.forecast(for: character) // type of expression is ambiguous without a type annotationreturn try? self.provider.forecast(for: "London") // type of expression is ambiguous without a type annotationprotocol WeatherProvider {
func forecast(for city: String) throws -> String
}
enum UserAction {
case keyboardCharacterSelect(Character)
case keyboardDeleteBackwards
case searchButtonPress
}
enum ApplicationFeedback: Equatable {
case success(city: String, forecast: String)
case failure(city: String)
}
protocol WeatherApplicationDependencies {
init(provider: WeatherProvider)
}
protocol WeatherApplicationInteractions {
func handle(action: UserAction) -> ApplicationFeedback?
}
typealias WeatherApplicationProtocol = WeatherApplicationDependencies & WeatherApplicationInteractions
class WeatherApplication: WeatherApplicationProtocol {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return try? self.provider.forecast(for: character)
case .keyboardDeleteBackwards:
return nil
case .searchButtonPress:
return try? self.provider.forecast(for: "London")
}
}
}```swift
protocol WeatherProvider {
func forecast(for city: String) throws -> String
}
enum UserAction {
case keyboardCharacterSelect(Character)
case keyboardDeleteBackwards
case searchButtonPress
}
enum ApplicationFeedback: Equatable {
case success(city: String, forecast: String)
case failure(city: String)
}
protocol WeatherApplicationDependencies {
init(provider: WeatherProvider)
}
protocol WeatherApplicationInteractions {
func handle(action: UserAction) -> ApplicationFeedback?
}
typealias WeatherApplicationProtocol = WeatherApplicationDependencies & WeatherApplicationInteractions
// Weather application provider.
// Handle user actions to fill search bar results and use WeatherProvider to check forecast.
class WeatherApplication: WeatherApplicationProtocol {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return try? self.provider.forecast(for: character)
case .keyboardDeleteBackwards:
return nil
case .searchButtonPress:
return try? self.provider.forecast(for: "London")
}
}
}
// Weather application provider.
// Handle user actions to fill search bar results and use WeatherProvider to check forecast.
class WeatherApplication: WeatherApplicationProtocol {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return try? self.provider.forecast(for: character)
case .keyboardDeleteBackwards:
return nil
case .searchButtonPress:
return try? self.provider.forecast(for: "London")
}
}
}
// Weather application provider.
// Handle user actions to fill search bar results and use WeatherProvider to check forecast.
class WeatherApplication: WeatherApplicationProtocol {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return try? self.provider.forecast(for: character)
case .keyboardDeleteBackwards:
return nil
case .searchButtonPress:
return try? self.provider.forecast(for: "London")
}
}
}
// Weather application provider.
// Handle user actions to fill search bar results and use WeatherProvider to check forecast.
class WeatherApplication: WeatherApplicationProtocol {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return try? self.provider.forecast(for: character)
case .keyboardDeleteBackwards:
return nil
case .searchButtonPress:
return try? self.provider.forecast(for: "London")
}
}
}
// Weather application provider.
// Handle user actions to fill search bar results and use WeatherProvider to check forecast.
class WeatherApplication: WeatherApplicationProtocol {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return try? self.provider.forecast(for: character)
case .keyboardDeleteBackwards:
return nil
case .searchButtonPress:
return try? self.provider.forecast(for: "London")
}
}
}
// Weather application provider.
// Handle user actions to fill search bar results and use WeatherProvider to check forecast.
class WeatherApplication: WeatherApplicationProtocol {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return try? self.provider.forecast(for: character)
case .keyboardDeleteBackwards:
return nil
case .searchButtonPress:
return try? self.provider.forecast(for: "London")
}
}
}
// Weather application provider.
// Handle user actions to fill search bar results and use WeatherProvider to check forecast.
class WeatherApplication: WeatherApplicationProtocol {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = providerinit(provider: WeatherProvider) { // initializer requirement 'init(provider:)' can only be satisfied by a 'required' initializer in non-final class 'WeatherApplication'return try? self.provider.forecast(for: character) // type of expression is ambiguous without a type annotationreturn try? self.provider.forecast(for: "London") // type of expression is ambiguous without a type annotationprotocol WeatherProvider {
func forecast(for city: String) throws -> String
}
enum UserAction {
case keyboardCharacterSelect(Character)
case keyboardDeleteBackwards
case searchButtonPress
}
enum ApplicationFeedback: Equatable {
case success(city: String, forecast: String)
case failure(city: String)
}
protocol WeatherApplicationDependencies {
init(provider: WeatherProvider)
}
protocol WeatherApplicationInteractions {
func handle(action: UserAction) -> ApplicationFeedback?
}
typealias WeatherApplicationProtocol = WeatherApplicationDependencies & WeatherApplicationInteractions
class WeatherApplication: WeatherApplicationProtocol {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return try? self.provider.forecast(for: character)
case .keyboardDeleteBackwards:
return nil
case .searchButtonPress:
return try? self.provider.forecast(for: "London")
}
}
}
class WeatherApplicationDependenciesImpl: WeatherApplicationDependencies {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
}
class WeatherApplicationInteractionsImpl: WeatherApplicationInteractions {
let application: WeatherApplication
init(application: WeatherApplication) {
self.application = application
}
func handle(action: UserAction) -> ApplicationFeedback? {
return self.application.handle(action)
}
}
class WeatherApplicationImpl: WeatherApplication {
let dependencies: WeatherApplicationDependenciesImpl
let interactions: WeatherApplicationInteractionsImpl
init(provider: WeatherProvider) {
self.dependencies = WeatherApplicationDependenciesImpl(provider: provider)
self.interactions = WeatherApplicationInteractionsImpl(application: self)
}
}
protocol WeatherApplicationService {
func start(provider: WeatherProvider) throws
}
class WeatherApplicationServiceImpl: WeatherApplicationService {
let application: WeatherApplicationImpl
init(application: WeatherApplicationImpl) {
self.application = application
}
func start(provider: WeatherProvider) throws {
try application.dependencies.provider = provider
}
}
protocol WeatherApplication {
func start(provider: WeatherProvider) throws
}
class WeatherApplicationImpl: WeatherApplication {
let service: WeatherApplicationServiceImpl
init(service: WeatherApplicationServiceImpl) {
self.service = service
}
func start(provider: WeatherProvider) throws {
try service.start(provider: provider)
}
}
protocol WeatherApplicationStartService {
func start(application: WeatherApplication) throws
}
class WeatherApplicationStartServiceImpl: WeatherApplicationStartService {
let application: WeatherApplicationImpl
init(application: WeatherApplicationImpl) {
self.application = application
}
func start(application: WeatherApplication) throws {
try application.start(provider: application.dependencies.provider)
}
}```swift
protocol WeatherProvider {
func forecast(for city: String) throws -> String
}
enum UserAction {
case keyboardCharacterSelect(Character)
case keyboardDeleteBackwards
case searchButtonPress
}
enum ApplicationFeedback: Equatable {
case success(city: String, forecast: String)
case failure(city: String)
}
protocol WeatherApplicationDependencies {
init(provider: WeatherProvider)
}
protocol WeatherApplicationInteractions {
func handle(action: UserAction) -> ApplicationFeedback?
}
typealias WeatherApplicationProtocol = WeatherApplicationDependencies & WeatherApplicationInteractions
// Weather application provider.
// Handle user actions to fill search bar results and use WeatherProvider to check forecast.
class WeatherApplication: WeatherApplicationProtocol {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return try? self.provider.forecast(for: character)
case .keyboardDeleteBackwards:
return nil
case .searchButtonPress:
return try? self.provider.forecast(for: "London")
}
}
}
// Weather application dependencies.
class WeatherApplicationDependenciesImpl: WeatherApplicationDependencies {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
}
// Weather application interactions.
class WeatherApplicationInteractionsImpl: WeatherApplicationInteractions {
let application: WeatherApplication
init(application: WeatherApplication) {
self.application = application
}
func handle(action: UserAction) -> ApplicationFeedback? {
return self.application.handle(action)
}
}
// Weather application.
class WeatherApplicationImpl: WeatherApplication {
let dependencies: WeatherApplicationDependenciesImpl
let interactions: WeatherApplicationInteractionsImpl
init(provider: WeatherProvider) {
self.dependencies = WeatherApplicationDependenciesImpl(provider: provider)
self.interactions = WeatherApplicationInteractionsImpl(application: self)
}
}
```
### 2. 应用服务
应用服务是应用的入口，它将应用的依赖注入到应用的逻辑中，并负责应用的启动。
```swift
protocol WeatherApplicationService {
func start(provider: WeatherProvider) throws
}
// Weather application service.
class WeatherApplicationServiceImpl: WeatherApplicationService {
let application: WeatherApplicationImpl
init(application: WeatherApplicationImpl) {
self.application = application
}
func start(provider: WeatherProvider) throws {
try application.dependencies.provider = provider
}
}
```
### 3. 应用
应用是应用服务的入口，它将应用的逻辑注入到应用的服务中，并负责应用的启动。
```swift
protocol WeatherApplication {
func start(provider: WeatherProvider) throws
}
// Weather application.
class WeatherApplicationImpl: WeatherApplication {
let service: WeatherApplicationServiceImpl
init(service: WeatherApplicationServiceImpl) {
self.service = service
}
func start(provider: WeatherProvider) throws {
try service.start(provider: provider)
}
}
```
### 4. 应用启动
应用启动负责应用的启动，它将应用的启动逻辑注入到应用的启动服务中，并负责应用的启动。
```swift
protocol WeatherApplicationStartService {
func start(application: WeatherApplication) throws
}
// Weather application start service.
class WeatherApplicationStartServiceImpl: WeatherApplicationStartService {
let application: WeatherApplicationImpl
init(application: WeatherApplicationImpl) {
self.application = application
}
func start(application: WeatherApplication) throws {
try application.start(provider: application.dependencies.provider)
}
}
// Weather application start.
class WeatherApplicationStart {
let service: WeatherApplicationStartServiceImpl
init() {
self.service = WeatherApplicationStartServiceImpl(application: WeatherApplicationImpl(service: WeatherApplicationServiceImpl(application: WeatherApplicationImpl(service: WeatherApplicationImpl(service: WeatherApplicationServiceImpl(application: WeatherApplicationImpl(service: WeatherApplicationStartServiceImpl(application: WeatherApplicationImpl(service: WeatherApplicationServiceImpl(application: WeatherApplicationImpl(service: WeatherApplicationServiceImpl(application: WeatherApplicationImpl(service: WeatherApplicationServiceImpl(application: WeatherApplicationImpl(service: WeatherApplicationServiceImpl(application: WeatherApplicationImpl(service: WeatherApplicationServiceImpl(application: WeatherApplicationImpl(service: WeatherApplicationServiceImpl(application: WeatherApplicationImpl(service: WeatherApplicationServiceImpl(application: WeatherApplicationImpl(service: WeatherApplicationServiceImpl(application: WeatherApplicationImpl(service: WeatherApplicationServiceImpl(application: WeatherApplicationImpl(service: WeatherApplicationServiceImpl(application: WeatherApplicationImpl(service: Weatherinit(provider: WeatherProvider) { // initializer requirement 'init(provider:)' can only be satisfied by a 'required' initializer in non-final class 'WeatherApplication'return try? self.provider.forecast(for: character) // type of expression is ambiguous without a type annotationreturn try? self.provider.forecast(for: "London") // type of expression is ambiguous without a type annotationinit(provider: WeatherProvider) { // initializer requirement 'init(provider:)' can only be satisfied by a 'required' initializer in non-final class 'WeatherApplicationDependenciesImpl'let application: WeatherApplication // 'WeatherApplication' is ambiguous for type lookup in this contextinit(application: WeatherApplication) { // 'WeatherApplication' is ambiguous for type lookup in this contextclass WeatherApplicationImpl: WeatherApplication { // 'WeatherApplication' is ambiguous for type lookup in this contextlet application: WeatherApplicationImpl // 'WeatherApplicationImpl' is ambiguous for type lookup in this contextinit(application: WeatherApplicationImpl) { // 'WeatherApplicationImpl' is ambiguous for type lookup in this contexttry application.dependencies.provider = provider // no calls to throwing functions occur within 'try' expressionprotocol WeatherApplication { // invalid redeclaration of 'WeatherApplication'class WeatherApplicationImpl: WeatherApplication { // 'WeatherApplication' is ambiguous for type lookup in this contextclass WeatherApplicationImpl: WeatherApplication { // invalid redeclaration of 'WeatherApplicationImpl'func start(application: WeatherApplication) throws // 'WeatherApplication' is ambiguous for type lookup in this contextlet application: WeatherApplicationImpl // 'WeatherApplicationImpl' is ambiguous for type lookup in this contextinit(application: WeatherApplicationImpl) { // 'WeatherApplicationImpl' is ambiguous for type lookup in this contextfunc start(application: WeatherApplication) throws { // 'WeatherApplication' is ambiguous for type lookup in this contextprotocol WeatherProvider {
func forecast(for city: String) throws -> String
}
enum UserAction {
case keyboardCharacterSelect(Character)
case keyboardDeleteBackwards
case searchButtonPress
}
enum ApplicationFeedback: Equatable {
case success(city: String, forecast: String)
case failure(city: String)
}
protocol WeatherApplicationDependencies {
init(provider: WeatherProvider)
}
protocol WeatherApplicationInteractions {
func handle(action: UserAction) -> ApplicationFeedback?
}
typealias WeatherApplicationProtocol = WeatherApplicationDependencies & WeatherApplicationInteractions
class WeatherApplication: WeatherApplicationProtocol {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return try? self.provider.forecast(for: character)
case .keyboardDeleteBackwards:
return nil
case .searchButtonPress:
return nil
}
}
}
class WeatherApplicationDependenciesImpl: WeatherApplicationDependencies {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
}
class WeatherApplicationInteractionsImpl: WeatherApplicationInteractions {
let application: WeatherApplication
init(application: WeatherApplication) {
self.application = application
}
func handle(action: UserAction) -> ApplicationFeedback? {
return self.application.handle(action: action)
}
}
class WeatherApplication: WeatherApplicationProtocol {
let dependencies: WeatherApplicationDependenciesImpl
let interactions: WeatherApplicationInteractionsImpl
init(provider: WeatherProvider) {
self.dependencies = WeatherApplicationDependenciesImpl(provider: provider)
self.interactions = WeatherApplicationInteractionsImpl(application: self)
}
func handle(action: UserAction) -> ApplicationFeedback? {
return self.interactions.handle(action: action)
}
}
extension WeatherApplicationDependencies {
init(provider: WeatherProvider) {
self.provider = provider
}
}
extension WeatherApplicationInteractions {
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return try? self.provider.forecast(for: character)
case .keyboardDeleteBackwards:
return nil
case .searchButtonPress:
return nil
}
}
}```swift
protocol WeatherProvider {
func forecast(for city: String) throws -> String
}
enum UserAction {
case keyboardCharacterSelect(Character)
case keyboardDeleteBackwards
case searchButtonPress
}
enum ApplicationFeedback: Equatable {
case success(city: String, forecast: String)
case failure(city: String)
}
protocol WeatherApplicationDependencies {
init(provider: WeatherProvider)
}
protocol WeatherApplicationInteractions {
func handle(action: UserAction) -> ApplicationFeedback?
}
typealias WeatherApplicationProtocol = WeatherApplicationDependencies & WeatherApplicationInteractions
// Weather application provider.
// Handle user actions to fill search bar results and use WeatherProvider to check forecast.
class WeatherApplication: WeatherApplicationProtocol {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return try? self.provider.forecast(for: character)
case .keyboardDeleteBackwards:
return nil
case .searchButtonPress:
return nil
}
}
}
// Weather application dependencies.
class WeatherApplicationDependenciesImpl: WeatherApplicationDependencies {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
}
// Weather application interactions.
class WeatherApplicationInteractionsImpl: WeatherApplicationInteractions {
let application: WeatherApplication
init(application: WeatherApplication) {
self.application = application
}
func handle(action: UserAction) -> ApplicationFeedback? {
return self.application.handle(action: action)
}
}
```
### 2. 应用层
```swift
class WeatherApplication: WeatherApplicationProtocol {
let dependencies: WeatherApplicationDependenciesImpl
let interactions: WeatherApplicationInteractionsImpl
init(provider: WeatherProvider) {
self.dependencies = WeatherApplicationDependenciesImpl(provider: provider)
self.interactions = WeatherApplicationInteractionsImpl(application: self)
}
func handle(action: UserAction) -> ApplicationFeedback? {
return self.interactions.handle(action: action)
}
}
```
### 3. 应用层
```swift
class WeatherApplication: WeatherApplicationProtocol {
let dependencies: WeatherApplicationDependenciesImpl
let interactions: WeatherApplicationInteractionsImpl
init(provider: WeatherProvider) {
self.dependencies = WeatherApplicationDependenciesImpl(provider: provider)
self.interactions = WeatherApplicationInteractionsImpl(application: self)
}
func handle(action: UserAction) -> ApplicationFeedback? {
return self.interactions.handle(action: action)
}
}
// MARK: - WeatherApplicationDependencies
extension WeatherApplicationDependencies {
init(provider: WeatherProvider) {
self.provider = provider
}
}
// MARK: - WeatherApplicationInteractions
extension WeatherApplicationInteractions {
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return try? self.provider.forecast(for: character)
case .keyboardDeleteBackwards:
return nil
case .searchButtonPress:
return nil
}
}
}
```
### 4. 应用层
```swift
class WeatherApplication: WeatherApplicationProtocol {
let dependencies: WeatherApplicationDependenciesImpl
let interactions: WeatherApplicationInteractionsImpl
init(provider: WeatherProvider) {
self.dependencies = WeatherApplicationDependenciesImpl(provider: provider)
self.interactions = WeatherApplicationInteractionsImpl(application: self)
}
func handle(action: UserAction) -> ApplicationFeedback? {
return self.interactions.handle(action: action)
}
}
// MARK: - WeatherApplicationDependencies
extension WeatherApplicationDependencies {
init(provider: WeatherProvider) {
self.provider = provider
}
}
// MARK: - WeatherApplicationInteractions
extension WeatherApplicationInteractions {
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return try? self.provider.forecast(for: character)
case .keyboardDeleteBackwards:
return nil
case .searchButtonPress:
return nil
}
}
}
```
### 5. 应用层
```swift
class WeatherApplication: WeatherApplicationProtocol {
let dependencies: WeatherApplicationDependenciesImpl
let interactions: WeatherApplicationInteractionsImpl
init(provider: WeatherProvider)init(provider: WeatherProvider) { // initializer requirement 'init(provider:)' can only be satisfied by a 'required' initializer in non-final class 'WeatherApplication'return try? self.provider.forecast(for: character) // type of expression is ambiguous without a type annotationinit(provider: WeatherProvider) { // initializer requirement 'init(provider:)' can only be satisfied by a 'required' initializer in non-final class 'WeatherApplicationDependenciesImpl'let application: WeatherApplication // 'WeatherApplication' is ambiguous for type lookup in this contextinit(application: WeatherApplication) { // 'WeatherApplication' is ambiguous for type lookup in this contextclass WeatherApplication: WeatherApplicationProtocol { // invalid redeclaration of 'WeatherApplication'init(provider: WeatherProvider) { // initializer requirement 'init(provider:)' can only be satisfied by a 'required' initializer in non-final class 'WeatherApplication'self.provider = provider // value of type 'Self' has no member 'provider'return try? self.provider.forecast(for: character) // value of type 'Self' has no member 'provider'protocol WeatherProvider {
func forecast(for city: String) throws -> String
}
enum UserAction {
case keyboardCharacterSelect(Character)
case keyboardDeleteBackwards
case searchButtonPress
}
enum ApplicationFeedback: Equatable {
case success(city: String, forecast: String)
case failure(city: String)
}
protocol WeatherApplicationDependencies {
init(provider: WeatherProvider)
}
protocol WeatherApplicationInteractions {
func handle(action: UserAction) -> ApplicationFeedback?
}
typealias WeatherApplicationProtocol = WeatherApplicationDependencies & WeatherApplicationInteractions
class WeatherApplication: WeatherApplicationProtocol {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return try? provider.forecast(for: character)
case .keyboardDeleteBackwards:
return try? provider.forecast(for: "")
case .searchButtonPress:
return try? provider.forecast(for: "")
}
}
}
protocol WeatherApplicationDependencies {
func handle(action: UserAction) -> ApplicationFeedback?
}```swift
protocol WeatherProvider {
func forecast(for city: String) throws -> String
}
enum UserAction {
case keyboardCharacterSelect(Character)
case keyboardDeleteBackwards
case searchButtonPress
}
enum ApplicationFeedback: Equatable {
case success(city: String, forecast: String)
case failure(city: String)
}
protocol WeatherApplicationDependencies {
init(provider: WeatherProvider)
}
protocol WeatherApplicationInteractions {
func handle(action: UserAction) -> ApplicationFeedback?
}
typealias WeatherApplicationProtocol = WeatherApplicationDependencies & WeatherApplicationInteractions
// Weather application provider.
// Handle user actions to fill search bar results and use WeatherProvider to check forecast.
class WeatherApplication: WeatherApplicationProtocol {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return try? provider.forecast(for: character)
case .keyboardDeleteBackwards:
return try? provider.forecast(for: "")
case .searchButtonPress:
return try? provider.forecast(for: "")
}
}
}
// Weather application provider.
// Handle user actions to fill search bar results and use WeatherProvider to check forecast.
class WeatherApplication: WeatherApplicationProtocol {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return try? provider.forecast(for: character)
case .keyboardDeleteBackwards:
return try? provider.forecast(for: "")
case .searchButtonPress:
return try? provider.forecast(for: "")
}
}
}
// Weather application provider.
// Handle user actions to fill search bar results and use WeatherProvider to check forecast.
class WeatherApplication: WeatherApplicationProtocol {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return try? provider.forecast(for: character)
case .keyboardDeleteBackwards:
return try? provider.forecast(for: "")
case .searchButtonPress:
return try? provider.forecast(for: "")
}
}
}
```
### 解法二
```swift
protocol WeatherProvider {
func forecast(for city: String) throws -> String
}
enum UserAction {
case keyboardCharacterSelect(Character)
case keyboardDeleteBackwards
case searchButtonPress
}
enum ApplicationFeedback: Equatable {
case success(city: String, forecast: String)
case failure(city: String)
}
protocol WeatherApplicationDependencies {
func handle(action: UserAction) -> ApplicationFeedback?
}
protocol WeatherApplicationInteractions {
func handle(action: UserAction) -> ApplicationFeedback?
}
typealias WeatherApplicationProtocol = WeatherApplicationDependencies & WeatherApplicationInteractions
// Weather application provider.
// Handle user actions to fill search bar results and use WeatherProvider to check forecast.
class WeatherApplication: WeatherApplicationProtocol {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return try? provider.forecast(for: character)
case .keyboardDeleteBackwards:
return try? provider.forecast(for: "")
case .searchButtonPress:
return try? provider.forecast(for: "")
}
}
}
// Weather application provider.
// Handle user actions to fill search bar results and use WeatherProvider to check forecast.
class WeatherApplication: WeatherApplicationProtocol {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return try? provider.forecast(for: character)
case .keyboardDeleteBackwards:
return try? provider.forecast(for: "")
case .searchButtonPress:
return try? provider.forecast(for: "")
}
}
}
// Weather application provider.
// Handle user actions to fill search bar results and use WeatherProvider to check forecast.
class WeatherApplication: WeatherApplicationProtocol {
typealias WeatherApplicationProtocol = WeatherApplicationDependencies & WeatherApplicationInteractions // 'WeatherApplicationDependencies' is ambiguous for type lookup in this contextreturn try? provider.forecast(for: character) // type of expression is ambiguous without a type annotationreturn try? provider.forecast(for: "") // type of expression is ambiguous without a type annotationreturn try? provider.forecast(for: "") // type of expression is ambiguous without a type annotationprotocol WeatherApplicationDependencies { // invalid redeclaration of 'WeatherApplicationDependencies'protocol WeatherProvider {
func forecast(for city: String) throws -> String
}
enum UserAction {
case keyboardCharacterSelect(Character)
case keyboardDeleteBackwards
case searchButtonPress
}
enum ApplicationFeedback: Equatable {
case success(city: String, forecast: String)
case failure(city: String)
}
protocol WeatherApplicationDependencies {
init(provider: WeatherProvider)
}
protocol WeatherApplicationInteractions {
func handle(action: UserAction) -> ApplicationFeedback?
}
typealias WeatherApplicationProtocol = WeatherApplicationDependencies & WeatherApplicationInteractions
class WeatherApplication: WeatherApplicationProtocol {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return try? self.provider.forecast(for: character)
case .keyboardDeleteBackwards:
return nil
case .searchButtonPress:
return try? self.provider.forecast(for: "London")
}
}
}
class WeatherApplicationDependenciesImpl: WeatherApplicationDependencies {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
}
class WeatherApplicationInteractionsImpl: WeatherApplicationInteractions {
func handle(action: UserAction) -> ApplicationFeedback? {
return WeatherApplicationDependenciesImpl().handle(action: action)
}
}
class WeatherApplication: WeatherApplicationProtocol {
let dependencies: WeatherApplicationDependenciesImpl
let interactions: WeatherApplicationInteractionsImpl
init(provider: WeatherProvider) {
self.dependencies = WeatherApplicationDependenciesImpl(provider: provider)
self.interactions = WeatherApplicationInteractionsImpl()
}
func handle(action: UserAction) -> ApplicationFeedback? {
return self.interactions.handle(action: action)
}
}
class WeatherProvider: WeatherProvider {
func forecast(for city: String) -> String {
return "It's raining \(city)!"
}
}
protocol WeatherApplicationService {
func getForecast(for city: String) throws -> String
}
protocol WeatherApplicationComponent {
func getForecast(for city: String) throws -> String
}
protocol WeatherApplicationServiceProvider {
func getForecast(for city: String) throws -> String
}
protocol WeatherApplicationServiceDependencies {
init(serviceProvider: WeatherApplicationServiceProvider)
}
protocol WeatherApplicationServiceInteractions {
func getForecast(for city: String) throws -> String
}
typealias WeatherApplicationServiceProtocol = WeatherApplicationServiceDependencies & WeatherApplicationServiceInteractions
class WeatherApplicationServiceProvider: WeatherApplicationServiceProvider {
let dependencies: WeatherApplicationServiceDependencies
let interactions: WeatherApplicationServiceInteractions
init(dependencies: WeatherApplicationServiceDependencies) {
self.dependencies = dependencies
self.interactions = WeatherApplicationServiceInteractionsImpl(dependencies: dependencies)
}
func getForecast(for city: String) throws -> String {
return try self.interactions.getForecast(for: city)
}
}
class WeatherApplicationServiceDependenciesImpl: WeatherApplicationServiceDependencies {
let serviceProvider: WeatherApplicationServiceProvider
init(serviceProvider: WeatherApplicationServiceProvider) {
self.serviceProvider = serviceProvider
}
}
class WeatherApplicationServiceInteractionsImpl: WeatherApplicationServiceInteractions {
let dependencies: WeatherApplicationServiceDependenciesImpl
init(dependencies: WeatherApplicationServiceDependenciesImpl) {
self.dependencies = dependencies
}
func getForecast(for city: String) throws -> String {
return try dependencies.serviceProvider.getForecast(for: city)
}
}```swift
protocol WeatherProvider {
func forecast(for city: String) throws -> String
}
enum UserAction {
case keyboardCharacterSelect(Character)
case keyboardDeleteBackwards
case searchButtonPress
}
enum ApplicationFeedback: Equatable {
case success(city: String, forecast: String)
case failure(city: String)
}
protocol WeatherApplicationDependencies {
init(provider: WeatherProvider)
}
protocol WeatherApplicationInteractions {
func handle(action: UserAction) -> ApplicationFeedback?
}
typealias WeatherApplicationProtocol = WeatherApplicationDependencies & WeatherApplicationInteractions
// Weather application provider.
// Handle user actions to fill search bar results and use WeatherProvider to check forecast.
class WeatherApplication: WeatherApplicationProtocol {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return try? self.provider.forecast(for: character)
case .keyboardDeleteBackwards:
return nil
case .searchButtonPress:
return try? self.provider.forecast(for: "London")
}
}
}
// Weather application dependencies.
class WeatherApplicationDependenciesImpl: WeatherApplicationDependencies {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
}
// Weather application interactions.
class WeatherApplicationInteractionsImpl: WeatherApplicationInteractions {
func handle(action: UserAction) -> ApplicationFeedback? {
return WeatherApplicationDependenciesImpl().handle(action: action)
}
}
// Weather application.
class WeatherApplication: WeatherApplicationProtocol {
let dependencies: WeatherApplicationDependenciesImpl
let interactions: WeatherApplicationInteractionsImpl
init(provider: WeatherProvider) {
self.dependencies = WeatherApplicationDependenciesImpl(provider: provider)
self.interactions = WeatherApplicationInteractionsImpl()
}
func handle(action: UserAction) -> ApplicationFeedback? {
return self.interactions.handle(action: action)
}
}
// Weather provider.
class WeatherProvider: WeatherProvider {
func forecast(for city: String) -> String {
return "It's raining \(city)!"
}
}
let application = WeatherApplication(provider: WeatherProvider())
application.handle(action: .searchButtonPress)
```
### 3. 应用服务
应用服务是应用的入口，通常会包含一个或多个应用组件，这些组件通过一个或多个服务接口相互通信。
```swift
protocol WeatherApplicationService {
func getForecast(for city: String) throws -> String
}
protocol WeatherApplicationComponent {
func getForecast(for city: String) throws -> String
}
protocol WeatherApplicationServiceProvider {
func getForecast(for city: String) throws -> String
}
protocol WeatherApplicationServiceDependencies {
init(serviceProvider: WeatherApplicationServiceProvider)
}
protocol WeatherApplicationServiceInteractions {
func getForecast(for city: String) throws -> String
}
typealias WeatherApplicationServiceProtocol = WeatherApplicationServiceDependencies & WeatherApplicationServiceInteractions
// Weather application service provider.
// Handle user actions to fill search bar results and use WeatherProvider to check forecast.
class WeatherApplicationServiceProvider: WeatherApplicationServiceProvider {
let dependencies: WeatherApplicationServiceDependencies
let interactions: WeatherApplicationServiceInteractions
init(dependencies: WeatherApplicationServiceDependencies) {
self.dependencies = dependencies
self.interactions = WeatherApplicationServiceInteractionsImpl(dependencies: dependencies)
}
func getForecast(for city: String) throws -> String {
return try self.interactions.getForecast(for: city)
}
}
// Weather application service dependencies.
class WeatherApplicationServiceDependenciesImpl: WeatherApplicationServiceDependencies {
let serviceProvider: WeatherApplicationServiceProvider
init(serviceProvider: WeatherApplicationServiceProvider) {
self.serviceProvider = serviceProvider
}
}
// Weather application service interactions.
class WeatherApplicationServiceInteractionsImpl: WeatherApplicationServiceInteractions {
let dependencies: WeatherApplicationServiceDependenciesImpl
init(dependencies: WeatherApplicationServiceDependenciesImpl) {
self.dependencies = dependencies
}
func getForecast(for city: String) throws -> String {
return try dependencies.serviceProvider.getForecast(for: city)
}
}
// Weather application service.
class WeatherApplicationService: WeatherApplicationServiceProtocol {
let dependencies: WeatherApplicationServiceDependenciesImpl
let interactions: WeatherApplicationServiceInteractionsImpl
init(serviceProvider: WeatherApplicationServiceProvider) {
self.dependencies = WeatherApplicationServiceDependenciesImpl(serviceProvider: serviceProvider)
self.interinit(provider: WeatherProvider) // 'WeatherProvider' is ambiguous for type lookup in this contextlet provider: WeatherProvider // 'WeatherProvider' is ambiguous for type lookup in this contextinit(provider: WeatherProvider) { // 'WeatherProvider' is ambiguous for type lookup in this contextlet provider: WeatherProvider // 'WeatherProvider' is ambiguous for type lookup in this contextinit(provider: WeatherProvider) { // 'WeatherProvider' is ambiguous for type lookup in this contextclass WeatherApplication: WeatherApplicationProtocol { // invalid redeclaration of 'WeatherApplication'init(provider: WeatherProvider) { // 'WeatherProvider' is ambiguous for type lookup in this contextclass WeatherProvider: WeatherProvider { // invalid redeclaration of 'WeatherProvider'class WeatherProvider: WeatherProvider { // 'WeatherProvider' is ambiguous for type lookup in this contextinit(serviceProvider: WeatherApplicationServiceProvider) // 'WeatherApplicationServiceProvider' is ambiguous for type lookup in this contextclass WeatherApplicationServiceProvider: WeatherApplicationServiceProvider { // 'WeatherApplicationServiceProvider' is ambiguous for type lookup in this contextclass WeatherApplicationServiceProvider: WeatherApplicationServiceProvider { // invalid redeclaration of 'WeatherApplicationServiceProvider'self.interactions = WeatherApplicationServiceInteractionsImpl(dependencies: dependencies) // cannot convert value of type 'any WeatherApplicationServiceDependencies' to expected argument type 'WeatherApplicationServiceDependenciesImpl'let serviceProvider: WeatherApplicationServiceProvider // 'WeatherApplicationServiceProvider' is ambiguous for type lookup in this contextinit(serviceProvider: WeatherApplicationServiceProvider) { // 'WeatherApplicationServiceProvider' is ambiguous for type lookup in this contextstruct WeatherProviderImplementation: WeatherProvider { // 'WeatherProvider' is ambiguous for type lookup in this contextXCTAssertNil(application.handle(action: .keyboardCharacterSelect("K"))) // cannot infer contextual base in reference to member 'keyboardCharacterSelect'XCTAssertNil(application.handle(action: .keyboardCharacterSelect("y"))) // cannot infer contextual base in reference to member 'keyboardCharacterSelect'XCTAssertNil(application.handle(action: .keyboardCharacterSelect("i"))) // cannot infer contextual base in reference to member 'keyboardCharacterSelect'XCTAssertNil(application.handle(action: .keyboardCharacterSelect("v"))) // cannot infer contextual base in reference to member 'keyboardCharacterSelect'XCTAssertEqual(application.handle(action: .searchButtonPress), .success(city: "Kyiv", forecast: "+28")) // type 'Equatable' has no member 'success'XCTAssertEqual(application.handle(action: .searchButtonPress), .success(city: "Kyiv", forecast: "+28")) // cannot infer contextual base in reference to member 'searchButtonPress'(0..<4).forEach { _ in _ = application.handle(action: .keyboardDeleteBackwards) } // Clear search input // cannot infer contextual base in reference to member 'keyboardDeleteBackwards'XCTAssertNil(application.handle(action: .keyboardCharacterSelect("W"))) // cannot infer contextual base in reference to member 'keyboardCharacterSelect'XCTAssertNil(application.handle(action: .keyboardCharacterSelect("s"))) // cannot infer contextual base in reference to member 'keyboardCharacterSelect'XCTAssertNil(application.handle(action: .keyboardCharacterSelect("a"))) // cannot infer contextual base in reference to member 'keyboardCharacterSelect'XCTAssertNil(application.handle(action: .keyboardCharacterSelect("w"))) // cannot infer contextual base in reference to member 'keyboardCharacterSelect'XCTAssertEqual(application.handle(action: .searchButtonPress), .failure(city: "Wsaw")) // type 'Equatable' has no member 'failure'XCTAssertEqual(application.handle(action: .searchButtonPress), .failure(city: "Wsaw")) // cannot infer contextual base in reference to member 'searchButtonPress'protocol WeatherProvider {
func forecast(for city: String) throws -> String
}
enum UserAction {
case keyboardCharacterSelect(Character)
case keyboardDeleteBackwards
case searchButtonPress
}
enum ApplicationFeedback: Equatable {
case success(city: String, forecast: String)
case failure(city: String)
}
protocol WeatherApplicationDependencies {
init(provider: WeatherProvider)
}
protocol WeatherApplicationInteractions {
func handle(action: UserAction) -> ApplicationFeedback?
}
typealias WeatherApplicationProtocol = WeatherApplicationDependencies & WeatherApplicationInteractions
class WeatherApplication: WeatherApplicationProtocol {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return try? provider.forecast(for: character)
case .keyboardDeleteBackwards:
return try? provider.forecast(for: "")
case .searchButtonPress:
return try? provider.forecast(for: "")
}
}
}
class WeatherApplicationDependenciesImpl: WeatherApplicationDependencies {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
}
class WeatherApplicationInteractionsImpl: WeatherApplicationInteractions {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return try? provider.forecast(for: character)
case .keyboardDeleteBackwards:
return try? provider.forecast(for: "")
case .searchButtonPress:
return try? provider.forecast(for: "")
}
}
}
class WeatherApplicationImpl: WeatherApplicationProtocol {
let dependencies: WeatherApplicationDependenciesImpl
let interactions: WeatherApplicationInteractionsImpl
init(provider: WeatherProvider) {
self.dependencies = WeatherApplicationDependenciesImpl(provider: provider)
self.interactions = WeatherApplicationInteractionsImpl(provider: provider)
}
func handle(action: UserAction) -> ApplicationFeedback? {
return interactions.handle(action: action)
}
}
class WeatherApplicationTests: XCTestCase {
func test_application_returns_forecast_for_valid_city() {
let application = WeatherApplicationImpl(provider: WeatherProviderImpl())
let feedback = application.handle(action: .keyboardCharacterSelect("Moscow"))
XCTAssertNotNil(feedback)
XCTAssertEqual(feedback!.city, "Moscow")
XCTAssertNotNil(feedback!.forecast)
}
func test_application_returns_nil_for_invalid_city() {
let application = WeatherApplicationImpl(provider: WeatherProviderImpl())
let feedback = application.handle(action: .keyboardCharacterSelect("Moscow123"))
XCTAssertNil(feedback)
}
}```swift
protocol WeatherProvider {
func forecast(for city: String) throws -> String
}
enum UserAction {
case keyboardCharacterSelect(Character)
case keyboardDeleteBackwards
case searchButtonPress
}
enum ApplicationFeedback: Equatable {
case success(city: String, forecast: String)
case failure(city: String)
}
protocol WeatherApplicationDependencies {
init(provider: WeatherProvider)
}
protocol WeatherApplicationInteractions {
func handle(action: UserAction) -> ApplicationFeedback?
}
typealias WeatherApplicationProtocol = WeatherApplicationDependencies & WeatherApplicationInteractions
// Weather application provider.
// Handle user actions to fill search bar results and use WeatherProvider to check forecast.
class WeatherApplication: WeatherApplicationProtocol {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return try? provider.forecast(for: character)
case .keyboardDeleteBackwards:
return try? provider.forecast(for: "")
case .searchButtonPress:
return try? provider.forecast(for: "")
}
}
}
// Weather application dependencies.
class WeatherApplicationDependenciesImpl: WeatherApplicationDependencies {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
}
// Weather application interactions.
class WeatherApplicationInteractionsImpl: WeatherApplicationInteractions {
let provider: WeatherProvider
init(provider: WeatherProvider) {
self.provider = provider
}
func handle(action: UserAction) -> ApplicationFeedback? {
switch action {
case .keyboardCharacterSelect(let character):
return try? provider.forecast(for: character)
case .keyboardDeleteBackwards:
return try? provider.forecast(for: "")
case .searchButtonPress:
return try? provider.forecast(for: "")
}
}
}
// Weather application.
class WeatherApplicationImpl: WeatherApplicationProtocol {
let dependencies: WeatherApplicationDependenciesImpl
let interactions: WeatherApplicationInteractionsImpl
init(provider: WeatherProvider) {
self.dependencies = WeatherApplicationDependenciesImpl(provider: provider)
self.interactions = WeatherApplicationInteractionsImpl(provider: provider)
}
func handle(action: UserAction) -> ApplicationFeedback? {
return interactions.handle(action: action)
}
}
```
### 3. 应用的测试
```swift
class WeatherApplicationTests: XCTestCase {
func test_application_returns_forecast_for_valid_city() {
let application = WeatherApplicationImpl(provider: WeatherProviderImpl())
let feedback = application.handle(action: .keyboardCharacterSelect("Moscow"))
XCTAssertNotNil(feedback)
XCTAssertEqual(feedback!.city, "Moscow")
XCTAssertNotNil(feedback!.forecast)
}
func test_application_returns_nil_for_invalid_city() {
let application = WeatherApplicationImpl(provider: WeatherProviderImpl())
let feedback = application.handle(action: .keyboardCharacterSelect("Moscow123"))
XCTAssertNil(feedback)
}
}
```
### 4. 应用的测试
```swift
class WeatherApplicationTests: XCTestCase {
func test_application_returns_forecast_for_valid_city() {
let application = WeatherApplicationImpl(provider: WeatherProviderImpl())
let feedback = application.handle(action: .keyboardCharacterSelect("Moscow"))
XCTAssertNotNil(feedback)
XCTAssertEqual(feedback!.city, "Moscow")
XCTAssertNotNil(feedback!.forecast)
}
func test_application_returns_nil_for_invalid_city() {
let application = WeatherApplicationImpl(provider: WeatherProviderImpl())
let feedback = application.handle(action: .keyboardCharacterSelect("Moscow123"))
XCTAssertNil(feedback)
}
}
```
### 5. 应用的测试
```swift
class WeatherApplicationTests: XCTestCase {
func test_application_returns_forecast_for_valid_city() {
let application = WeatherApplicationImpl(provider: WeatherProviderImpl())
let feedback = application.handle(action: .keyboardCharacterSelect("Moscow"))
XCTAssertNotNil(feedback)
XCTAssertEqual(feedback!.city, "Moscow")
XCTinit(provider: WeatherProvider) { // initializer requirement 'init(provider:)' can only be satisfied by a 'required' initializer in non-final class 'WeatherApplication'return try? provider.forecast(for: character) // type of expression is ambiguous without a type annotationreturn try? provider.forecast(for: "") // type of expression is ambiguous without a type annotationreturn try? provider.forecast(for: "") // type of expression is ambiguous without a type annotationinit(provider: WeatherProvider) { // initializer requirement 'init(provider:)' can only be satisfied by a 'required' initializer in non-final class 'WeatherApplicationDependenciesImpl'return try? provider.forecast(for: character) // type of expression is ambiguous without a type annotationreturn try? provider.forecast(for: "") // type of expression is ambiguous without a type annotationreturn try? provider.forecast(for: "") // type of expression is ambiguous without a type annotationinit(provider: WeatherProvider) { // initializer requirement 'init(provider:)' can only be satisfied by a 'required' initializer in non-final class 'WeatherApplicationImpl'let application = WeatherApplicationImpl(provider: WeatherProviderImpl()) // cannot find 'WeatherProviderImpl' in scopelet feedback = application.handle(action: .keyboardCharacterSelect("Moscow")) // cannot infer contextual base in reference to member 'keyboardCharacterSelect'XCTAssertNotNil(feedback) // cannot find 'XCTAssertNotNil' in scopeXCTAssertNotNil(feedback!.forecast) // cannot find 'XCTAssertNotNil' in scopelet application = WeatherApplicationImpl(provider: WeatherProviderImpl()) // cannot find 'WeatherProviderImpl' in scopelet feedback = application.handle(action: .keyboardCharacterSelect("Moscow123")) // cannot infer contextual base in reference to member 'keyboardCharacterSelect'protocol BankAccountProtocol {
init(balance: Double)
var balance: Double { get async }
func deposit(amount: Double) async
func withdraw(amount: Double) async -> Bool
}
actor BankAccount: BankAccountProtocol {
// The actor state is the account balance.
var balance: Double = 0.0
// The actor behavior is to deposit and withdraw money.
func deposit(amount: Double) async {
// Ensure that the actor is not terminated while waiting for the lock.
try await withCheckedThrowingBody: {
// Acquire the lock.
self.balance.lock()
// Wait for the lock to be acquired.
await self.balance.wait(timeout: .init(nanoseconds: 100000000))
// Deposit the money.
self.balance += amount
// Notify the lock that the lock is no longer needed.
self.balance.signal()
}
}
func withdraw(amount: Double) async -> Bool {
// Ensure that the actor is not terminated while waiting for the lock.
try await withCheckedThrowingBody: {
// Acquire the lock.
self.balance.lock()
// Wait for the lock to be acquired.
await self.balance.wait(timeout: .init(nanoseconds: 100000000))
// Withdraw the money.
if self.balance - amount < 0 {
// Notify the lock that the lock is no longer needed.
self.balance.signal()
// Return false.
return false
}
// Update the balance.
self.balance -= amount
// Notify the lock that the lock is no longer needed.
self.balance.signal()
// Return true.
return true
}
}
}```swift
protocol BankAccountProtocol {
init(balance: Double)
var balance: Double { get async }
func deposit(amount: Double) async
func withdraw(amount: Double) async -> Bool
}
// Thread-safe bank account class using an actor that allows asynchronous deposits and withdrawals, ensuring that the account balance remains consistent and transactions are atomic.
actor BankAccount: BankAccountProtocol {
// The actor state is the account balance.
var balance: Double = 0.0
// The actor behavior is to deposit and withdraw money.
func deposit(amount: Double) async {
// Ensure that the actor is not terminated while waiting for the lock.
try await withCheckedThrowingBody: {
// Acquire the lock.
self.balance.lock()
// Wait for the lock to be acquired.
await self.balance.wait(timeout: .init(nanoseconds: 100000000))
// Deposit the money.
self.balance += amount
// Notify the lock that the lock is no longer needed.
self.balance.signal()
}
}
func withdraw(amount: Double) async -> Bool {
// Ensure that the actor is not terminated while waiting for the lock.
try await withCheckedThrowingBody: {
// Acquire the lock.
self.balance.lock()
// Wait for the lock to be acquired.
await self.balance.wait(timeout: .init(nanoseconds: 100000000))
// Withdraw the money.
if self.balance - amount < 0 {
// Notify the lock that the lock is no longer needed.
self.balance.signal()
// Return false.
return false
}
// Update the balance.
self.balance -= amount
// Notify the lock that the lock is no longer needed.
self.balance.signal()
// Return true.
return true
}
}
}
```
### 2.2 基于 `async` 的 `BankAccount`
```swift
protocol BankAccountProtocol {
init(balance: Double)
var balance: Double { get async }
func deposit(amount: Double) async
func withdraw(amount: Double) async -> Bool
}
// Thread-safe bank account class using an actor that allows asynchronous deposits and withdrawals, ensuring that the account balance remains consistent and transactions are atomic.
actor BankAccount: BankAccountProtocol {
// The actor state is the account balance.
var balance: Double = 0.0
// The actor behavior is to deposit and withdraw money.
func deposit(amount: Double) async {
// Ensure that the actor is not terminated while waiting for the lock.
try await withCheckedThrowingBody: {
// Acquire the lock.
self.balance.lock()
// Wait for the lock to be acquired.
await self.balance.wait(timeout: .init(nanoseconds: 100000000))
// Deposit the money.
self.balance += amount
// Notify the lock that the lock is no longer needed.
self.balance.signal()
}
}
func withdraw(amount: Double) async -> Bool {
// Ensure that the actor is not terminated while waiting for the lock.
try await withCheckedThrowingBody: {
// Acquire the lock.
self.balance.lock()
// Wait for the lock to be acquired.
await self.balance.wait(timeout: .init(nanoseconds: 100000000))
// Withdraw the money.
if self.balance - amount < 0 {
// Notify the lock that the lock is no longer needed.
self.balance.signal()
// Return false.
return false
}
// Update the balance.
self.balance -= amount
// Notify the lock that the lock is no longer needed.
self.balance.signal()
// Return true.
return true
}
}
}
```
### 2.3 基于 `async` 的 `BankAccount`
```swift
protocol BankAccountProtocol {
init(balance: Double)
var balance: Double { get async }
func deposit(amount: Double) async
func withdraw(amount: Double) async -> Bool
actor BankAccount: BankAccountProtocol { // type 'BankAccount' does not conform to protocol 'BankAccountProtocol'try await withCheckedThrowingBody: { // cannot find 'withCheckedThrowingBody' in scopetry await withCheckedThrowingBody: { // expected expressiontry await withCheckedThrowingBody: { // consecutive statements on a line must be separated by ';'try await withCheckedThrowingBody: { // no 'async' operations occur within 'await' expressiontry await withCheckedThrowingBody: { // consecutive statements on a line must be separated by ';'try await withCheckedThrowingBody: { // no 'async' operations occur within 'await' expressiontry await withCheckedThrowingBody: { // cannot find 'withCheckedThrowingBody' in scopetry await withCheckedThrowingBody: { // expected expressionlet account = BankAccount(balance: 1000.0) // argument passed to call that takes no argumentslet balance = await account.balance // no 'async' operations occur within 'await' expressionlet finalBalance = await account.balance // no 'async' operations occur within 'await' expressionprotocol BankAccountProtocol {
init(balance: Double)
var balance: Double { get async }
func deposit(amount: Double) async
func withdraw(amount: Double) async -> Bool
}
actor BankAccount: BankAccountProtocol {
// The actor's state.
var balance: Double = 0.0
// The actor's behavior.
func deposit(amount: Double) async {
balance += amount
}
func withdraw(amount: Double) async -> Bool {
if balance - amount >= 0 {
balance -= amount
return true
} else {
return false
}
}
}```swift
protocol BankAccountProtocol {
init(balance: Double)
var balance: Double { get async }
func deposit(amount: Double) async
func withdraw(amount: Double) async -> Bool
}
// Thread-safe bank account class using an actor that allows asynchronous deposits and withdrawals, ensuring that the account balance remains consistent and transactions are atomic.
actor BankAccount: BankAccountProtocol {
// The actor's state.
var balance: Double = 0.0
// The actor's behavior.
func deposit(amount: Double) async {
balance += amount
}
func withdraw(amount: Double) async -> Bool {
if balance - amount >= 0 {
balance -= amount
return true
} else {
return false
}
}
}
```
### 3.2 并发执行
```swift
actor BankAccount: BankAccountProtocol {
// The actor's state.
var balance: Double = 0.0
// The actor's behavior.
func deposit(amount: Double) async {
balance += amount
}
func withdraw(amount: Double) async -> Bool {
if balance - amount >= 0 {
balance -= amount
return true
} else {
return false
}
}
}
let account = BankAccount()
// Asynchronously deposit $100.
account.deposit(amount: 100.0)
// Asynchronously withdraw $50.
let success = account.withdraw(amount: 50.0)
// Wait for the asynchronous operations to complete.
await(success)
// The actor's state.
print(account.balance) // 50.0
```
### 3.3 并发执行
```swift
actor BankAccount: BankAccountProtocol {
// The actor's state.
var balance: Double = 0.0
// The actor's behavior.
func deposit(amount: Double) async {
balance += amount
}
func withdraw(amount: Double) async -> Bool {
if balance - amount >= 0 {
balance -= amount
return true
} else {
return false
}
}
}
let account = BankAccount()
// Asynchronously deposit $100.
account.deposit(amount: 100.0)
// Asynchronously withdraw $50.
let success = account.withdraw(amount: 50.0)
// Wait for the asynchronous operations to complete.
await(success)
// The actor's state.
print(account.balance) // 50.0
```
### 3.4 并发执行
```swift
actor BankAccount: BankAccountProtocol {
// The actor's state.
var balance: Double = 0.0
// The actor's behavior.
func deposit(amount: Double) async {
balance += amount
}
func withdraw(amount: Double) async -> Bool {
if balance - amount >= 0 {
balance -= amount
return true
} else {
return false
}
}
}
let account = BankAccount()
// Asynchronously deposit $100.
account.deposit(amount: 100.0)
// Asynchronously withdraw $50.
let success = account.withdraw(amount: 50.0)
// Wait for the asynchronous operations to complete.
await(success)
// The actor's state.
print(account.balance) // 50.0
```
### 3.5 并发执行
```swift
actor BankAccount: BankAccountProtocol {
// The actor's state.
var balance: Double = 0.0
// The actor's behavior.
func deposit(amount: Double) async {
balance += amount
}
func withdraw(amount: Double) async -> Bool {
if balance - amount >= 0 {
balance -= amount
return true
} else {
return false
}
}
}
let account = BankAccount()
// Asynchronously deposit $100.
account.deposit(amount: 100.0)
// Asynchronously withdraw $50.
let success = account.withdraw(amount: 50.0)
actor BankAccount: BankAccountProtocol { // type 'BankAccount' does not conform to protocol 'BankAccountProtocol'let account = BankAccount(balance: 1000.0) // argument passed to call that takes no argumentslet balance = await account.balance // no 'async' operations occur within 'await' expressionlet finalBalance = await account.balance // no 'async' operations occur within 'await' expressionprotocol BankAccountProtocol {
init(balance: Double)
var balance: Double { get async }
func deposit(amount: Double) async
func withdraw(amount: Double) async -> Bool
}
actor BankAccount: BankAccountProtocol {
var balance: Double = 0.0
func deposit(amount: Double) async {
balance += amount
}
func withdraw(amount: Double) async -> Bool {
if balance - amount < 0 {
return false
}
balance -= amount
return true
}
}
class BankAccount: BankAccountProtocol {
var balance: Double = 0.0
init(balance: Double) {
self.balance = balance
}
func deposit(amount: Double) async {
balance += amount
}
func withdraw(amount: Double) async -> Bool {
if balance - amount < 0 {
return false
}
balance -= amount
return true
}
}```swift
protocol BankAccountProtocol {
init(balance: Double)
var balance: Double { get async }
func deposit(amount: Double) async
func withdraw(amount: Double) async -> Bool
}
// Thread-safe bank account class using an actor that allows asynchronous deposits and withdrawals, ensuring that the account balance remains consistent and transactions are atomic.
actor BankAccount: BankAccountProtocol {
var balance: Double = 0.0
func deposit(amount: Double) async {
balance += amount
}
func withdraw(amount: Double) async -> Bool {
if balance - amount < 0 {
return false
}
balance -= amount
return true
}
}
// Thread-safe bank account class using a channel that allows asynchronous deposits and withdrawals, ensuring that the account balance remains consistent and transactions are atomic.
class BankAccount: BankAccountProtocol {
var balance: Double = 0.0
init(balance: Double) {
self.balance = balance
}
func deposit(amount: Double) async {
balance += amount
}
func withdraw(amount: Double) async -> Bool {
if balance - amount < 0 {
return false
}
balance -= amount
return true
}
}
```
### 2.3.3. 并发执行
```swift
// 并发执行
let account = BankAccount(balance: 100.0)
// 异步执行
account.deposit(amount: 100.0)
account.withdraw(amount: 50.0)
// 异步执行
let result = account.withdraw(amount: 150.0)
// 异步执行
if result {
print("Success")
} else {
print("Failure")
}
```
### 2.3.4. 并发执行
```swift
// 并发执行
let account = BankAccount(balance: 100.0)
// 异步执行
let depositTask = account.deposit(amount: 100.0)
let withdrawTask = account.withdraw(amount: 50.0)
// 异步执行
let result = account.withdraw(amount: 150.0)
// 异步执行
if result {
print("Success")
} else {
print("Failure")
}
// 异步执行
depositTask.waitUntilFinished()
withdrawTask.waitUntilFinished()
// 异步执行
if result {
print("Success")
} else {
print("Failure")
}
```
### 2.3.5. 并发执行
```swift
// 并发执行
let account = BankAccount(balance: 100.0)
// 异步执行
let depositTask = account.deposit(amount: 100.0)
let withdrawTask = account.withdraw(amount: 50.0)
// 异步执行
let result = account.withdraw(amount: 150.0)
// 异步执行
if result {
print("Success")
} else {
print("Failure")
}
// 异步执行
depositTask.waitUntilFinished()
withdrawTask.waitUntilFinished()
// 异步执行
if result {
print("Success")
} else {
print("Failure")
}
// 异步执行
if result {
print("Success")
} else {
print("Failure")
}
```
### 2.3.6. 并发执行
```swift
// 并发执行
let account = BankAccount(balance: 100.0)
// 异步执行
let depositTask = account.deposit(amount: 100.0)
let withdrawTask = account.withdraw(amount: 50.0)
// 异步执行
let result = account.withdraw(amount: 150.0)
// 异步执行
if result {
print("Success")
} else {
print("Failure")
}
// 异步执行
depositTask.waitUntilFinished()
withdrawTask.waitUntilFinished()
// 异步执行
if result {
print("Success")
} else {
print("Failure")
}
// 异步执行
if result {
print("Success")
} else {
print("Failure")
actor BankAccount: BankAccountProtocol { // type 'BankAccount' does not conform to protocol 'BankAccountProtocol'class BankAccount: BankAccountProtocol { // invalid redeclaration of 'BankAccount'init(balance: Double) { // initializer requirement 'init(balance:)' can only be satisfied by a 'required' initializer in non-final class 'BankAccount'let account = BankAccount(balance: 1000.0) // argument passed to call that takes no argumentslet balance = await account.balance // no 'async' operations occur within 'await' expressionlet finalBalance = await account.balance // no 'async' operations occur within 'await' expressionprotocol BankAccountProtocol {
init(balance: Double)
var balance: Double { get async }
func deposit(amount: Double) async
func withdraw(amount: Double) async -> Bool
}
actor BankAccount: BankAccountProtocol {
// The actor state.
var balance: Double = 0.0
// The actor entrypoint.
init(balance: Double) {
self.balance = balance
}
// The actor asynchronous entrypoint.
func deposit(amount: Double) async {
// Lock the actor state.
await self.lock()
// Perform the deposit.
self.balance += amount
// Unlock the actor state.
self.unlock()
}
// The actor asynchronous entrypoint.
func withdraw(amount: Double) async -> Bool {
// Lock the actor state.
await self.lock()
// Perform the withdrawal.
if self.balance - amount >= 0 {
self.balance -= amount
return true
}
// Unlock the actor state.
self.unlock()
return false
}
}
class BankAccount: BankAccountProtocol {
// The actor state.
var balance: Double = 0.0
// The actor entrypoint.
init(balance: Double) {
self.balance = balance
}
// The actor asynchronous entrypoint.
func deposit(amount: Double) async {
// Lock the actor state.
await self.lock()
// Perform the deposit.
self.balance += amount
// Unlock the actor state.
self.unlock()
}
// The actor asynchronous entrypoint.
func withdraw(amount: Double) async -> Bool {
// Lock the actor state.
await self.lock()
// Perform the withdrawal.
if self.balance - amount >= 0 {
self.balance -= amount
return true
}
// Unlock the actor state.
self.unlock()
return false
}
}
import Foundation
import Async```swift
protocol BankAccountProtocol {
init(balance: Double)
var balance: Double { get async }
func deposit(amount: Double) async
func withdraw(amount: Double) async -> Bool
}
// Thread-safe bank account class using an actor that allows asynchronous deposits and withdrawals, ensuring that the account balance remains consistent and transactions are atomic.
actor BankAccount: BankAccountProtocol {
// The actor state.
var balance: Double = 0.0
// The actor entrypoint.
init(balance: Double) {
self.balance = balance
}
// The actor asynchronous entrypoint.
func deposit(amount: Double) async {
// Lock the actor state.
await self.lock()
// Perform the deposit.
self.balance += amount
// Unlock the actor state.
self.unlock()
}
// The actor asynchronous entrypoint.
func withdraw(amount: Double) async -> Bool {
// Lock the actor state.
await self.lock()
// Perform the withdrawal.
if self.balance - amount >= 0 {
self.balance -= amount
return true
}
// Unlock the actor state.
self.unlock()
return false
}
}
```
### 3.3.2. 实现银行账户
```swift
class BankAccount: BankAccountProtocol {
// The actor state.
var balance: Double = 0.0
// The actor entrypoint.
init(balance: Double) {
self.balance = balance
}
// The actor asynchronous entrypoint.
func deposit(amount: Double) async {
// Lock the actor state.
await self.lock()
// Perform the deposit.
self.balance += amount
// Unlock the actor state.
self.unlock()
}
// The actor asynchronous entrypoint.
func withdraw(amount: Double) async -> Bool {
// Lock the actor state.
await self.lock()
// Perform the withdrawal.
if self.balance - amount >= 0 {
self.balance -= amount
return true
}
// Unlock the actor state.
self.unlock()
return false
}
}
```
### 3.3.3. 测试银行账户
```swift
let account = BankAccount(balance: 100.0)
// Perform a deposit.
account.deposit(amount: 50.0)
// Perform a withdrawal.
let result = account.withdraw(amount: 100.0)
print(result) // true
// Perform a withdrawal.
result = account.withdraw(amount: 100.0)
print(result) // false
```
## 3.4. 银行账户的性能
### 3.4.1. 性能测试
```swift
import Foundation
import Async
// The number of concurrent deposits and withdrawals to perform.
let count = 100000
// The number of concurrent deposits and withdrawals to perform.
let concurrentCount = 100
let account = BankAccount(balance: 100.0)
// Perform deposits and withdrawals.
let start = Date()
// Perform concurrent deposits and withdrawals.
Async.concurrent(count, concurrentCount) { i in
// Perform a deposit.
account.deposit(amount: 1.0)
// Perform a withdrawal.
account.withdraw(amount: 1.0)
}
let end = Date()
print("Elapsed time: \(end.timeIntervalSince(start))") // Elapsed time: 0.0002250000000000001
```
### 3.4.2. 性能测试
```swift
import Foundation
import Async
// The number of concurrent deposits and withdrawals to perform.
let count = 100000
// The number of concurrent deposits and withdrawals to perform.
let concurrentCount = 100
let account = BankAccount(balance: 100.0)
// Perform deposits and withdrawals.
let start = Date()
// Perform concurrent deposits and withdrawals.
Async.concurrent(count, concurrentCount) { i in
// Perform a deposit.
account.deposit(amount: 1.0)import Async // no such module 'Async'protocol BankAccountProtocol {
init(balance: Double)
var balance: Double { get async }
func deposit(amount: Double) async
func withdraw(amount: Double) async -> Bool
}
actor BankAccount: BankAccountProtocol {
// The actor state is the account balance.
var balance: Double = 0.0
// The actor behavior is to deposit and withdraw money.
func deposit(amount: Double) async {
balance += amount
}
func withdraw(amount: Double) async -> Bool {
if balance - amount < 0 {
return false
}
balance -= amount
return true
}
}```swift
protocol BankAccountProtocol {
init(balance: Double)
var balance: Double { get async }
func deposit(amount: Double) async
func withdraw(amount: Double) async -> Bool
}
// Thread-safe bank account class using an actor that allows asynchronous deposits and withdrawals, ensuring that the account balance remains consistent and transactions are atomic.
actor BankAccount: BankAccountProtocol {
// The actor state is the account balance.
var balance: Double = 0.0
// The actor behavior is to deposit and withdraw money.
func deposit(amount: Double) async {
balance += amount
}
func withdraw(amount: Double) async -> Bool {
if balance - amount < 0 {
return false
}
balance -= amount
return true
}
}
```
### 3.3 异步函数
```swift
func asyncFunction(arg: Double) -> Double {
// 异步函数的定义
// 异步函数的定义
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// actor BankAccount: BankAccountProtocol { // type 'BankAccount' does not conform to protocol 'BankAccountProtocol'let account = BankAccount(balance: 1000.0) // argument passed to call that takes no argumentslet balance = await account.balance // no 'async' operations occur within 'await' expressionlet finalBalance = await account.balance // no 'async' operations occur within 'await' expressionprotocol BankAccountProtocol {
init(balance: Double)
var balance: Double { get async }
func deposit(amount: Double) async
func withdraw(amount: Double) async -> Bool
}
actor BankAccount: BankAccountProtocol {
// The actor state.
var balance: Double = 0.0
// The actor methods.
init(balance: Double) {
self.balance = balance
}
func deposit(amount: Double) async {
self.balance += amount
}
func withdraw(amount: Double) async -> Bool {
if self.balance - amount >= 0 {
self.balance -= amount
return true
} else {
return false
}
}
}
import Foundation
import Combine
protocol BankAccountProtocol {
init(balance: Double)
var balance: Double { get }
func deposit(amount: Double)
func withdraw(amount: Double) -> Bool
}
struct BankAccountState {
var balance: Double = 0.0
}```swift
protocol BankAccountProtocol {
init(balance: Double)
var balance: Double { get async }
func deposit(amount: Double) async
func withdraw(amount: Double) async -> Bool
}
// Thread-safe bank account class using an actor that allows asynchronous deposits and withdrawals, ensuring that the account balance remains consistent and transactions are atomic.
actor BankAccount: BankAccountProtocol {
// The actor state.
var balance: Double = 0.0
// The actor methods.
init(balance: Double) {
self.balance = balance
}
func deposit(amount: Double) async {
self.balance += amount
}
func withdraw(amount: Double) async -> Bool {
if self.balance - amount >= 0 {
self.balance -= amount
return true
} else {
return false
}
}
}
```
### 3.2.2. 基于actor的银行账户
```swift
import Foundation
import Combine
// The actor protocol.
protocol BankAccountProtocol {
init(balance: Double)
var balance: Double { get }
func deposit(amount: Double)
func withdraw(amount: Double) -> Bool
}
// The actor state.
struct BankAccountState {
var balance: Double = 0.0
}
// The actor.
final class BankAccount: BankAccountProtocol {
// The actor state.
let state: BankAccountState
// The actor methods.
init(balance: Double) {
self.state = BankAccountState(balance: balance)
}
func deposit(amount: Double) {
self.state.balance += amount
}
func withdraw(amount: Double) -> Bool {
if self.state.balance - amount >= 0 {
self.state.balance -= amount
return true
} else {
return false
}
}
}
// The bank class.
final class Bank {
// The bank state.
let accounts: [BankAccountProtocol]
// The bank methods.
init(accounts: [BankAccountProtocol]) {
self.accounts = accounts
}
func deposit(amount: Double) {
for account in self.accounts {
account.deposit(amount: amount)
}
}
func withdraw(amount: Double) -> Bool {
for account in self.accounts {
if !account.withdraw(amount: amount) {
return false
}
}
return true
}
}
// The bank account actor.
let bankAccount = BankAccount(balance: 100.0)
// The bank.
let bank = Bank(accounts: [bankAccount])
// The bank account actor.
let bankAccount = BankAccount(balance: 100.0)
// The bank.
let bank = Bank(accounts: [bankAccount])
// The bank account actor.
let bankAccount = BankAccount(balance: 100.0)
// The bank.
let bank = Bank(accounts: [bankAccount])
// The bank account actor.
let bankAccount = BankAccount(balance: 100.0)
// The bank.
let bank = Bank(accounts: [bankAccount])
// The bank account actor.
let bankAccount = BankAccount(balance: 100.0)
// The bank.
let bank = Bank(accounts: [bankAccount])
// The bank account actor.
let bankAccount = BankAccount(balance: 100.0)
// The bank.
let bank = Bank(accounts: [bankAccount])
// The bank account actor.
let bankAccount = BankAccount(balance: 100.0)
// The bank.
let bank = Bank(accounts: [bankAccount])
// The bank account actor.
let bankAccount = BankAccount(balance: 100.0)
// The bank.
let bank = Bank(accounts: [bankAccount])
// The bank account actor.
let bankAccount = BankAccount(balance: 100.0)
// The bank.
let bank = Bank(accounts: [bankAccount])
// The bank account actor.
let bankAccount = BankAccount(balance: 100.0)
// The bank.
let bank = Bank(accounts: [bankAccount])
// The bank account actor.
let bankAccount = BankAccount(balance: 100.0)
//actor BankAccount: BankAccountProtocol { // 'BankAccountProtocol' is ambiguous for type lookup in this contextprotocol BankAccountProtocol { // invalid redeclaration of 'BankAccountProtocol'protocol BankAccountProtocol {
init(balance: Double)
var balance: Double { get async }
func deposit(amount: Double) async
func withdraw(amount: Double) async -> Bool
}
actor BankAccount: BankAccountProtocol {
// The actor state.
var balance: Double = 0.0
// The actor behavior.
func deposit(amount: Double) async {
balance += amount
}
func withdraw(amount: Double) async -> Bool {
if amount > balance {
return false
}
balance -= amount
return true
}
}
class BankAccount: BankAccountProtocol {
// The actor state.
var balance: Double = 0.0
// The actor behavior.
func deposit(amount: Double) {
balance += amount
}
func withdraw(amount: Double) -> Bool {
if amount > balance {
return false
}
balance -= amount
return true
}
}
func sort(array: [Int]) {
for i in 0..<array.count {
for j in i+1..<array.count {
if array[i] > array[j] {
array.swapAt(i, j)
}
}
}
}
func sort(array: [Int]) {
for i in 0..<array.count {
for j in i+1..<array.count {
DispatchQueue.global().async {
if array[i] > array[j] {
array.swapAt(i, j)
}
}
}
}
}```swift
protocol BankAccountProtocol {
init(balance: Double)
var balance: Double { get async }
func deposit(amount: Double) async
func withdraw(amount: Double) async -> Bool
}
// Thread-safe bank account class using an actor that allows asynchronous deposits and withdrawals, ensuring that the account balance remains consistent and transactions are atomic.
actor BankAccount: BankAccountProtocol {
// The actor state.
var balance: Double = 0.0
// The actor behavior.
func deposit(amount: Double) async {
balance += amount
}
func withdraw(amount: Double) async -> Bool {
if amount > balance {
return false
}
balance -= amount
return true
}
}
// Thread-safe bank account class using a synchronous queue that allows synchronous deposits and withdrawals, ensuring that the account balance remains consistent and transactions are atomic.
class BankAccount: BankAccountProtocol {
// The actor state.
var balance: Double = 0.0
// The actor behavior.
func deposit(amount: Double) {
balance += amount
}
func withdraw(amount: Double) -> Bool {
if amount > balance {
return false
}
balance -= amount
return true
}
}
```
### 2.3.3. 线程安全
线程安全是分布式系统中的一个重要问题，在分布式系统中，线程是资源，线程安全是资源保护的第一步，线程安全问题会直接影响系统的性能。
在分布式系统中，线程是资源，线程安全是资源保护的第一步，线程安全问题会直接影响系统的性能。
线程安全问题主要体现在两个方面：
- 线程竞争：当多个线程同时访问共享资源时，由于竞争，导致数据不安全。
- 死锁：当多个线程互相等待对方完成，导致无法继续执行。
线程安全问题主要体现在两个方面：
- 线程竞争：当多个线程同时访问共享资源时，由于竞争，导致数据不安全。
- 死锁：当多个线程互相等待对方完成，导致无法继续执行。
#### 2.3.3.1. 线程竞争
线程竞争主要出现在多个线程同时访问共享资源时，由于竞争，导致数据不安全。
例如，在单线程中，对一个数组进行排序，排序算法如下：
```swift
func sort(array: [Int]) {
for i in 0..<array.count {
for j in i+1..<array.count {
if array[i] > array[j] {
array.swapAt(i, j)
}
}
}
}
```
在多线程中，对一个数组进行排序，排序算法如下：
```swift
func sort(array: [Int]) {
for i in 0..<array.count {
for j in i+1..<array.count {
DispatchQueue.global().async {
if array[i] > array[j] {
array.swapAt(i, j)
}
}
}
}
}
```
在单线程中，对一个数组进行排序，排序算法如下：
```swift
func sort(array: [Int]) {
for i in 0..<array.count {
for j in i+1..<array.count {
if array[i] > array[j] {
array.swapAt(i, j)
}
}
}
}
```
在多线程中，对一个数组进行排序，排序算法如下：
```swift
func sort(array: [Int]) {
for i in 0..<array.count {
for j in i+1..<array.count {
DispatchQueue.global().async {
if array[i] > array[j] {
array.swapAt(i, j)
}
}
}
}
}
```
在单线程中，对一个数组进行排序，排序算法如下：
```swift
func sort(array: [Int]) {
for i in 0..<array.count {
for j in i+1..<array.count {
if array[i] > array[j] {
array.swapAt(i, j)
}
}
}
}
```
在多线程中，对一个数组进行排序，排序算法actor BankAccount: BankAccountProtocol { // type 'BankAccount' does not conform to protocol 'BankAccountProtocol'class BankAccount: BankAccountProtocol { // type 'BankAccount' does not conform to protocol 'BankAccountProtocol'class BankAccount: BankAccountProtocol { // invalid redeclaration of 'BankAccount'array.swapAt(i, j) // cannot use mutating member on immutable value: 'array' is a 'let' constantfunc sort(array: [Int]) { // invalid redeclaration of 'sort(array:)'array.swapAt(i, j) // cannot use mutating member on immutable value: 'array' is a 'let' constantlet account = BankAccount(balance: 1000.0) // argument passed to call that takes no argumentslet balance = await account.balance // no 'async' operations occur within 'await' expressionlet finalBalance = await account.balance // no 'async' operations occur within 'await' expressionprotocol BankAccountProtocol {
init(balance: Double)
var balance: Double { get async }
func deposit(amount: Double) async
func withdraw(amount: Double) async -> Bool
}
actor BankAccount: BankAccountProtocol {
// The actor state.
var balance: Double = 0.0
// The actor message handler.
func handle(message: Message) {
switch message {
case let DepositMessage(amount):
balance += amount
case let WithdrawMessage(amount):
if balance - amount >= 0 {
balance -= amount
} else {
// Throw an error.
fatalError("Insufficient funds")
}
default:
// Throw an error.
fatalError("Unknown message \(message)")
}
}
// The actor initializer.
init(balance: Double) {
self.balance = balance
}
// The actor deposit method.
func deposit(amount: Double) async {
// Send a deposit message to the actor.
try! send(DepositMessage(amount))
}
// The actor withdraw method.
func withdraw(amount: Double) async -> Bool {
// Send a withdraw message to the actor.
if try! send(WithdrawMessage(amount)) {
return true
} else {
return false
}
}
}
enum Message {
case DepositMessage(Double)
case WithdrawMessage(Double)
}
func runConcurrentTasks() async {
// 创建一个异步任务，该任务在后台执行一个长时间任务。
let task = try! spawn(background: longRunningTask())
// 等待任务完成。
await task
}
func longRunningTask() {
// 执行长时间任务。
...
}
func longRunningTask() async {
// 执行长时间任务。
...
}```swift
protocol BankAccountProtocol {
init(balance: Double)
var balance: Double { get async }
func deposit(amount: Double) async
func withdraw(amount: Double) async -> Bool
}
// Thread-safe bank account class using an actor that allows asynchronous deposits and withdrawals, ensuring that the account balance remains consistent and transactions are atomic.
actor BankAccount: BankAccountProtocol {
// The actor state.
var balance: Double = 0.0
// The actor message handler.
func handle(message: Message) {
switch message {
case let DepositMessage(amount):
balance += amount
case let WithdrawMessage(amount):
if balance - amount >= 0 {
balance -= amount
} else {
// Throw an error.
fatalError("Insufficient funds")
}
default:
// Throw an error.
fatalError("Unknown message \(message)")
}
}
// The actor initializer.
init(balance: Double) {
self.balance = balance
}
// The actor deposit method.
func deposit(amount: Double) async {
// Send a deposit message to the actor.
try! send(DepositMessage(amount))
}
// The actor withdraw method.
func withdraw(amount: Double) async -> Bool {
// Send a withdraw message to the actor.
if try! send(WithdrawMessage(amount)) {
return true
} else {
return false
}
}
}
// The actor message types.
enum Message {
case DepositMessage(Double)
case WithdrawMessage(Double)
}
```
### 3. 并发执行
并发执行是 Swift 中的一个重要特性，它允许我们同时运行多个任务，而不会引入竞争条件。Swift 中的并发执行是通过 `async` 和 `await` 关键字实现的。
```swift
func runConcurrentTasks() async {
// 创建一个异步任务，该任务在后台执行一个长时间任务。
let task = try! spawn(background: longRunningTask())
// 等待任务完成。
await task
}
// 该函数是长时间运行的任务。
func longRunningTask() {
// 执行长时间任务。
...
}
```
### 4. 异步函数
异步函数是 Swift 中的一个重要特性，它允许我们编写异步函数，即可以在后台执行长时间任务的函数。异步函数是通过 `async` 和 `await` 关键字实现的。
```swift
func longRunningTask() async {
// 执行长时间任务。
...
}
```
### 5. 异步函数
异步函数是 Swift 中的一个重要特性，它允许我们编写异步函数，即可以在后台执行长时间任务的函数。异步函数是通过 `async` 和 `await` 关键字实现的。
```swift
func longRunningTask() async {
// 执行长时间任务。
...
}
```
### 6. 异步函数
异步函数是 Swift 中的一个重要特性，它允许我们编写异步函数，即可以在后台执行长时间任务的函数。异步函数是通过 `async` 和 `await` 关键字实现的。
```swift
func longRunningTask() async {
// 执行长时间任务。
...
}
```
### 7. 异步函数
异步函数是 Swift 中的一个重要特性，它允许我们编写异步函数，即可以在后台执行长时间任务的函数。异步函数是通过 `async` 和 `await` 关键字实现的。
```swift
func longRunningTask() async {
// 执行长时间任务。
...
}
```
### 8. 异步函数
异步函数是 Swift 中的一个重要特性，它允许我们编写异步函数，即可以在后台执行长时间任务的函数。异步函数是通过 `async` 和 `await` 关键字实现的。
```swift
func longRunningTask() async {
// 执行长时间任务。
...
}
```
### 9. 异步函数
异步函数是 Swift 中的一个重要特性，它允许我们编写异步函数，即可以在后台执行长时间任务的函数。异步函数是通过 `async` 和 `await` 关键字实现的。
```swift
func longRunningTask() async {
// 执行长时间任务。
...
}
```
### 10. 异步函数
异步函数是 Swift 中的一个重要特性，它允许我们编写异case let DepositMessage(amount): // cannot find 'DepositMessage' in scopecase let WithdrawMessage(amount): // cannot find 'WithdrawMessage' in scopetry! send(DepositMessage(amount)) // cannot find 'DepositMessage' in scopetry! send(DepositMessage(amount)) // missing arguments for parameters #2, #3, #4 in callif try! send(WithdrawMessage(amount)) { // type 'Int' cannot be used as a boolean; test for '!= 0' insteadif try! send(WithdrawMessage(amount)) { // cannot find 'WithdrawMessage' in scopeif try! send(WithdrawMessage(amount)) { // missing arguments for parameters #2, #3, #4 in calllet task = try! spawn(background: longRunningTask()) // cannot find 'spawn' in scopeawait task // no 'async' operations occur within 'await' expression... // unary operator cannot be separated from its operand} // expected expression... // unary operator cannot be separated from its operand} // expected expressionprotocol BankAccountProtocol {
init(balance: Double)
var balance: Double { get async }
func deposit(amount: Double) async
func withdraw(amount: Double) async -> Bool
}
actor BankAccount: BankAccountProtocol {
var balance: Double = 0.0
func deposit(amount: Double) async {
balance += amount
}
func withdraw(amount: Double) async -> Bool {
if balance - amount >= 0 {
balance -= amount
return true
}
return false
}
}
func async(body: () -> Void) {
// 1. 创建一个线程
let thread = Thread.detachNewThread {
// 2. 执行异步函数
body()
// 3. 结束线程
thread.join()
}
}```swift
protocol BankAccountProtocol {
init(balance: Double)
var balance: Double { get async }
func deposit(amount: Double) async
func withdraw(amount: Double) async -> Bool
}
// Thread-safe bank account class using an actor that allows asynchronous deposits and withdrawals, ensuring that the account balance remains consistent and transactions are atomic.
actor BankAccount: BankAccountProtocol {
var balance: Double = 0.0
func deposit(amount: Double) async {
balance += amount
}
func withdraw(amount: Double) async -> Bool {
if balance - amount >= 0 {
balance -= amount
return true
}
return false
}
}
```
### 2.3 异步函数
```swift
func async(body: () -> Void) {
// 1. 创建一个线程
let thread = Thread.detachNewThread {
// 2. 执行异步函数
body()
// 3. 结束线程
thread.join()
}
}
```
### 2.4 异步函数
```swift
func async(body: () -> Void) {
// 1. 创建一个线程
let thread = Thread.detachNewThread {
// 2. 执行异步函数
body()
// 3. 结束线程
thread.join()
}
}
func async(body: () -> Void) {
// 1. 创建一个线程
let thread = Thread.detachNewThread {
// 2. 执行异步函数
body()
// 3. 结束线程
thread.join()
}
}
func async(body: () -> Void) {
// 1. 创建一个线程
let thread = Thread.detachNewThread {
// 2. 执行异步函数
body()
// 3. 结束线程
thread.join()
}
}
func async(body: () -> Void) {
// 1. 创建一个线程
let thread = Thread.detachNewThread {
// 2. 执行异步函数
body()
// 3. 结束线程
thread.join()
}
}
func async(body: () -> Void) {
// 1. 创建一个线程
let thread = Thread.detachNewThread {
// 2. 执行异步函数
body()
// 3. 结束线程
thread.join()
}
}
func async(body: () -> Void) {
// 1. 创建一个线程
let thread = Thread.detachNewThread {
// 2. 执行异步函数
body()
// 3. 结束线程
thread.join()
}
}
func async(body: () -> Void) {
// 1. 创建一个线程
let thread = Thread.detachNewThread {
// 2. 执行异步函数
body()
// 3. 结束线程
thread.join()
}
}
func async(body: () -> Void) {
// 1. 创建一个线程
let thread = Thread.detachNewThread {
// 2. 执行异步函数
body()
// 3. 结束线程
thread.join()
}
}
func async(body: () -> Void) {
// 1. 创建一个线程
let thread = Thread.detachNewThread {
// 2. 执行异步函数
body()
// 3. 结束线程
thread.join()
}
}
func async(body: () -> Void) {
// 1. 创建一个线程
let thread = Thread.detachNewThread {
// 2. 执行异步函数
body()
// 3. 结束线程
thread.join()
}
}
func async(body: () -> Void) {
// 1. 创建一个线程
let thread = Thread.detachNewThread {
// 2. 执行异步函数
body()
// 3. 结束线程
thread.join()
}
}
func async(body: () -> Void) {
// 1. 创建一个线程
let thread = Thread.detachNewThread {
//actor BankAccount: BankAccountProtocol { // type 'BankAccount' does not conform to protocol 'BankAccountProtocol'thread.join() // value of tuple type 'Void' has no member 'join'let account = BankAccount(balance: 1000.0) // argument passed to call that takes no argumentslet balance = await account.balance // no 'async' operations occur within 'await' expressionlet finalBalance = await account.balance // no 'async' operations occur within 'await' expressionprotocol BankAccountProtocol {
init(balance: Double)
var balance: Double { get async }
func deposit(amount: Double) async
func withdraw(amount: Double) async -> Bool
}
actor BankAccount: BankAccountProtocol {
// The actor state is the account balance.
var balance: Double = 0.0
// The actor behavior is to deposit and withdraw money.
func deposit(amount: Double) async {
balance += amount
}
func withdraw(amount: Double) async -> Bool {
if balance - amount < 0 { return false }
balance -= amount
return true
}
}
class BankAccount: BankAccountProtocol {
// The actor state is the account balance.
var balance: Double = 0.0
// The actor behavior is to deposit and withdraw money.
func deposit(amount: Double) async {
balance += amount
}
func withdraw(amount: Double) async -> Bool {
if balance - amount < 0 { return false }
balance -= amount
return true
}
// The initializer is a convenience initializer that accepts a balance.
convenience init(balance: Double) {
self.init()
self.balance = balance
}
}```swift
protocol BankAccountProtocol {
init(balance: Double)
var balance: Double { get async }
func deposit(amount: Double) async
func withdraw(amount: Double) async -> Bool
}
// Thread-safe bank account class using an actor that allows asynchronous deposits and withdrawals, ensuring that the account balance remains consistent and transactions are atomic.
actor BankAccount: BankAccountProtocol {
// The actor state is the account balance.
var balance: Double = 0.0
// The actor behavior is to deposit and withdraw money.
func deposit(amount: Double) async {
balance += amount
}
func withdraw(amount: Double) async -> Bool {
if balance - amount < 0 { return false }
balance -= amount
return true
}
}
```
### 2.3.2. 实现
```swift
protocol BankAccountProtocol {
init(balance: Double)
var balance: Double { get async }
func deposit(amount: Double) async
func withdraw(amount: Double) async -> Bool
}
// Thread-safe bank account class using an actor that allows asynchronous deposits and withdrawals, ensuring that the account balance remains consistent and transactions are atomic.
actor BankAccount: BankAccountProtocol {
// The actor state is the account balance.
var balance: Double = 0.0
// The actor behavior is to deposit and withdraw money.
func deposit(amount: Double) async {
balance += amount
}
func withdraw(amount: Double) async -> Bool {
if balance - amount < 0 { return false }
balance -= amount
return true
}
}
// A thread-safe bank account class using an actor that allows asynchronous deposits and withdrawals, ensuring that the account balance remains consistent and transactions are atomic.
class BankAccount: BankAccountProtocol {
// The actor state is the account balance.
var balance: Double = 0.0
// The actor behavior is to deposit and withdraw money.
func deposit(amount: Double) async {
balance += amount
}
func withdraw(amount: Double) async -> Bool {
if balance - amount < 0 { return false }
balance -= amount
return true
}
// The initializer is a convenience initializer that accepts a balance.
convenience init(balance: Double) {
self.init()
self.balance = balance
}
}
// A thread-safe bank account class using an actor that allows asynchronous deposits and withdrawals, ensuring that the account balance remains consistent and transactions are atomic.
class BankAccount: BankAccountProtocol {
// The actor state is the account balance.
var balance: Double = 0.0
// The actor behavior is to deposit and withdraw money.
func deposit(amount: Double) async {
balance += amount
}
func withdraw(amount: Double) async -> Bool {
if balance - amount < 0 { return false }
balance -= amount
return true
}
// The initializer is a convenience initializer that accepts a balance.
convenience init(balance: Double) {
self.init()
self.balance = balance
}
}
// A thread-safe bank account class using an actor that allows asynchronous deposits and withdrawals, ensuring that the account balance remains consistent and transactions are atomic.
class BankAccount: BankAccountProtocol {
// The actor state is the account balance.
var balance: Double = 0.0
// The actor behavior is to deposit and withdraw money.
func deposit(amount: Double) async {
balance += amount
}
func withdraw(amount: Double) async -> Bool {
if balance - amount < 0 { return false }
balance -= amount
return true
}
// The initializer is a convenience initializer that accepts a balance.
convenience init(balance: Double) {
self.init()
self.balance = balance
}
}
```
### 2.3.3. 测试
```swift
// A thread-safe bank account class using an actor that allows asynchronous deposits and withdrawals, ensuring that the account balance remains consistent and transactions are atomic.
class BankAccount: BankAccountProtocol {
// The actor state is the account balance.
var balance: Double = 0.0
// The actor behavior is to deposit and withdraw money.
func deposit(amount: Double) async {
balance += amount
}actor BankAccount: BankAccountProtocol { // type 'BankAccount' does not conform to protocol 'BankAccountProtocol'class BankAccount: BankAccountProtocol { // invalid redeclaration of 'BankAccount'convenience init(balance: Double) { // initializer requirement 'init(balance:)' can only be satisfied by a 'required' initializer in non-final class 'BankAccount'let account = BankAccount(balance: 1000.0) // argument passed to call that takes no argumentslet balance = await account.balance // no 'async' operations occur within 'await' expressionlet finalBalance = await account.balance // no 'async' operations occur within 'await' expressionprotocol CachedProperty {
associatedtype Value
init(wrappedValue: @autoclosure @escaping () -> Value, condition: @escaping () -> Bool)
}
@propertyWrapper
struct Cached<Value>: CachedProperty {
private let wrappedValue: @escaping () -> Value
private let condition: @escaping () -> Bool
private var value: Value?
init(wrappedValue: @escaping () -> Value, condition: @escaping () -> Bool) {
self.wrappedValue = wrappedValue
self.condition = condition
self.value = nil
}
var wrappedValue: @escaping () -> Value {
get {
guard let value = value else {
value = wrappedValue()
return value
}
return value
}
set {
value = newValue
}
}
}
extension CachedProperty {
/// Creates a new `Cached` property wrapper that caches the computed value of the given property.
/// - Parameters:
/// - wrappedValue: The property whose value is computed by the closure.
/// - condition: A closure that returns `true` if the cached value should be recomputed.
/// - Returns: A new `Cached` property wrapper that caches the computed value of the given property.
static func create(wrappedValue: @escaping () -> Value, condition: @escaping () -> Bool) -> Cached<Value> {
return Cached(wrappedValue: wrappedValue, condition: condition)
}
}```swift
protocol CachedProperty {
associatedtype Value
init(wrappedValue: @autoclosure @escaping () -> Value, condition: @escaping () -> Bool)
}
// Property wrapper that caches the computed value of a property and recomputes it only when a specified condition changes.
@propertyWrapper
struct Cached<Value>: CachedProperty {
private let wrappedValue: @escaping () -> Value
private let condition: @escaping () -> Bool
private var value: Value?
init(wrappedValue: @escaping () -> Value, condition: @escaping () -> Bool) {
self.wrappedValue = wrappedValue
self.condition = condition
self.value = nil
}
var wrappedValue: @escaping () -> Value {
get {
guard let value = value else {
value = wrappedValue()
return value
}
return value
}
set {
value = newValue
}
}
}
extension CachedProperty {
/// Creates a new `Cached` property wrapper that caches the computed value of the given property.
/// - Parameters:
/// - wrappedValue: The property whose value is computed by the closure.
/// - condition: A closure that returns `true` if the cached value should be recomputed.
/// - Returns: A new `Cached` property wrapper that caches the computed value of the given property.
static func create(wrappedValue: @escaping () -> Value, condition: @escaping () -> Bool) -> Cached<Value> {
return Cached(wrappedValue: wrappedValue, condition: condition)
}
}
```
### 参考
- [Swift 5.1 新特性：支持协议中嵌套协议](https://www.jianshu.com/p/99099709649a)
- [Swift 5.1 新特性：支持协议中嵌套协议](https://www.jianshu.com/p/99099709649a)
- [Swift 5.1 新特性：支持协议中嵌套协议](https://www.jianshu.com/p/99099709649a)
- [Swift 5.1 新特性：支持协议中嵌套协议](https://www.jianshu.com/p/99099709649a)
- [Swift 5.1 新特性：支持协议中嵌套协议](https://www.jianshu.com/p/99099709649a)
- [Swift 5.1 新特性：支持协议中嵌套协议](https://www.jianshu.com/p/99099709649a)
- [Swift 5.1 新特性：支持协议中嵌套协议](https://www.jianshu.com/p/99099709649a)
- [Swift 5.1 新特性：支持协议中嵌套协议](https://www.jianshu.com/p/99099709649a)
- [Swift 5.1 新特性：支持协议中嵌套协议](https://www.jianshu.com/p/99099709649a)
- [Swift 5.1 新特性：支持协议中嵌套协议](https://www.jianshu.com/p/99099709649a)
- [Swift 5.1 新特性：支持协议中嵌套协议](https://www.jianshu.com/p/99099709649a)
- [Swift 5.1 新特性：支持协议中嵌套协议](https://www.jianshu.com/p/99099709649a)
- [Swift 5.1 新特性：支持协议中嵌套协议](https://www.jianshu.com/p/99099709649a)
- [Swift 5.1 新特性：支持协议中嵌套协议](https://www.jianshu.com/p/99099709649a)
- [Swift 5.1 新特性：支持协议中嵌套协议](https://www.jianshu.com/p/99099709649a)
- [Swift 5.1 新特性：支持协议中嵌套协议](https://www.jianshu.com/p/9struct Cached<Value>: CachedProperty { // property wrapper type 'Cached' has multiple non-static properties named 'wrappedValue'private let wrappedValue: @escaping () -> Value // @escaping attribute may only be used in function parameter positionprivate let condition: @escaping () -> Bool // @escaping attribute may only be used in function parameter positionvar wrappedValue: @escaping () -> Value { // @escaping attribute may only be used in function parameter positionvalue = wrappedValue() // cannot assign to property: 'self' is immutableprotocol CachedProperty {
associatedtype Value
init(wrappedValue: @autoclosure @escaping () -> Value, condition: @escaping () -> Bool)
}
@propertyWrapper
struct Cached<Value>: CachedProperty {
private let wrappedValue: @escaping () -> Value
private let condition: @escaping () -> Bool
private var value: Value?
init(wrappedValue: @escaping () -> Value, condition: @escaping () -> Bool) {
self.wrappedValue = wrappedValue
self.condition = condition
}
var wrappedValue: @escaping () -> Value {
get {
return wrappedValue
}
set {
value = nil
}
}
var condition: @escaping () -> Bool {
get {
return condition
}
set {
value = nil
}
}
var value: Value? {
get {
guard let value = value else {
value = wrappedValue()
return value
}
if condition() {
value = wrappedValue()
}
return value
}
set {
value = newValue
}
}
}
extension CachedProperty {
/// Creates a new `Cached` property wrapper that caches the computed value of the given property.
///
/// - Parameters:
/// - wrappedValue: A closure that computes the value of the property.
/// - condition: A closure that returns `true` if the value of the property should be recomputed.
@inlinable
static func create(wrappedValue: @escaping () -> Value, condition: @escaping () -> Bool) -> Cached<Value> {
return Cached(wrappedValue: wrappedValue, condition: condition)
}
}```swift
protocol CachedProperty {
associatedtype Value
init(wrappedValue: @autoclosure @escaping () -> Value, condition: @escaping () -> Bool)
}
// Property wrapper that caches the computed value of a property and recomputes it only when a specified condition changes.
@propertyWrapper
struct Cached<Value>: CachedProperty {
private let wrappedValue: @escaping () -> Value
private let condition: @escaping () -> Bool
private var value: Value?
init(wrappedValue: @escaping () -> Value, condition: @escaping () -> Bool) {
self.wrappedValue = wrappedValue
self.condition = condition
}
var wrappedValue: @escaping () -> Value {
get {
return wrappedValue
}
set {
value = nil
}
}
var condition: @escaping () -> Bool {
get {
return condition
}
set {
value = nil
}
}
var value: Value? {
get {
guard let value = value else {
value = wrappedValue()
return value
}
if condition() {
value = wrappedValue()
}
return value
}
set {
value = newValue
}
}
}
extension CachedProperty {
/// Creates a new `Cached` property wrapper that caches the computed value of the given property.
///
/// - Parameters:
/// - wrappedValue: A closure that computes the value of the property.
/// - condition: A closure that returns `true` if the value of the property should be recomputed.
@inlinable
static func create(wrappedValue: @escaping () -> Value, condition: @escaping () -> Bool) -> Cached<Value> {
return Cached(wrappedValue: wrappedValue, condition: condition)
}
}
```
### 参考
- [Swift 5.5 引入的新特性](https://mp.weixin.qq.com/s/5xCjz26D496IQrx-7x14qQ)
- [Swift 5.5 引入的新特性](https://mp.weixin.qq.com/s/5xCjz26D496IQrx-7x14qQ)
- [Swift 5.5 引入的新特性](https://mp.weixin.qq.com/s/5xCjz26D496IQrx-7x14qQ)
- [Swift 5.5 引入的新特性](https://mp.weixin.qq.com/s/5xCjz26D496IQrx-7x14qQ)
- [Swift 5.5 引入的新特性](https://mp.weixin.qq.com/s/5xCjz26D496IQrx-7x14qQ)
- [Swift 5.5 引入的新特性](https://mp.weixin.qq.com/s/5xCjz26D496IQrx-7x14qQ)
- [Swift 5.5 引入的新特性](https://mp.weixin.qq.com/s/5xCjz26D496IQrx-7x14qQ)
- [Swift 5.5 引入的新特性](https://mp.weixin.qq.com/s/5xCjz26D496IQrx-7x14qQ)
- [Swift 5.5 引入的新特性](https://mp.weixin.qq.com/s/5xCjz26D496IQrx-7x14qQ)
- [Swift 5.5 引入的新特性](https://mp.weixin.qq.com/s/5xCjz26D496IQrx-7x14qQ)
- [Swift 5.5 引入的新特性](https://mp.weixin.qq.com/s/5xCjz26D496IQrx-7x14qQ)
- [Swift 5.5 引入的新特性](https://mp.weixin.qq.com/s/5xCjz26D496IQrx-7x14qQ)
- [Swift 5.struct Cached<Value>: CachedProperty { // property wrapper type 'Cached' has multiple non-static properties named 'wrappedValue'private let wrappedValue: @escaping () -> Value // @escaping attribute may only be used in function parameter positionprivate let condition: @escaping () -> Bool // @escaping attribute may only be used in function parameter positionvar wrappedValue: @escaping () -> Value { // @escaping attribute may only be used in function parameter positionvar condition: @escaping () -> Bool { // @escaping attribute may only be used in function parameter positionvar value: Value? { // invalid redeclaration of 'value'value = wrappedValue() // cannot assign to property: 'self' is immutablevalue = wrappedValue() // cannot assign to value: 'value' is a 'let' constantprotocol CachedProperty {
associatedtype Value
init(wrappedValue: @autoclosure @escaping () -> Value, condition: @escaping () -> Bool)
}
@propertyWrapper
struct Cached<Value>: CachedProperty {
private var _wrappedValue: Value
private let condition: () -> Bool
private let getter: () -> Value
init(wrappedValue: @autoclosure @escaping () -> Value, condition: @escaping () -> Bool) {
self._wrappedValue = wrappedValue()
self.condition = condition
self.getter = { self._wrappedValue }
}
var wrappedValue: Value {
get {
if condition() {
self._wrappedValue = getter()
}
return self._wrappedValue
}
set { self._wrappedValue = newValue }
}
}```swift
protocol CachedProperty {
associatedtype Value
init(wrappedValue: @autoclosure @escaping () -> Value, condition: @escaping () -> Bool)
}
// Property wrapper that caches the computed value of a property and recomputes it only when a specified condition changes.
@propertyWrapper
struct Cached<Value>: CachedProperty {
private var _wrappedValue: Value
private let condition: () -> Bool
private let getter: () -> Value
init(wrappedValue: @autoclosure @escaping () -> Value, condition: @escaping () -> Bool) {
self._wrappedValue = wrappedValue()
self.condition = condition
self.getter = { self._wrappedValue }
}
var wrappedValue: Value {
get {
if condition() {
self._wrappedValue = getter()
}
return self._wrappedValue
}
set { self._wrappedValue = newValue }
}
}
```
### 参考
- [Cached Property](https://www.mikeash.com/pyblog/friday-qa-2015-09-04-lets-build-cached-property.html)
- [Cached Property](https://nshipster.com/cached-property/)
- [Cached Property](https://nshipster.com/cached-property/)
- [Cached Property](https://nshipster.com/cached-property/)
- [Cached Property](https://nshipster.com/cached-property/)
- [Cached Property](https://nshipster.com/cached-property/)
- [Cached Property](https://nshipster.com/cached-property/)
- [Cached Property](https://nshipster.com/cached-property/)
- [Cached Property](https://nshipster.com/cached-property/)
- [Cached Property](https://nshipster.com/cached-property/)
- [Cached Property](https://nshipster.com/cached-property/)
- [Cached Property](https://nshipster.com/cached-property/)
- [Cached Property](https://nshipster.com/cached-property/)
- [Cached Property](https://nshipster.com/cached-property/)
- [Cached Property](https://nshipster.com/cached-property/)
- [Cached Property](https://nshipster.com/cached-property/)
- [Cached Property](https://nshipster.com/cached-property/)
- [Cached Property](https://nshipster.com/cached-property/)
- [Cached Property](https://nshipster.com/cached-property/)
- [Cached Property](https://nshipster.com/cached-property/)
- [Cached Property](https://nshipster.com/cached-property/)
- [Cached Property](https://nshipster.com/cached-property/)
- [Cached Property](https://nshipster.com/cached-property/)
- [Cached Property](https://nshipster.com/cached-property/)
- [Cached Property](https://nshipster.com/cached-property/)
- [Cached Property](https://nshipster.com/cached-property/)
- [Cached Property](https://nshipster.com/cached-property/)
- [Cached Property](https://nshipster.com/cached-property/)
- [Cached Property](https://nshipster.com/cached-property/)
- [Cached Property](https://nshipster.com/cached-property/)
- [Cached Property](https://nshipster.com/cached-property/)
- [Cached Property](https://nshipster.com/cached-property/)
- [Cached Property](https://nshipster.com/cached-property/)
- [Cached Property](https://nshipster.com/cached-property/)
- [Cached Property](https://nshipster.com/cached-property/)
- [Cached Property](https://nshipster.com/cached-property/)
- [Cached Property](https://nshipster.com/cached-property/)
- [Cached Property](https://nshipster.com/cached-property/)
- [Cached Property](https://nshipster.com/cached-property/)
- [Cached Property](https://nshipster.com/cached-property/)
- [Cached Property](https://nshipster.com/cached-self._wrappedValue = getter() // cannot assign to property: 'self' is immutableprotocol CachedProperty {
associatedtype Value
init(wrappedValue: @autoclosure @escaping () -> Value, condition: @escaping () -> Bool)
}
@propertyWrapper
struct Cached<Value>: CachedProperty {
private let wrappedValue: @escaping () -> Value
private let condition: @escaping () -> Bool
private var value: Value?
init(wrappedValue: @escaping () -> Value, condition: @escaping () -> Bool) {
self.wrappedValue = wrappedValue
self.condition = condition
}
var wrappedValue: @escaping () -> Value {
get {
return wrappedValue
}
set {
value = nil
}
}
var condition: @escaping () -> Bool {
get {
return condition
}
set {
value = nil
}
}
var value: Value? {
get {
guard let value = value else {
value = wrappedValue()
return value
}
if condition() {
value = wrappedValue()
}
return value
}
set {
value = newValue
}
}
}
extension CachedProperty {
/// Creates a new `CachedProperty` instance that caches the computed value of the given property.
///
/// - Parameters:
/// - wrappedValue: A closure that computes the value of the property.
/// - condition: A closure that returns `true` if the computed value of the property should be recomputed.
/// - Returns: A new `CachedProperty` instance.
static func cached(wrappedValue: @escaping () -> Value, condition: @escaping () -> Bool) -> Cached<Value> {
return Cached(wrappedValue: wrappedValue, condition: condition)
}
}```swift
protocol CachedProperty {
associatedtype Value
init(wrappedValue: @autoclosure @escaping () -> Value, condition: @escaping () -> Bool)
}
// Property wrapper that caches the computed value of a property and recomputes it only when a specified condition changes.
@propertyWrapper
struct Cached<Value>: CachedProperty {
private let wrappedValue: @escaping () -> Value
private let condition: @escaping () -> Bool
private var value: Value?
init(wrappedValue: @escaping () -> Value, condition: @escaping () -> Bool) {
self.wrappedValue = wrappedValue
self.condition = condition
}
var wrappedValue: @escaping () -> Value {
get {
return wrappedValue
}
set {
value = nil
}
}
var condition: @escaping () -> Bool {
get {
return condition
}
set {
value = nil
}
}
var value: Value? {
get {
guard let value = value else {
value = wrappedValue()
return value
}
if condition() {
value = wrappedValue()
}
return value
}
set {
value = newValue
}
}
}
extension CachedProperty {
/// Creates a new `CachedProperty` instance that caches the computed value of the given property.
///
/// - Parameters:
/// - wrappedValue: A closure that computes the value of the property.
/// - condition: A closure that returns `true` if the computed value of the property should be recomputed.
/// - Returns: A new `CachedProperty` instance.
static func cached(wrappedValue: @escaping () -> Value, condition: @escaping () -> Bool) -> Cached<Value> {
return Cached(wrappedValue: wrappedValue, condition: condition)
}
}
```
### 参考
- [Swift 5.5 引入了 Property Wrapper 机制](https://mp.weixin.qq.com/s/Zl2Z9_vhj6wJ9xvjqjQx2w)
- [Swift 5.5 引入了 Property Wrapper 机制](https://mp.weixin.qq.com/s/Zl2Z9_vhj6wJ9xvjqjQx2w)
- [Swift 5.5 引入了 Property Wrapper 机制](https://mp.weixin.qq.com/s/Zl2Z9_vhj6wJ9xvjqjQx2w)
- [Swift 5.5 引入了 Property Wrapper 机制](https://mp.weixin.qq.com/s/Zl2Z9_vhj6wJ9xvjqjQx2w)
- [Swift 5.5 引入了 Property Wrapper 机制](https://mp.weixin.qq.com/s/Zl2Z9_vhj6wJ9xvjqjQx2w)
- [Swift 5.5 引入了 Property Wrapper 机制](https://mp.weixin.qq.com/s/Zl2Z9_vhj6wJ9xvjqjQx2w)
- [Swift 5.5 引入了 Property Wrapper 机制](https://mp.weixin.qq.com/s/Zl2Z9_vhj6wJ9xvjqjQx2w)
- [Swift 5.5 引入了 Property Wrapper 机制](https://mp.weixin.qq.com/s/Zl2Z9_vhj6wJ9xvjqjQx2w)
- [Swift 5.5 引入了 Property Wrapper 机制](https://mp.weixin.qq.com/s/Zl2Z9_vhj6wJ9xvjqjQx2w)
- [Swift 5.5 引入了 Property Wrapper 机制](https://mp.weixin.qq.com/s/Zl2Z9_vhj6wJ9xvjqjQx2w)
- [Swift 5.5 引入了 Property Wrapper 机制](https://mp.weixin.qq.com/s/Zl2Z9_vhj6wJ9xvjqjQx2w)
- [Swiftstruct Cached<Value>: CachedProperty { // property wrapper type 'Cached' has multiple non-static properties named 'wrappedValue'private let wrappedValue: @escaping () -> Value // @escaping attribute may only be used in function parameter positionprivate let condition: @escaping () -> Bool // @escaping attribute may only be used in function parameter positionvar wrappedValue: @escaping () -> Value { // @escaping attribute may only be used in function parameter positionvar condition: @escaping () -> Bool { // @escaping attribute may only be used in function parameter positionvar value: Value? { // invalid redeclaration of 'value'value = wrappedValue() // cannot assign to property: 'self' is immutablevalue = wrappedValue() // cannot assign to value: 'value' is a 'let' constantprotocol CachedProperty {
associatedtype Value
init(wrappedValue: @autoclosure @escaping () -> Value, condition: @escaping () -> Bool)
}
@propertyWrapper
struct Cached<Value>: CachedProperty {
private let wrappedValue: @escaping () -> Value
private let condition: @escaping () -> Bool
private var value: Value?
init(wrappedValue: @escaping () -> Value, condition: @escaping () -> Bool) {
self.wrappedValue = wrappedValue
self.condition = condition
self.value = nil
}
var wrappedValue: @escaping () -> Value {
get {
return self.wrappedValue
}
set {
self.value = newValue
}
}
var condition: @escaping () -> Bool {
get {
return self.condition
}
set {
self.value = nil
}
}
var value: Value? {
get {
guard let value = self.value else {
self.value = self.wrappedValue()
return self.value
}
if self.condition() {
self.value = self.wrappedValue()
}
return value
}
set {
self.value = newValue
}
}
}
extension CachedProperty {
/// Creates a new `CachedProperty` instance that caches the computed value of the given property.
/// - Parameters:
/// - wrappedValue: A closure that computes the value of the property.
/// - condition: A closure that returns `true` if the computed value should be recomputed.
/// - Returns: A new `CachedProperty` instance.
static func cached(wrappedValue: @escaping () -> Value, condition: @escaping () -> Bool) -> Cached<Value> {
return Cached(wrappedValue: wrappedValue, condition: condition)
}
}```swift
protocol CachedProperty {
associatedtype Value
init(wrappedValue: @autoclosure @escaping () -> Value, condition: @escaping () -> Bool)
}
// Property wrapper that caches the computed value of a property and recomputes it only when a specified condition changes.
@propertyWrapper
struct Cached<Value>: CachedProperty {
private let wrappedValue: @escaping () -> Value
private let condition: @escaping () -> Bool
private var value: Value?
init(wrappedValue: @escaping () -> Value, condition: @escaping () -> Bool) {
self.wrappedValue = wrappedValue
self.condition = condition
self.value = nil
}
var wrappedValue: @escaping () -> Value {
get {
return self.wrappedValue
}
set {
self.value = newValue
}
}
var condition: @escaping () -> Bool {
get {
return self.condition
}
set {
self.value = nil
}
}
var value: Value? {
get {
guard let value = self.value else {
self.value = self.wrappedValue()
return self.value
}
if self.condition() {
self.value = self.wrappedValue()
}
return value
}
set {
self.value = newValue
}
}
}
extension CachedProperty {
/// Creates a new `CachedProperty` instance that caches the computed value of the given property.
/// - Parameters:
/// - wrappedValue: A closure that computes the value of the property.
/// - condition: A closure that returns `true` if the computed value should be recomputed.
/// - Returns: A new `CachedProperty` instance.
static func cached(wrappedValue: @escaping () -> Value, condition: @escaping () -> Bool) -> Cached<Value> {
return Cached(wrappedValue: wrappedValue, condition: condition)
}
}
```
### 参考
- [Cached Property](https://www.mobanlab.com/blog/2019/09/11/cached-property/)
- [Swift 中的缓存属性](https://www.jianshu.com/p/429869942c4c)
- [Cached Property](https://www.mobanlab.com/blog/2019/09/11/cached-property/)
- [Swift 中的缓存属性](https://www.jianshu.com/p/429869942c4c)
- [Cached Property](https://www.mobanlab.com/blog/2019/09/11/cached-property/)
- [Swift 中的缓存属性](https://www.jianshu.com/p/429869942c4c)
- [Cached Property](https://www.mobanlab.com/blog/2019/09/11/cached-property/)
- [Swift 中的缓存属性](https://www.jianshu.com/p/429869942c4c)
- [Cached Property](https://www.mobanlab.com/blog/2019/09/11/cached-property/)
- [Swift 中的缓存属性](https://www.jianshu.com/p/429869942c4c)
- [Cached Property](https://www.mobanlab.com/blog/2019/09/11/cached-property/)
- [Swift 中的缓存属性](https://www.jianshu.com/p/429869942c4c)
- [Cached Property](https://www.mobanlab.com/blog/2019/09/11/cached-property/)
- [Swift 中的缓存属性](https://www.jianshu.com/p/429869942c4c)
- [Cached Property](https://www.mobanlab.com/blog/2019/09/11/cached-property/)
- [Swift 中的缓存属性](https://www.jianshu.com/p/429869942c4c)
-struct Cached<Value>: CachedProperty { // property wrapper type 'Cached' has multiple non-static properties named 'wrappedValue'private let wrappedValue: @escaping () -> Value // @escaping attribute may only be used in function parameter positionprivate let condition: @escaping () -> Bool // @escaping attribute may only be used in function parameter positionvar wrappedValue: @escaping () -> Value { // @escaping attribute may only be used in function parameter positionvar condition: @escaping () -> Bool { // @escaping attribute may only be used in function parameter positionvar value: Value? { // invalid redeclaration of 'value'self.value = self.wrappedValue() // cannot assign to property: 'self' is immutableself.value = self.wrappedValue() // cannot assign to property: 'self' is immutableprotocol CachedProperty {
associatedtype Value
init(wrappedValue: @autoclosure @escaping () -> Value, condition: @escaping () -> Bool)
}
@propertyWrapper
struct Cached<Value>: CachedProperty {
private let wrappedValue: @escaping () -> Value
private let condition: @escaping () -> Bool
private var value: Value?
init(wrappedValue: @escaping () -> Value, condition: @escaping () -> Bool) {
self.wrappedValue = wrappedValue
self.condition = condition
}
var wrappedValue: @escaping () -> Value {
get {
return wrappedValue
}
set {
value = nil
}
}
var condition: @escaping () -> Bool {
get {
return condition
}
set {
value = nil
}
}
var value: Value? {
get {
guard let value = value else {
value = wrappedValue()
return value
}
if condition() {
value = wrappedValue()
}
return value
}
set {
value = newValue
}
}
}
extension CachedProperty {
/// Returns a new `Cached` property that caches the computed value of the given property.
///
/// The initial value of the `Cached` property is computed once and stored.
///
/// - Parameters:
/// - wrappedValue: A closure that computes the initial value of the `Cached` property.
/// - condition: A closure that returns `true` when the computed value of the `Cached` property should be recomputed.
@inlinable
static func <Value>(wrappedValue: @escaping () -> Value, condition: @escaping () -> Bool) -> Cached<Value> {
Cached(wrappedValue: wrappedValue, condition: condition)
}
}```swift
protocol CachedProperty {
associatedtype Value
init(wrappedValue: @autoclosure @escaping () -> Value, condition: @escaping () -> Bool)
}
// Property wrapper that caches the computed value of a property and recomputes it only when a specified condition changes.
@propertyWrapper
struct Cached<Value>: CachedProperty {
private let wrappedValue: @escaping () -> Value
private let condition: @escaping () -> Bool
private var value: Value?
init(wrappedValue: @escaping () -> Value, condition: @escaping () -> Bool) {
self.wrappedValue = wrappedValue
self.condition = condition
}
var wrappedValue: @escaping () -> Value {
get {
return wrappedValue
}
set {
value = nil
}
}
var condition: @escaping () -> Bool {
get {
return condition
}
set {
value = nil
}
}
var value: Value? {
get {
guard let value = value else {
value = wrappedValue()
return value
}
if condition() {
value = wrappedValue()
}
return value
}
set {
value = newValue
}
}
}
extension CachedProperty {
/// Returns a new `Cached` property that caches the computed value of the given property.
///
/// The initial value of the `Cached` property is computed once and stored.
///
/// - Parameters:
/// - wrappedValue: A closure that computes the initial value of the `Cached` property.
/// - condition: A closure that returns `true` when the computed value of the `Cached` property should be recomputed.
@inlinable
static func <Value>(wrappedValue: @escaping () -> Value, condition: @escaping () -> Bool) -> Cached<Value> {
Cached(wrappedValue: wrappedValue, condition: condition)
}
}
```
### 参考
- [Cached Property](https://www.swiftbart.com/swift/cached-property/)
- [Cached Property](https://www.objc.io/blog/2020/04/21/cached-property/)
- [Cached Property](https://nshipster.com/cached-property/)
- [Cached Property](https://www.objc.io/issues/23-cocoa-design-patterns/cached-property/)
- [Cached Property](https://www.objc.io/issues/23-cocoa-design-patterns/cached-property/)
- [Cached Property](https://www.objc.io/issues/23-cocoa-design-patterns/cached-property/)
- [Cached Property](https://www.objc.io/issues/23-cocoa-design-patterns/cached-property/)
- [Cached Property](https://www.objc.io/issues/23-cocoa-design-patterns/cached-property/)
- [Cached Property](https://www.objc.io/issues/23-cocoa-design-patterns/cached-property/)
- [Cached Property](https://www.objc.io/issues/23-cocoa-design-patterns/cached-property/)
- [Cached Property](https://www.objc.io/issues/23-cocoa-design-patterns/cached-property/)
- [Cached Property](https://www.objc.io/issues/23-cocoa-design-patterns/cached-property/)
- [Cached Property](https://www.objc.io/issues/23-cocoa-design-patterns/cached-property/)
- [Cached Property](https://www.objc.io/issues/23-cocoa-design-patterns/cached-property/)
- [Cached Property](https://www.objc.io/issues/23-cocoa-design-patterns/cached-property/)
- [Cached Property](https://www.objc.io/issues/23-cocoa-design-patterns/cached-property/)
- [Cached Property](https://www.objc.io/issues/23-cocoa-design-patterns/cached-property/)
- [Cached Property](struct Cached<Value>: CachedProperty { // property wrapper type 'Cached' has multiple non-static properties named 'wrappedValue'private let wrappedValue: @escaping () -> Value // @escaping attribute may only be used in function parameter positionprivate let condition: @escaping () -> Bool // @escaping attribute may only be used in function parameter positionvar wrappedValue: @escaping () -> Value { // @escaping attribute may only be used in function parameter positionvar condition: @escaping () -> Bool { // @escaping attribute may only be used in function parameter positionvar value: Value? { // invalid redeclaration of 'value'value = wrappedValue() // cannot assign to property: 'self' is immutablevalue = wrappedValue() // cannot assign to value: 'value' is a 'let' constantstatic func <Value>(wrappedValue: @escaping () -> Value, condition: @escaping () -> Bool) -> Cached<Value> { // expected '{' in body of function declarationstatic func <Value>(wrappedValue: @escaping () -> Value, condition: @escaping () -> Bool) -> Cached<Value> { // member operator '<()' of protocol 'CachedProperty' must have at least one argument of type 'Self'static func <Value>(wrappedValue: @escaping () -> Value, condition: @escaping () -> Bool) -> Cached<Value> { // expected '(' in argument list of function declarationstatic func <Value>(wrappedValue: @escaping () -> Value, condition: @escaping () -> Bool) -> Cached<Value> { // expected declarationstatic func <Value>(wrappedValue: @escaping () -> Value, condition: @escaping () -> Bool) -> Cached<Value> { // operators must have one or two argumentsstatic func <Value>(wrappedValue: @escaping () -> Value, condition: @escaping () -> Bool) -> Cached<Value> { // consecutive declarations on a line must be separated by ';'protocol CachedProperty {
associatedtype Value
init(wrappedValue: @autoclosure @escaping () -> Value, condition: @escaping () -> Bool)
}
@propertyWrapper
struct Cached<Value>: CachedProperty {
private let wrappedValue: @escaping () -> Value
private let condition: @escaping () -> Bool
private var value: Value?
init(wrappedValue: @escaping () -> Value, condition: @escaping () -> Bool) {
self.wrappedValue = wrappedValue
self.condition = condition
}
var wrappedValue: @escaping () -> Value {
get {
return wrappedValue
}
set {
value = nil
}
}
var condition: @escaping () -> Bool {
get {
return condition
}
set {
value = nil
}
}
var value: Value? {
get {
guard let value = value else {
value = wrappedValue()
return value
}
if condition() {
value = wrappedValue()
}
return value
}
set {
value = newValue
}
}
}
extension CachedProperty {
/// Returns a value that is computed only once and then cached for
/// subsequent accesses.
///
/// - Parameters:
/// - wrappedValue: A closure that computes the value to cache.
/// - condition: A closure that specifies when the value is recomputed.
/// - Returns: A value that is computed only once and then cached for
/// subsequent accesses.
static func `default`(wrappedValue: @escaping () -> Value, condition: @escaping () -> Bool) -> Value {
return Cached(wrappedValue: wrappedValue, condition: condition)
}
}
extension CachedProperty {
/// Returns a value that is computed only once and then cached for
/// subsequent accesses.
///
/// - Parameters:
/// - wrappedValue: A closure that computes the value to cache.
/// - condition: A closure that specifies when the value is recomputed.
/// - Returns: A value that is computed only once and then cached for
/// subsequent accesses.
static func `default`(wrappedValue: @escaping () -> Value) -> Value {
return Cached(wrappedValue: wrappedValue, condition: { true })
}
}```swift
protocol CachedProperty {
associatedtype Value
init(wrappedValue: @autoclosure @escaping () -> Value, condition: @escaping () -> Bool)
}
// Property wrapper that caches the computed value of a property and recomputes it only when a specified condition changes.
@propertyWrapper
struct Cached<Value>: CachedProperty {
private let wrappedValue: @escaping () -> Value
private let condition: @escaping () -> Bool
private var value: Value?
init(wrappedValue: @escaping () -> Value, condition: @escaping () -> Bool) {
self.wrappedValue = wrappedValue
self.condition = condition
}
var wrappedValue: @escaping () -> Value {
get {
return wrappedValue
}
set {
value = nil
}
}
var condition: @escaping () -> Bool {
get {
return condition
}
set {
value = nil
}
}
var value: Value? {
get {
guard let value = value else {
value = wrappedValue()
return value
}
if condition() {
value = wrappedValue()
}
return value
}
set {
value = newValue
}
}
}
extension CachedProperty {
/// Returns a value that is computed only once and then cached for
/// subsequent accesses.
///
/// - Parameters:
/// - wrappedValue: A closure that computes the value to cache.
/// - condition: A closure that specifies when the value is recomputed.
/// - Returns: A value that is computed only once and then cached for
/// subsequent accesses.
static func `default`(wrappedValue: @escaping () -> Value, condition: @escaping () -> Bool) -> Value {
return Cached(wrappedValue: wrappedValue, condition: condition)
}
}
extension CachedProperty {
/// Returns a value that is computed only once and then cached for
/// subsequent accesses.
///
/// - Parameters:
/// - wrappedValue: A closure that computes the value to cache.
/// - condition: A closure that specifies when the value is recomputed.
/// - Returns: A value that is computed only once and then cached for
/// subsequent accesses.
static func `default`(wrappedValue: @escaping () -> Value) -> Value {
return Cached(wrappedValue: wrappedValue, condition: { true })
}
}
```
### 参考
- [Swift 5.3 引入的新特性](https://mp.weixin.qq.com/s/qdYmrYjq_3UJyZ82LhMq8A)
- [Swift 5.3 引入的新特性](https://mp.weixin.qq.com/s/qdYmrYjq_3UJyZ82LhMq8A)
- [Swift 5.3 引入的新特性](https://mp.weixin.qq.com/s/qdYmrYjq_3UJyZ82LhMq8A)
- [Swift 5.3 引入的新特性](https://mp.weixin.qq.com/s/qdYmrYjq_3UJyZ82LhMq8A)
- [Swift 5.3 引入的新特性](https://mp.weixin.qq.com/s/qdYmrYjq_3UJyZ82LhMq8A)
- [Swift 5.3 引入的新特性](https://mp.weixin.qq.com/s/qdYmrYjq_3UJyZ82LhMq8A)
- [Swift 5.3 引入的新特性](https://mp.weixin.qq.com/s/qdYmrYjq_3UJyZ82LhMq8A)
- [Swift 5.3 引入的新特性](https://mp.weixin.qq.com/s/qdYmrYjq_3UJyZ82LhMq8A)
- [Swift 5.3 引入的新特性](https://mp.weixin.qq.com/s/qdYmrYjq_3UJyZ82LhMq8Astruct Cached<Value>: CachedProperty { // property wrapper type 'Cached' has multiple non-static properties named 'wrappedValue'private let wrappedValue: @escaping () -> Value // @escaping attribute may only be used in function parameter positionprivate let condition: @escaping () -> Bool // @escaping attribute may only be used in function parameter positionvar wrappedValue: @escaping () -> Value { // @escaping attribute may only be used in function parameter positionvar condition: @escaping () -> Bool { // @escaping attribute may only be used in function parameter positionvar value: Value? { // invalid redeclaration of 'value'value = wrappedValue() // cannot assign to property: 'self' is immutablevalue = wrappedValue() // cannot assign to value: 'value' is a 'let' constantreturn Cached(wrappedValue: wrappedValue, condition: condition) // cannot convert return expression of type 'Cached<Self.Value>' to return type 'Self.Value'return Cached(wrappedValue: wrappedValue, condition: { true }) // cannot convert return expression of type 'Cached<Self.Value>' to return type 'Self.Value'protocol CachedProperty {
associatedtype Value
init(wrappedValue: @autoclosure @escaping () -> Value, condition: @escaping () -> Bool)
}
@propertyWrapper
struct Cached<Value>: CachedProperty {
private let wrappedValue: @escaping () -> Value
private let condition: @escaping () -> Bool
private var value: Value?
private let lock = Lock()
init(wrappedValue: @escaping () -> Value, condition: @escaping () -> Bool) {
self.wrappedValue = wrappedValue
self.condition = condition
}
var wrappedValue: @escaping () -> Value {
get {
return self.wrappedValue
}
set {
self.value = nil
}
}
var condition: @escaping () -> Bool {
get {
return self.condition
}
set {
self.value = nil
}
}
var value: Value? {
get {
guard let value = self.value else {
self.lock.lock()
guard let value = self.value else {
self.value = self.wrappedValue()
self.lock.unlock()
return self.value
}
}
return value
}
set {
self.value = newValue
}
}
}```swift
protocol CachedProperty {
associatedtype Value
init(wrappedValue: @autoclosure @escaping () -> Value, condition: @escaping () -> Bool)
}
// Property wrapper that caches the computed value of a property and recomputes it only when a specified condition changes.
@propertyWrapper
struct Cached<Value>: CachedProperty {
private let wrappedValue: @escaping () -> Value
private let condition: @escaping () -> Bool
private var value: Value?
private let lock = Lock()
init(wrappedValue: @escaping () -> Value, condition: @escaping () -> Bool) {
self.wrappedValue = wrappedValue
self.condition = condition
}
var wrappedValue: @escaping () -> Value {
get {
return self.wrappedValue
}
set {
self.value = nil
}
}
var condition: @escaping () -> Bool {
get {
return self.condition
}
set {
self.value = nil
}
}
var value: Value? {
get {
guard let value = self.value else {
self.lock.lock()
guard let value = self.value else {
self.value = self.wrappedValue()
self.lock.unlock()
return self.value
}
}
return value
}
set {
self.value = newValue
}
}
}
```
### 参考
- [Cached Property](https://www.bartlettsmith.com/blog/cached-property-swift-property-wrapper/)
- [Cached Property](https://www.bartlettsmith.com/blog/cached-property-swift-property-wrapper/)
- [Cached Property](https://www.bartlettsmith.com/blog/cached-property-swift-property-wrapper/)
- [Cached Property](https://www.bartlettsmith.com/blog/cached-property-swift-property-wrapper/)
- [Cached Property](https://www.bartlettsmith.com/blog/cached-property-swift-property-wrapper/)
- [Cached Property](https://www.bartlettsmith.com/blog/cached-property-swift-property-wrapper/)
- [Cached Property](https://www.bartlettsmith.com/blog/cached-property-swift-property-wrapper/)
- [Cached Property](https://www.bartlettsmith.com/blog/cached-property-swift-property-wrapper/)
- [Cached Property](https://www.bartlettsmith.com/blog/cached-property-swift-property-wrapper/)
- [Cached Property](https://www.bartlettsmith.com/blog/cached-property-swift-property-wrapper/)
- [Cached Property](https://www.bartlettsmith.com/blog/cached-property-swift-property-wrapper/)
- [Cached Property](https://www.bartlettsmith.com/blog/cached-property-swift-property-wrapper/)
- [Cached Property](https://www.bartlettsmith.com/blog/cached-property-swift-property-wrapper/)
- [Cached Property](https://www.bartlettsmith.com/blog/cached-property-swift-property-wrapper/)
- [Cached Property](https://www.bartlettsmith.com/blog/cached-property-swift-property-wrapper/)
- [Cached Property](https://www.bartlettsmith.com/blog/cached-property-swift-property-wrapper/)
- [Cached Property](https://www.bartlettsmith.com/blog/cached-property-swift-property-wrapper/)
- [Cached Property](https://www.bartlettsmith.com/blog/cached-property-swift-property-wrapper/)
- [Cached Property](https://www.bartlettsmith.com/blog/cached-property-swift-property-wrapper/)
- [Cached Property](https://www.bartlettsmith.com/blog/cached-property-swift-property-wrapper/)
- [Cached Property](https://www.bartlettsmith.com/blog/cached-property-swift-property-wrapper/)
- [Cached Property](https://www.bartlettsmith.com/blog/cached-property-swiftstruct Cached<Value>: CachedProperty { // property wrapper type 'Cached' has multiple non-static properties named 'wrappedValue'private let wrappedValue: @escaping () -> Value // @escaping attribute may only be used in function parameter positionprivate let condition: @escaping () -> Bool // @escaping attribute may only be used in function parameter positionprivate let lock = Lock() // cannot find 'Lock' in scopevar wrappedValue: @escaping () -> Value { // @escaping attribute may only be used in function parameter positionvar condition: @escaping () -> Bool { // @escaping attribute may only be used in function parameter positionvar value: Value? { // invalid redeclaration of 'value'self.value = self.wrappedValue() // cannot assign to property: 'self' is immutableprotocol CachedProperty {
associatedtype Value
init(wrappedValue: @autoclosure @escaping () -> Value, condition: @escaping () -> Bool)
}
@propertyWrapper
struct Cached<Value>: CachedProperty {
private let wrappedValue: @escaping () -> Value
private let condition: @escaping () -> Bool
private var value: Value?
private let lock = Lock()
init(wrappedValue: @escaping () -> Value, condition: @escaping () -> Bool) {
self.wrappedValue = wrappedValue
self.condition = condition
}
var wrappedValue: @escaping () -> Value {
get {
guard let value = value else {
let result = wrappedValue()
value = result
return result
}
return value
}
set {
value = newValue
}
}
var condition: @escaping () -> Bool {
get {
return condition()
}
set {
condition = newValue
}
}
}```swift
protocol CachedProperty {
associatedtype Value
init(wrappedValue: @autoclosure @escaping () -> Value, condition: @escaping () -> Bool)
}
// Property wrapper that caches the computed value of a property and recomputes it only when a specified condition changes.
@propertyWrapper
struct Cached<Value>: CachedProperty {
private let wrappedValue: @escaping () -> Value
private let condition: @escaping () -> Bool
private var value: Value?
private let lock = Lock()
init(wrappedValue: @escaping () -> Value, condition: @escaping () -> Bool) {
self.wrappedValue = wrappedValue
self.condition = condition
}
var wrappedValue: @escaping () -> Value {
get {
guard let value = value else {
let result = wrappedValue()
value = result
return result
}
return value
}
set {
value = newValue
}
}
var condition: @escaping () -> Bool {
get {
return condition()
}
set {
condition = newValue
}
}
}
```
### 参考
- [Cached Property](https://nshipster.com/cached-property/)
- [Swift 4 的新特性：属性包装器 Property Wrapper](https://www.jianshu.com/p/18567787790a)
- [Swift 4 Property Wrapper](https://www.jianshu.com/p/67065040925b)
- [Swift 4 Property Wrapper](https://www.jianshu.com/p/67065040925b)
- [Swift 4 Property Wrapper](https://www.jianshu.com/p/67065040925b)
- [Swift 4 Property Wrapper](https://www.jianshu.com/p/67065040925b)
- [Swift 4 Property Wrapper](https://www.jianshu.com/p/67065040925b)
- [Swift 4 Property Wrapper](https://www.jianshu.com/p/67065040925b)
- [Swift 4 Property Wrapper](https://www.jianshu.com/p/67065040925b)
- [Swift 4 Property Wrapper](https://www.jianshu.com/p/67065040925b)
- [Swift 4 Property Wrapper](https://www.jianshu.com/p/67065040925b)
- [Swift 4 Property Wrapper](https://www.jianshu.com/p/67065040925b)
- [Swift 4 Property Wrapper](https://www.jianshu.com/p/67065040925b)
- [Swift 4 Property Wrapper](https://www.jianshu.com/p/67065040925b)
- [Swift 4 Property Wrapper](https://www.jianshu.com/p/67065040925b)
- [Swift 4 Property Wrapper](https://www.jianshu.com/p/67065040925b)
- [Swift 4 Property Wrapper](https://www.jianshu.com/p/67065040925b)
- [Swift 4 Property Wrapper](https://www.jianshu.com/p/67065040925b)
- [Swift 4 Property Wrapper](https://www.jianshu.com/p/67065040925b)
- [Swift 4 Property Wrapper](https://www.jianshu.com/p/67065040925b)
- [Swift 4 Property Wrapper](https://www.jianshu.com/p/67065040925b)
- [Swift 4 Property Wrapper](https://www.jianshu.com/p/67065040925b)
- [Swift 4 Property Wrapper](https://www.jianshu.com/p/struct Cached<Value>: CachedProperty { // property wrapper type 'Cached' has multiple non-static properties named 'wrappedValue'private let wrappedValue: @escaping () -> Value // @escaping attribute may only be used in function parameter positionprivate let condition: @escaping () -> Bool // @escaping attribute may only be used in function parameter positionprivate let lock = Lock() // cannot find 'Lock' in scopevar wrappedValue: @escaping () -> Value { // @escaping attribute may only be used in function parameter positionvalue = result // cannot assign to property: 'self' is immutablevar condition: @escaping () -> Bool { // @escaping attribute may only be used in function parameter positionprotocol CachedProperty {
associatedtype Value
init(wrappedValue: @autoclosure @escaping () -> Value, condition: @escaping () -> Bool)
}
@propertyWrapper
struct Cached<Value>: CachedProperty {
private let wrappedValue: @escaping () -> Value
private let condition: @escaping () -> Bool
private var value: Value?
init(wrappedValue: @escaping () -> Value, condition: @escaping () -> Bool) {
self.wrappedValue = wrappedValue
self.condition = condition
}
var wrappedValue: @escaping () -> Value {
get {
return wrappedValue
}
set {
value = nil
}
}
var condition: @escaping () -> Bool {
get {
return condition
}
set {
value = nil
}
}
var value: Value? {
get {
guard let value = value else {
value = wrappedValue()
return value
}
guard condition() else {
return value
}
value = wrappedValue()
return value
}
set {
value = newValue
}
}
}
extension CachedProperty {
/// Creates a new `Cached` property wrapper with the given `wrappedValue` and `condition`.
///
/// The initializer is used as the initializer for the property wrapper.
///
/// - Parameters:
/// - wrappedValue: The closure that computes the value of the property.
/// - condition: The closure that determines whether the property should be recomputed.
@inlinable
public init<WrappedValue: @escaping () -> Value>(
wrappedValue: @escaping () -> WrappedValue,
condition: @escaping () -> Bool
) where WrappedValue == Value {
self.init(wrappedValue: wrappedValue, condition: condition)
}
}
extension CachedProperty {
/// Creates a new `Cached` property wrapper with the given `wrappedValue` and `condition`.
///
/// The initializer is used as the initializer for the property wrapper.
///
/// - Parameters:
/// - wrappedValue: The closure that computes the value of the property.
/// - condition: The closure that determines whether the property should be recomputed.
@inlinable
public init<WrappedValue: @escaping () -> Value,
WrappedValue2: @escaping () -> WrappedValue,
Condition: @escaping () -> Bool>(
wrappedValue: @escaping () -> WrappedValue,
condition: @escaping () -> Condition
) where WrappedValue == Value, WrappedValue2 == Value {
self.init(wrappedValue: wrappedValue, condition: condition)
}
}```swift
protocol CachedProperty {
associatedtype Value
init(wrappedValue: @autoclosure @escaping () -> Value, condition: @escaping () -> Bool)
}
// Property wrapper that caches the computed value of a property and recomputes it only when a specified condition changes.
@propertyWrapper
struct Cached<Value>: CachedProperty {
private let wrappedValue: @escaping () -> Value
private let condition: @escaping () -> Bool
private var value: Value?
init(wrappedValue: @escaping () -> Value, condition: @escaping () -> Bool) {
self.wrappedValue = wrappedValue
self.condition = condition
}
var wrappedValue: @escaping () -> Value {
get {
return wrappedValue
}
set {
value = nil
}
}
var condition: @escaping () -> Bool {
get {
return condition
}
set {
value = nil
}
}
var value: Value? {
get {
guard let value = value else {
value = wrappedValue()
return value
}
guard condition() else {
return value
}
value = wrappedValue()
return value
}
set {
value = newValue
}
}
}
extension CachedProperty {
/// Creates a new `Cached` property wrapper with the given `wrappedValue` and `condition`.
///
/// The initializer is used as the initializer for the property wrapper.
///
/// - Parameters:
/// - wrappedValue: The closure that computes the value of the property.
/// - condition: The closure that determines whether the property should be recomputed.
@inlinable
public init<WrappedValue: @escaping () -> Value>(
wrappedValue: @escaping () -> WrappedValue,
condition: @escaping () -> Bool
) where WrappedValue == Value {
self.init(wrappedValue: wrappedValue, condition: condition)
}
}
extension CachedProperty {
/// Creates a new `Cached` property wrapper with the given `wrappedValue` and `condition`.
///
/// The initializer is used as the initializer for the property wrapper.
///
/// - Parameters:
/// - wrappedValue: The closure that computes the value of the property.
/// - condition: The closure that determines whether the property should be recomputed.
@inlinable
public init<WrappedValue: @escaping () -> Value,
WrappedValue2: @escaping () -> WrappedValue,
Condition: @escaping () -> Bool>(
wrappedValue: @escaping () -> WrappedValue,
condition: @escaping () -> Condition
) where WrappedValue == Value, WrappedValue2 == Value {
self.init(wrappedValue: wrappedValue, condition: condition)
}
}
```
### 参考
- [Swift 4.2 引入的新特性](https://www.jianshu.com/p/130187194701)
- [Swift 4.2 引入的新特性](https://www.jianshu.com/p/130187194701)
- [Swift 4.2 引入的新特性](https://www.jianshu.com/p/130187194701)
- [Swift 4.2 引入的新特性](https://www.jianshu.com/p/130187194701)
- [Swift 4.2 引入的新特性](https://www.jianshu.com/p/130187194701)
- [Swift 4.2 引入的新特性](https://www.jianshu.com/p/130187194701)
- [Swift 4.2 引入的新特性](https://www.jianshu.com/p/130187194701)
- [Swift 4.2 引入的新特性](https://www.jianshu.com/p/130187194701)
- [Swift 4.2 引入的新特性](https://www.jianshu.com/p/13018719struct Cached<Value>: CachedProperty { // property wrapper type 'Cached' has multiple non-static properties named 'wrappedValue'private let wrappedValue: @escaping () -> Value // @escaping attribute may only be used in function parameter positionprivate let condition: @escaping () -> Bool // @escaping attribute may only be used in function parameter positionvar wrappedValue: @escaping () -> Value { // @escaping attribute may only be used in function parameter positionvar condition: @escaping () -> Bool { // @escaping attribute may only be used in function parameter positionvar value: Value? { // invalid redeclaration of 'value'value = wrappedValue() // cannot assign to property: 'self' is immutablevalue = wrappedValue() // cannot assign to value: 'value' is a 'let' constantpublic init<WrappedValue: @escaping () -> Value>( // expected a class type or protocol-constrained type restricting 'WrappedValue'public init<WrappedValue: @escaping () -> Value, // expected a class type or protocol-constrained type restricting 'WrappedValue'condition: @escaping () -> Condition // cannot find type 'Condition' in scope) where WrappedValue == Value, WrappedValue2 == Value { // cannot find type 'WrappedValue2' in scopeself.init(wrappedValue: wrappedValue, condition: condition) // generic parameter 'WrappedValue' could not be inferredinfix operator >>>: FunctionCompositionPrecedence
precedencegroup FunctionCompositionPrecedence {
associativity: left
precedence: 100
}
func >>> <A, B, C> (f: A -> B, g: B -> C) -> A -> C {
return { x in f(g(x)) }
}
class Solution {
func reverse(_ x: Int) -> Int {
var x = x
var res = 0
while x != 0 {
res = res * 10 + x % 10
x /= 10
}
return res
}
}```swift
infix operator >>>: FunctionCompositionPrecedence
// Custom infix operator >>> that composes two functions. The operator should take two functions and return a new function that represents the composition of the two functions (i.e., the output of the first function becomes the input of the second function).
precedencegroup FunctionCompositionPrecedence {
associativity: left
precedence: 100
}
func >>> <A, B, C> (f: A -> B, g: B -> C) -> A -> C {
return { x in f(g(x)) }
}
```
### 代码
```swift
class Solution {
func reverse(_ x: Int) -> Int {
var x = x
var res = 0
while x != 0 {
res = res * 10 + x % 10
x /= 10
}
return res
}
}
```precedence: 100 // 'precedence' is not a valid precedence group attributefunc >>> <A, B, C> (f: A -> B, g: B -> C) -> A -> C { // single argument function types require parenthesesfunc >>> <A, B, C> (f: A -> B, g: B -> C) -> A -> C { // single argument function types require parenthesesfunc >>> <A, B, C> (f: A -> B, g: B -> C) -> A -> C { // single argument function types require parenthesesreturn { x in f(g(x)) } // cannot convert value of type 'B' to closure result type 'C'return { x in f(g(x)) } // cannot convert value of type 'C' to expected argument type 'A'return { x in f(g(x)) } // cannot convert value of type 'A' to expected argument type 'B'infix operator >>>: FunctionCompositionPrecedence
precedencegroup FunctionCompositionPrecedence {
associativity: left
precedence: 1000
}
func >>> <A, B, C> (f: A -> B, g: B -> C) -> A -> C {
return { x in f(g(x)) }
}
class Solution {
func reverse(_ x: Int) -> Int {
var x = x
var res = 0
while x != 0 {
res = res * 10 + x % 10
x /= 10
}
return res
}
}```swift
infix operator >>>: FunctionCompositionPrecedence
// Custom infix operator >>> that composes two functions. The operator should take two functions and return a new function that represents the composition of the two functions (i.e., the output of the first function becomes the input of the second function).
precedencegroup FunctionCompositionPrecedence {
associativity: left
precedence: 1000
}
func >>> <A, B, C> (f: A -> B, g: B -> C) -> A -> C {
return { x in f(g(x)) }
}
```
### 代码
```swift
class Solution {
func reverse(_ x: Int) -> Int {
var x = x
var res = 0
while x != 0 {
res = res * 10 + x % 10
x /= 10
}
return res
}
}
```precedence: 1000 // 'precedence' is not a valid precedence group attributefunc >>> <A, B, C> (f: A -> B, g: B -> C) -> A -> C { // single argument function types require parenthesesfunc >>> <A, B, C> (f: A -> B, g: B -> C) -> A -> C { // single argument function types require parenthesesfunc >>> <A, B, C> (f: A -> B, g: B -> C) -> A -> C { // single argument function types require parenthesesreturn { x in f(g(x)) } // cannot convert value of type 'B' to closure result type 'C'return { x in f(g(x)) } // cannot convert value of type 'C' to expected argument type 'A'return { x in f(g(x)) } // cannot convert value of type 'A' to expected argument type 'B'infix operator >>>: FunctionCompositionPrecedence
precedencegroup FunctionCompositionPrecedence {
associativity: left
assignment: left
right: ">>>"
}
func >>> <A, B, C> (f: A -> B, g: B -> C) -> A -> C {
return { x in f(g(x)) }
}
class Solution {
func reverse(_ x: Int) -> Int {
var x = x
var result = 0
while x != 0 {
result = result * 10 + x % 10
x /= 10
}
return result
}
}```swift
infix operator >>>: FunctionCompositionPrecedence
// Custom infix operator >>> that composes two functions. The operator should take two functions and return a new function that represents the composition of the two functions (i.e., the output of the first function becomes the input of the second function).
precedencegroup FunctionCompositionPrecedence {
associativity: left
assignment: left
right: ">>>"
}
func >>> <A, B, C> (f: A -> B, g: B -> C) -> A -> C {
return { x in f(g(x)) }
}
```
### 代码
```swift
class Solution {
func reverse(_ x: Int) -> Int {
var x = x
var result = 0
while x != 0 {
result = result * 10 + x % 10
x /= 10
}
return result
}
}
```assignment: left // expected 'true' or 'false' after 'assignment'func >>> <A, B, C> (f: A -> B, g: B -> C) -> A -> C { // single argument function types require parenthesesfunc >>> <A, B, C> (f: A -> B, g: B -> C) -> A -> C { // single argument function types require parenthesesfunc >>> <A, B, C> (f: A -> B, g: B -> C) -> A -> C { // single argument function types require parenthesesreturn { x in f(g(x)) } // cannot convert value of type 'A' to expected argument type 'B'return { x in f(g(x)) } // cannot convert value of type 'B' to closure result type 'C'return { x in f(g(x)) } // cannot convert value of type 'C' to expected argument type 'A'infix operator >>>: FunctionCompositionPrecedence
precedencegroup FunctionCompositionPrecedence {
associativity: left
precedence: 100
}
func >>> <A, B, C> (f: A -> B, g: B -> C) -> A -> C {
return { x in f(g(x)) }
}
class Solution {
func reverse(_ x: Int) -> Int {
var x = x
var result = 0
while x != 0 {
result = result * 10 + x % 10
x /= 10
}
return result
}
}```swift
infix operator >>>: FunctionCompositionPrecedence
// Custom infix operator >>> that composes two functions. The operator should take two functions and return a new function that represents the composition of the two functions (i.e., the output of the first function becomes the input of the second function).
precedencegroup FunctionCompositionPrecedence {
associativity: left
precedence: 100
}
func >>> <A, B, C> (f: A -> B, g: B -> C) -> A -> C {
return { x in f(g(x)) }
}
```
### 代码
```swift
class Solution {
func reverse(_ x: Int) -> Int {
var x = x
var result = 0
while x != 0 {
result = result * 10 + x % 10
x /= 10
}
return result
}
}
```precedence: 100 // 'precedence' is not a valid precedence group attributefunc >>> <A, B, C> (f: A -> B, g: B -> C) -> A -> C { // single argument function types require parenthesesfunc >>> <A, B, C> (f: A -> B, g: B -> C) -> A -> C { // single argument function types require parenthesesfunc >>> <A, B, C> (f: A -> B, g: B -> C) -> A -> C { // single argument function types require parenthesesreturn { x in f(g(x)) } // cannot convert value of type 'B' to closure result type 'C'return { x in f(g(x)) } // cannot convert value of type 'C' to expected argument type 'A'return { x in f(g(x)) } // cannot convert value of type 'A' to expected argument type 'B'infix operator >>>: FunctionCompositionPrecedence
precedencegroup FunctionCompositionPrecedence {
associativity: left
assignment: left
right: ">>>"
}
func >>> <A, B, C> (f: A -> B, g: B -> C) -> A -> C {
return { x in f(g(x)) }
}
func compose<A, B, C>(f: A -> B, g: B -> C) -> A -> C {
return { x in g(f(x)) }
}
func composeWith<A, B, C>(f: A -> B, g: B -> C) -> A -> C {
return { x in g(f(x)) }
}
func curry<A, B, C>(f: A -> B -> C) -> A -> B -> C {
return { a in { b in f(a)(b) } }
}
public struct Function<A, B> {
typealias FunctionType = A -> B
let fn: FunctionType
public init(_ fn: FunctionType) {
self.fn = fn
}
}
public struct Function1<A> {
typealias FunctionType = A -> A
let fn: FunctionType
public init(_ fn: FunctionType) {
self.fn = fn
}
}
public struct Closure<A, B> {
typealias FunctionType = A -> B
let fn: FunctionType
public init(_ fn: FunctionType) {
self.fn = fn
}
}```swift
infix operator >>>: FunctionCompositionPrecedence
// Custom infix operator >>> that composes two functions. The operator should take two functions and return a new function that represents the composition of the two functions (i.e., the output of the first function becomes the input of the second function).
precedencegroup FunctionCompositionPrecedence {
associativity: left
assignment: left
right: ">>>"
}
func >>> <A, B, C> (f: A -> B, g: B -> C) -> A -> C {
return { x in f(g(x)) }
}
```
### 2.2.2. 函数组合
函数组合是函数式编程中的一个重要概念，它允许我们将多个函数组合在一起，以实现复杂的操作。在Swift中，我们可以使用`Compose`和`ComposeWith`函数来实现函数组合。
```swift
func compose<A, B, C>(f: A -> B, g: B -> C) -> A -> C {
return { x in g(f(x)) }
}
func composeWith<A, B, C>(f: A -> B, g: B -> C) -> A -> C {
return { x in g(f(x)) }
}
```
### 2.2.3. 函数柯里化
函数柯里化是一种将多个参数合并为一个参数的技巧。在Swift中，我们可以使用`curry`函数来实现函数柯里化。
```swift
func curry<A, B, C>(f: A -> B -> C) -> A -> B -> C {
return { a in { b in f(a)(b) } }
}
```
### 2.2.4. 函数式编程中的高阶函数
高阶函数是函数式编程中的一个重要概念，它允许我们将函数作为参数传递给另一个函数，或者将函数作为返回值。在Swift中，我们可以使用`Function`和`Function1`类型来实现高阶函数。
```swift
public struct Function<A, B> {
typealias FunctionType = A -> B
let fn: FunctionType
public init(_ fn: FunctionType) {
self.fn = fn
}
}
public struct Function1<A> {
typealias FunctionType = A -> A
let fn: FunctionType
public init(_ fn: FunctionType) {
self.fn = fn
}
}
```
### 2.2.5. 函数式编程中的闭包
闭包是一种将函数作为变量传递给另一个函数的技巧。在Swift中，我们可以使用`Closure`类型来实现闭包。
```swift
public struct Closure<A, B> {
typealias FunctionType = A -> B
let fn: FunctionType
public init(_ fn: FunctionType) {
self.fn = fn
}
}
```
### 2.2.6. 函数式编程中的高阶函数和闭包
高阶函数和闭包是函数式编程中的重要概念，它们允许我们将函数作为参数传递给另一个函数，或者将函数作为返回值。在Swift中，我们可以使用`Function`和`Closure`类型来实现高阶函数和闭包。
```swift
public struct Function<A, B> {
typealias FunctionType = A -> B
let fn: FunctionType
public init(_ fn: FunctionType) {
self.fn = fn
}
}
public struct Closure<A, B> {
typealias FunctionType = A -> B
let fn: FunctionType
public init(_ fn: FunctionType) {
self.fn = fn
}
}
```
## 2.3. 函数式编程中的高阶函数和闭包
高阶函数和闭包是函数式编程中的重要概念，它们允许我们将函数作为参数传递给另一个函数，或者将函数作为返回值。在Swift中，我们可以使用`Function`和`Closure`类型来实现高阶函数和闭包。
```swift
public struct Function<A, B> {
typealias FunctionType = A -> B
let fn: FunctionType
public init(_ fn: FunctionType) {
self.fn = fn
}
}
public struct Closure<A, B> {
typealias FunctionType = A -> B
let fn: FunctionType
public init(_ fn: FunctionType) {
self.fn = fn
}
}
```
## 2.4. 函数式编程中的高阶函数和闭包assignment: left // expected 'true' or 'false' after 'assignment'func >>> <A, B, C> (f: A -> B, g: B -> C) -> A -> C { // single argument function types require parenthesesfunc >>> <A, B, C> (f: A -> B, g: B -> C) -> A -> C { // single argument function types require parenthesesfunc >>> <A, B, C> (f: A -> B, g: B -> C) -> A -> C { // single argument function types require parenthesesreturn { x in f(g(x)) } // cannot convert value of type 'C' to expected argument type 'A'return { x in f(g(x)) } // cannot convert value of type 'A' to expected argument type 'B'return { x in f(g(x)) } // cannot convert value of type 'B' to closure result type 'C'func compose<A, B, C>(f: A -> B, g: B -> C) -> A -> C { // single argument function types require parenthesesfunc compose<A, B, C>(f: A -> B, g: B -> C) -> A -> C { // single argument function types require parenthesesfunc compose<A, B, C>(f: A -> B, g: B -> C) -> A -> C { // single argument function types require parenthesesfunc composeWith<A, B, C>(f: A -> B, g: B -> C) -> A -> C { // single argument function types require parenthesesfunc composeWith<A, B, C>(f: A -> B, g: B -> C) -> A -> C { // single argument function types require parenthesesfunc composeWith<A, B, C>(f: A -> B, g: B -> C) -> A -> C { // single argument function types require parenthesesfunc curry<A, B, C>(f: A -> B -> C) -> A -> B -> C { // single argument function types require parenthesesfunc curry<A, B, C>(f: A -> B -> C) -> A -> B -> C { // single argument function types require parenthesesfunc curry<A, B, C>(f: A -> B -> C) -> A -> B -> C { // single argument function types require parenthesesfunc curry<A, B, C>(f: A -> B -> C) -> A -> B -> C { // single argument function types require parenthesestypealias FunctionType = A -> B // single argument function types require parenthesespublic init(_ fn: FunctionType) { // initializer cannot be declared public because its parameter uses an internal typeself.fn = fn // assigning non-escaping parameter 'fn' to an @escaping closuretypealias FunctionType = A -> A // single argument function types require parenthesespublic init(_ fn: FunctionType) { // initializer cannot be declared public because its parameter uses an internal typeself.fn = fn // assigning non-escaping parameter 'fn' to an @escaping closuretypealias FunctionType = A -> B // single argument function types require parenthesespublic init(_ fn: FunctionType) { // initializer cannot be declared public because its parameter uses an internal typeself.fn = fn // assigning non-escaping parameter 'fn' to an @escaping closureinfix operator >>>: FunctionCompositionPrecedence
precedencegroup FunctionCompositionPrecedence {
associativity: left
precedence: 1000
}
func >>> <A, B, C>(f: A -> B, g: B -> C) -> A -> C {
return { a in f(a)(g(a)) }
}
class Solution {
func reverse(_ x: Int) -> Int {
var x = x
var res = 0
while x != 0 {
res = res * 10 + x % 10
x /= 10
}
return res
}
}```swift
infix operator >>>: FunctionCompositionPrecedence
// Custom infix operator >>> that composes two functions. The operator should take two functions and return a new function that represents the composition of the two functions (i.e., the output of the first function becomes the input of the second function).
precedencegroup FunctionCompositionPrecedence {
associativity: left
precedence: 1000
}
func >>> <A, B, C>(f: A -> B, g: B -> C) -> A -> C {
return { a in f(a)(g(a)) }
}
```
### 代码
```swift
class Solution {
func reverse(_ x: Int) -> Int {
var x = x
var res = 0
while x != 0 {
res = res * 10 + x % 10
x /= 10
}
return res
}
}
```precedence: 1000 // 'precedence' is not a valid precedence group attributefunc >>> <A, B, C>(f: A -> B, g: B -> C) -> A -> C { // single argument function types require parenthesesfunc >>> <A, B, C>(f: A -> B, g: B -> C) -> A -> C { // single argument function types require parenthesesfunc >>> <A, B, C>(f: A -> B, g: B -> C) -> A -> C { // single argument function types require parenthesesreturn { a in f(a)(g(a)) } // cannot convert value of type 'A' to expected argument type 'B'return { a in f(a)(g(a)) } // cannot call value of non-function type 'B'infix operator >>>: FunctionCompositionPrecedence
precedencegroup FunctionCompositionPrecedence {
associativity: left
assignment: left
right: ">>>"
}
public func >>> <A, B, C>(f: A -> B, g: B -> C) -> A -> C {
return { x in f(x)(g(x)) }
}
func compose<A, B, C>(f: A -> B, g: B -> C) -> A -> C {
return f >>> g
}
func compose<A, B, C, D>(f: A -> B, g: B -> C, h: C -> D) -> A -> D {
return f >>> g >>> h
}
func compose<A, B, C, D, E>(f: A -> B, g: B -> C, h: C -> D, i: D -> E) -> A -> E {
return f >>> g >>> h >>> i
}
func compose<A, B, C, D, E, F>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F) -> A -> F {
return f >>> g >>> h >>> i >>> j
}
func compose<A, B, C, D, E, F, G>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G) -> A -> G {
return f >>> g >>> h >>> i >>> j >>> k
}
func compose<A, B, C, D, E, F, G, H>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H) -> A -> H {
return f >>> g >>> h >>> i >>> j >>> k >>> l
}
func compose<A, B, C, D, E, F, G, H, I>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H, m: H -> I) -> A -> I {
return f >>> g >>> h >>> i >>> j >>> k >>> l >>> m
}
func compose<A, B, C, D, E, F, G, H, I, J>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H, m: H -> I, n: I -> J) -> A -> J {
return f >>> g >>> h >>> i >>> j >>> k >>> l >>> m >>> n
}
func compose<A, B, C, D, E, F, G, H, I, J, K>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H, m: H -> I, n: I -> J, o: J -> K) -> A -> K {
return f >>> g >>> h >>> i >>> j >>> k >>> l >>> m >>> n >>> o
}```swift
infix operator >>>: FunctionCompositionPrecedence
// Custom infix operator >>> that composes two functions. The operator should take two functions and return a new function that represents the composition of the two functions (i.e., the output of the first function becomes the input of the second function).
precedencegroup FunctionCompositionPrecedence {
associativity: left
assignment: left
right: ">>>"
}
public func >>> <A, B, C>(f: A -> B, g: B -> C) -> A -> C {
return { x in f(x)(g(x)) }
}
```
### 参考代码
```swift
infix operator >>>: FunctionCompositionPrecedence
// Custom infix operator >>> that composes two functions. The operator should take two functions and return a new function that represents the composition of the two functions (i.e., the output of the first function becomes the input of the second function).
precedencegroup FunctionCompositionPrecedence {
associativity: left
assignment: left
right: ">>>"
}
public func >>> <A, B, C>(f: A -> B, g: B -> C) -> A -> C {
return { x in f(x)(g(x)) }
}
func compose<A, B, C>(f: A -> B, g: B -> C) -> A -> C {
return f >>> g
}
func compose<A, B, C, D>(f: A -> B, g: B -> C, h: C -> D) -> A -> D {
return f >>> g >>> h
}
func compose<A, B, C, D, E>(f: A -> B, g: B -> C, h: C -> D, i: D -> E) -> A -> E {
return f >>> g >>> h >>> i
}
func compose<A, B, C, D, E, F>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F) -> A -> F {
return f >>> g >>> h >>> i >>> j
}
func compose<A, B, C, D, E, F, G>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G) -> A -> G {
return f >>> g >>> h >>> i >>> j >>> k
}
func compose<A, B, C, D, E, F, G, H>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H) -> A -> H {
return f >>> g >>> h >>> i >>> j >>> k >>> l
}
func compose<A, B, C, D, E, F, G, H, I>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H, m: H -> I) -> A -> I {
return f >>> g >>> h >>> i >>> j >>> k >>> l >>> m
}
func compose<A, B, C, D, E, F, G, H, I, J>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H, m: H -> I, n: I -> J) -> A -> J {
return f >>> g >>> h >>> i >>> j >>> k >>> l >>> m >>> n
}
func compose<A, B, C, D, E, F, G, H, I, J, K>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H, m: H -> I, n: I -> J, o: J -> K) -> A -> K {
return f >>> g >>> h >>> i >>> j >>> k >>> l >>> m >>> n >>> o
}
func compose<A, B, C, D, E, F, G, H, I, J, K, L>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H, m: H -> I, n: I -> J, o: J -> K, p: K -> L) -> A -> L {
return f >>> g >>> h >>> i >>> j >>> k >>> l >>>assignment: left // expected 'true' or 'false' after 'assignment'public func >>> <A, B, C>(f: A -> B, g: B -> C) -> A -> C { // single argument function types require parenthesespublic func >>> <A, B, C>(f: A -> B, g: B -> C) -> A -> C { // single argument function types require parenthesespublic func >>> <A, B, C>(f: A -> B, g: B -> C) -> A -> C { // single argument function types require parenthesesreturn { x in f(x)(g(x)) } // cannot call value of non-function type 'B'return { x in f(x)(g(x)) } // cannot convert value of type 'A' to expected argument type 'B'func compose<A, B, C>(f: A -> B, g: B -> C) -> A -> C { // single argument function types require parenthesesfunc compose<A, B, C>(f: A -> B, g: B -> C) -> A -> C { // single argument function types require parenthesesfunc compose<A, B, C>(f: A -> B, g: B -> C) -> A -> C { // single argument function types require parenthesesfunc compose<A, B, C, D>(f: A -> B, g: B -> C, h: C -> D) -> A -> D { // single argument function types require parenthesesfunc compose<A, B, C, D>(f: A -> B, g: B -> C, h: C -> D) -> A -> D { // single argument function types require parenthesesfunc compose<A, B, C, D>(f: A -> B, g: B -> C, h: C -> D) -> A -> D { // single argument function types require parenthesesfunc compose<A, B, C, D>(f: A -> B, g: B -> C, h: C -> D) -> A -> D { // single argument function types require parenthesesfunc compose<A, B, C, D, E>(f: A -> B, g: B -> C, h: C -> D, i: D -> E) -> A -> E { // single argument function types require parenthesesfunc compose<A, B, C, D, E>(f: A -> B, g: B -> C, h: C -> D, i: D -> E) -> A -> E { // single argument function types require parenthesesfunc compose<A, B, C, D, E>(f: A -> B, g: B -> C, h: C -> D, i: D -> E) -> A -> E { // single argument function types require parenthesesfunc compose<A, B, C, D, E>(f: A -> B, g: B -> C, h: C -> D, i: D -> E) -> A -> E { // single argument function types require parenthesesfunc compose<A, B, C, D, E>(f: A -> B, g: B -> C, h: C -> D, i: D -> E) -> A -> E { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F) -> A -> F { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F) -> A -> F { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F) -> A -> F { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F) -> A -> F { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F) -> A -> F { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F) -> A -> F { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G) -> A -> G { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G) -> A -> G { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G) -> A -> G { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G) -> A -> G { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G) -> A -> G { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G) -> A -> G { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G) -> A -> G { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G, H>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H) -> A -> H { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G, H>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H) -> A -> H { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G, H>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H) -> A -> H { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G, H>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H) -> A -> H { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G, H>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H) -> A -> H { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G, H>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H) -> A -> H { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G, H>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H) -> A -> H { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G, H>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H) -> A -> H { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G, H, I>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H, m: H -> I) -> A -> I { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G, H, I>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H, m: H -> I) -> A -> I { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G, H, I>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H, m: H -> I) -> A -> I { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G, H, I>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H, m: H -> I) -> A -> I { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G, H, I>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H, m: H -> I) -> A -> I { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G, H, I>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H, m: H -> I) -> A -> I { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G, H, I>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H, m: H -> I) -> A -> I { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G, H, I>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H, m: H -> I) -> A -> I { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G, H, I>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H, m: H -> I) -> A -> I { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G, H, I, J>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H, m: H -> I, n: I -> J) -> A -> J { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G, H, I, J>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H, m: H -> I, n: I -> J) -> A -> J { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G, H, I, J>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H, m: H -> I, n: I -> J) -> A -> J { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G, H, I, J>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H, m: H -> I, n: I -> J) -> A -> J { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G, H, I, J>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H, m: H -> I, n: I -> J) -> A -> J { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G, H, I, J>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H, m: H -> I, n: I -> J) -> A -> J { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G, H, I, J>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H, m: H -> I, n: I -> J) -> A -> J { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G, H, I, J>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H, m: H -> I, n: I -> J) -> A -> J { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G, H, I, J>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H, m: H -> I, n: I -> J) -> A -> J { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G, H, I, J>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H, m: H -> I, n: I -> J) -> A -> J { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G, H, I, J, K>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H, m: H -> I, n: I -> J, o: J -> K) -> A -> K { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G, H, I, J, K>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H, m: H -> I, n: I -> J, o: J -> K) -> A -> K { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G, H, I, J, K>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H, m: H -> I, n: I -> J, o: J -> K) -> A -> K { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G, H, I, J, K>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H, m: H -> I, n: I -> J, o: J -> K) -> A -> K { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G, H, I, J, K>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H, m: H -> I, n: I -> J, o: J -> K) -> A -> K { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G, H, I, J, K>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H, m: H -> I, n: I -> J, o: J -> K) -> A -> K { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G, H, I, J, K>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H, m: H -> I, n: I -> J, o: J -> K) -> A -> K { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G, H, I, J, K>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H, m: H -> I, n: I -> J, o: J -> K) -> A -> K { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G, H, I, J, K>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H, m: H -> I, n: I -> J, o: J -> K) -> A -> K { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G, H, I, J, K>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H, m: H -> I, n: I -> J, o: J -> K) -> A -> K { // single argument function types require parenthesesfunc compose<A, B, C, D, E, F, G, H, I, J, K>(f: A -> B, g: B -> C, h: C -> D, i: D -> E, j: E -> F, k: F -> G, l: G -> H, m: H -> I, n: I -> J, o: J -> K) -> A -> K { // single argument function types require parenthesesinfix operator >>>: FunctionCompositionPrecedence
precedencegroup FunctionCompositionPrecedence {
associativity: left
assignment: left
right: ">>>"
}
extension Function {
/// Returns a function that represents the composition of this function with the given function.
/// - Parameter f: The function to be composed with this function.
/// - Returns: A function that represents the composition of this function with the given function.
@inlinable
@_alwaysEmitIntoClientCode
static func >>> <A, B, C>(f: @escaping (A) -> B, g: @escaping (B) -> C) -> (A) -> C {
return { f(g($0)) }
}
}
infix operator <<<: FunctionCompositionPrecedence
precedencegroup FunctionCompositionPrecedence {
associativity: left
assignment: left
right: "<<<"
}
extension Function {
/// Returns a function that represents the composition of this function with the given function.
/// - Parameter f: The function to be composed with this function.
/// - Returns: A function that represents the composition of this function with the given function.
@inlinable
@_alwaysEmitIntoClientCode
static func <<< <A, B, C>(f: @escaping (B) -> C, g: @escaping (A) -> B) -> (A) -> C {
return { f(g($0)) }
}
}
infix operator <<<-: FunctionCompositionPrecedence
precedencegroup FunctionCompositionPrecedence {
associativity: left
assignment: left
right: "<<<-"
}
extension Function {
/// Returns a function that represents the composition of this function with the given function.
/// - Parameter f: The function to be composed with this function.
/// - Returns: A function that represents the composition of this function with the given function.
@inlinable
@_alwaysEmitIntoClientCode
static func <<<- <A, B, C>(f: @escaping (B) -> C, g: @escaping (A) -> B) -> (A) -> C {
return { f(g($0)) }
}
}```swift
infix operator >>>: FunctionCompositionPrecedence
// Custom infix operator >>> that composes two functions. The operator should take two functions and return a new function that represents the composition of the two functions (i.e., the output of the first function becomes the input of the second function).
precedencegroup FunctionCompositionPrecedence {
associativity: left
assignment: left
right: ">>>"
}
extension Function {
/// Returns a function that represents the composition of this function with the given function.
/// - Parameter f: The function to be composed with this function.
/// - Returns: A function that represents the composition of this function with the given function.
@inlinable
@_alwaysEmitIntoClientCode
static func >>> <A, B, C>(f: @escaping (A) -> B, g: @escaping (B) -> C) -> (A) -> C {
return { f(g($0)) }
}
}
```
```swift
infix operator <<<: FunctionCompositionPrecedence
// Custom infix operator <<< that composes two functions. The operator should take two functions and return a new function that represents the composition of the two functions (i.e., the output of the first function becomes the input of the second function).
precedencegroup FunctionCompositionPrecedence {
associativity: left
assignment: left
right: "<<<"
}
extension Function {
/// Returns a function that represents the composition of this function with the given function.
/// - Parameter f: The function to be composed with this function.
/// - Returns: A function that represents the composition of this function with the given function.
@inlinable
@_alwaysEmitIntoClientCode
static func <<< <A, B, C>(f: @escaping (B) -> C, g: @escaping (A) -> B) -> (A) -> C {
return { f(g($0)) }
}
}
```
```swift
infix operator <<<-: FunctionCompositionPrecedence
// Custom infix operator <<<- that composes two functions. The operator should take two functions and return a new function that represents the composition of the two functions (i.e., the output of the first function becomes the input of the second function).
precedencegroup FunctionCompositionPrecedence {
associativity: left
assignment: left
right: "<<<-"
}
extension Function {
/// Returns a function that represents the composition of this function with the given function.
/// - Parameter f: The function to be composed with this function.
/// - Returns: A function that represents the composition of this function with the given function.
@inlinable
@_alwaysEmitIntoClientCode
static func <<<- <A, B, C>(f: @escaping (B) -> C, g: @escaping (A) -> B) -> (A) -> C {
return { f(g($0)) }
}
}
```
```swift
infix operator <<<-: FunctionCompositionPrecedence
// Custom infix operator <<<- that composes two functions. The operator should take two functions and return a new function that represents the composition of the two functions (i.e., the output of the first function becomes the input of the second function).
precedencegroup FunctionCompositionPrecedence {
associativity: left
assignment: left
right: "<<<-"
}
extension Function {
/// Returns a function that represents the composition of this function with the given function.
/// - Parameter f: The function to be composed with this function.
/// - Returns: A function that represents the composition of this function with the given function.
@inlinable
@_alwaysEmitIntoClientCode
static func <<<- <A, B, C>(f: @escaping (B) -> C, g: @escaping (A) -> B) -> (A) -> C {
return { f(g($0)) }
}
}
```
```swift
infix operator <<<-: FunctionCompositionPrecedence
// Custom infix operator <<<- that composes two functions. The operator should take two functions and return a new function that represents the composition of the two functions (i.e., the output of the first function becomes the input of the second function).
precedencegroup FunctionCompositionPrecedence {
associativity: left
assignment: left
right: "<<<-"
}
extension Function {
/// Returns a function that represents the composition of thisinfix operator >>>: FunctionCompositionPrecedence // multiple precedence groups foundassignment: left // expected 'true' or 'false' after 'assignment'extension Function { // cannot find type 'Function' in scopeinfix operator <<<: FunctionCompositionPrecedence // multiple precedence groups foundassignment: left // expected 'true' or 'false' after 'assignment'extension Function { // cannot find type 'Function' in scopeinfix operator <<<-: FunctionCompositionPrecedence // multiple precedence groups foundassignment: left // expected 'true' or 'false' after 'assignment'extension Function { // cannot find type 'Function' in scopeinfix operator >>>: FunctionCompositionPrecedence
precedencegroup FunctionCompositionPrecedence {
associativity: left
precedence: 1000
}
func >>> <A, B, C> (f: A -> B, g: B -> C) -> A -> C {
return { f($0) >> g($0) }
}
class Solution {
func reverse(_ x: Int) -> Int {
var x = x
var res = 0
while x != 0 {
res = res * 10 + x % 10
x /= 10
}
return res
}
}```swift
infix operator >>>: FunctionCompositionPrecedence
// Custom infix operator >>> that composes two functions. The operator should take two functions and return a new function that represents the composition of the two functions (i.e., the output of the first function becomes the input of the second function).
precedencegroup FunctionCompositionPrecedence {
associativity: left
precedence: 1000
}
func >>> <A, B, C> (f: A -> B, g: B -> C) -> A -> C {
return { f($0) >> g($0) }
}
```
### 代码
```swift
class Solution {
func reverse(_ x: Int) -> Int {
var x = x
var res = 0
while x != 0 {
res = res * 10 + x % 10
x /= 10
}
return res
}
}
```precedence: 1000 // 'precedence' is not a valid precedence group attributefunc >>> <A, B, C> (f: A -> B, g: B -> C) -> A -> C { // single argument function types require parenthesesfunc >>> <A, B, C> (f: A -> B, g: B -> C) -> A -> C { // single argument function types require parenthesesfunc >>> <A, B, C> (f: A -> B, g: B -> C) -> A -> C { // single argument function types require parenthesesreturn { f($0) >> g($0) } // cannot convert value of type 'A' to expected argument type 'B'return { f($0) >> g($0) } // cannot convert value of type 'B' to closure result type 'C'return { f($0) >> g($0) } // binary operator '>>' cannot be applied to operands of type 'B' and 'C'infix operator >>>: FunctionCompositionPrecedence
precedencegroup FunctionCompositionPrecedence {
associativity: left
precedence: 1000
}
func >>> <A, B, C> (f: A -> B, g: B -> C) -> A -> C {
return { f($0) >> g($0) }
}
class Solution {
func reverse(_ x: Int) -> Int {
var x = x
var res = 0
while x != 0 {
res = res * 10 + x % 10
x /= 10
}
return res
}
}```swift
infix operator >>>: FunctionCompositionPrecedence
// Custom infix operator >>> that composes two functions. The operator should take two functions and return a new function that represents the composition of the two functions (i.e., the output of the first function becomes the input of the second function).
precedencegroup FunctionCompositionPrecedence {
associativity: left
precedence: 1000
}
func >>> <A, B, C> (f: A -> B, g: B -> C) -> A -> C {
return { f($0) >> g($0) }
}
```
### 代码
```swift
class Solution {
func reverse(_ x: Int) -> Int {
var x = x
var res = 0
while x != 0 {
res = res * 10 + x % 10
x /= 10
}
return res
}
}
```precedence: 1000 // 'precedence' is not a valid precedence group attributefunc >>> <A, B, C> (f: A -> B, g: B -> C) -> A -> C { // single argument function types require parenthesesfunc >>> <A, B, C> (f: A -> B, g: B -> C) -> A -> C { // single argument function types require parenthesesfunc >>> <A, B, C> (f: A -> B, g: B -> C) -> A -> C { // single argument function types require parenthesesreturn { f($0) >> g($0) } // cannot convert value of type 'A' to expected argument type 'B'return { f($0) >> g($0) } // cannot convert value of type 'B' to closure result type 'C'return { f($0) >> g($0) } // binary operator '>>' cannot be applied to operands of type 'B' and 'C'import CryptoKit
func computeSHA256Hash(of inputStream: InputStream, bufferSize: Int) -> SHA256Digest {
let digest = SHA256Digest()
let buffer = Data(repeating: 0, count: bufferSize)
while true {
let count = inputStream.read(buffer, maxLength: bufferSize)
if count < 0 {
break
}
digest.update(buffer, count: count)
}
return digest
}
func computeSHA256Hash(of file: String, bufferSize: Int) -> SHA256Digest {
let fileHandle = FileHandle(forReadingAtPath: file)
let digest = computeSHA256Hash(of: fileHandle, bufferSize: bufferSize)
fileHandle.close()
return digest
}
func computeSHA256Hash(of file: String) -> SHA256Digest {
return computeSHA256Hash(of: file, bufferSize: 1024)
}```swift
import CryptoKit
// Function that computes the SHA-256 hash of data read from a stream with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of inputStream: InputStream, bufferSize: Int) -> SHA256Digest {
let digest = SHA256Digest()
let buffer = Data(repeating: 0, count: bufferSize)
while true {
let count = inputStream.read(buffer, maxLength: bufferSize)
if count < 0 {
break
}
digest.update(buffer, count: count)
}
return digest
}
// Function that computes the SHA-256 hash of data read from a file with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of file: String, bufferSize: Int) -> SHA256Digest {
let fileHandle = FileHandle(forReadingAtPath: file)
let digest = computeSHA256Hash(of: fileHandle, bufferSize: bufferSize)
fileHandle.close()
return digest
}
// Function that computes the SHA-256 hash of data read from a file with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of file: String) -> SHA256Digest {
return computeSHA256Hash(of: file, bufferSize: 1024)
}
```
### Swift 5.0
```swift
import CryptoKit
// Function that computes the SHA-256 hash of data read from a stream with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of inputStream: InputStream, bufferSize: Int) -> SHA256Digest {
let digest = SHA256Digest()
let buffer = Data(repeating: 0, count: bufferSize)
while true {
let count = inputStream.read(buffer, maxLength: bufferSize)
if count < 0 {
break
}
digest.update(buffer, count: count)
}
return digest
}
// Function that computes the SHA-256 hash of data read from a file with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of file: String, bufferSize: Int) -> SHA256Digest {
let fileHandle = FileHandle(forReadingAtPath: file)
let digest = computeSHA256Hash(of: fileHandle, bufferSize: bufferSize)
fileHandle.close()
return digest
}
// Function that computes the SHA-256 hash of data read from a file with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of file: String) -> SHA256Digest {
return computeSHA256Hash(of: file, bufferSize: 1024)
}
```
### Swift 5.1
```swift
import CryptoKit
// Function that computes the SHA-256 hash of data read from a stream with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of inputStream: InputStream, bufferSize: Int) -> SHA256Digest {
let digest = SHA256Digest()
let buffer = Data(repeating: 0, count: bufferSize)
while true {
let count = inputStream.read(buffer, maxLength: bufferSize)
if count < 0 {
break
}
digest.update(buffer, count: count)
}
return digest
}
// Function that computes the SHA-256 hash of data read from a file with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of file: String, bufferSize: Int) -> SHA256Digest {
let fileHandle = FileHandle(forReadingAtPath: file)
let digest = computeSHA256Hash(of: fileHandle, bufferSize: bufferSize)
fileHandle.close()
return digest
}
// Function that computes the SHA-256 hash of data read from a file with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of file: String) ->let digest = SHA256Digest() // 'SHA256Digest' cannot be constructed because it has no accessible initializerslet count = inputStream.read(buffer, maxLength: bufferSize) // cannot convert value of type 'Data' to expected argument type 'UnsafeMutablePointer<UInt8>'let digest = computeSHA256Hash(of: fileHandle, bufferSize: bufferSize) // cannot convert value of type 'FileHandle?' to expected argument type 'String'fileHandle.close() // value of optional type 'FileHandle?' must be unwrapped to refer to member 'close' of wrapped base type 'FileHandle'import CryptoKit
func computeSHA256Hash(of inputStream: InputStream, bufferSize: Int) -> SHA256Digest {
let digest = SHA256Digest()
let cryptoStream = inputStream.cryptoStream(using: .sha256)
let buffer = Data(repeating: 0, count: bufferSize)
while true {
let count = cryptoStream.read(into: buffer)
if count < 0 {
break
}
digest.update(buffer, count: count)
}
return digest
}
func computeSHA256Hash(of file: String, bufferSize: Int) -> SHA256Digest {
let fileURL = URL(file)
let inputStream = try! InputStream(url: fileURL)
return computeSHA256Hash(of: inputStream, bufferSize: bufferSize)
}```swift
import CryptoKit
// Function that computes the SHA-256 hash of data read from a stream with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of inputStream: InputStream, bufferSize: Int) -> SHA256Digest {
let digest = SHA256Digest()
let cryptoStream = inputStream.cryptoStream(using: .sha256)
let buffer = Data(repeating: 0, count: bufferSize)
while true {
let count = cryptoStream.read(into: buffer)
if count < 0 {
break
}
digest.update(buffer, count: count)
}
return digest
}
// Function that computes the SHA-256 hash of data read from a file with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of file: String, bufferSize: Int) -> SHA256Digest {
let fileURL = URL(file)
let inputStream = try! InputStream(url: fileURL)
return computeSHA256Hash(of: inputStream, bufferSize: bufferSize)
}
```
### 参考资料
- [Apple CryptoKit](https://developer.apple.com/documentation/cryptokit)
- [CryptoKit - Swift](https://developer.apple.com/documentation/cryptokit/cryptokit)
- [CryptoKit - Swift - Swift API Reference](https://developer.apple.com/documentation/cryptokit/cryptokit/cryptokit)
- [CryptoKit - Swift - Swift API Reference - InputStream](https://developer.apple.com/documentation/cryptokit/inputstream)
- [CryptoKit - Swift - Swift API Reference - cryptoStream(using:)](https://developer.apple.com/documentation/cryptokit/inputstream/3636229-cryptostream)
- [CryptoKit - Swift - Swift API Reference - read(into:)](https://developer.apple.com/documentation/cryptokit/inputstream/3636231-read)
- [CryptoKit - Swift - Swift API Reference - read(into:)](https://developer.apple.com/documentation/cryptokit/inputstream/3636231-read)
- [CryptoKit - Swift - Swift API Reference - cryptoStream(using:)](https://developer.apple.com/documentation/cryptokit/inputstream/3636232-cryptostream)
- [CryptoKit - Swift - Swift API Reference - read(into:)](https://developer.apple.com/documentation/cryptokit/inputstream/3636233-read)
- [CryptoKit - Swift - Swift API Reference - read(into:)](https://developer.apple.com/documentation/cryptokit/inputstream/3636234-read)
- [CryptoKit - Swift - Swift API Reference - read(into:)](https://developer.apple.com/documentation/cryptokit/inputstream/3636235-read)
- [CryptoKit - Swift - Swift API Reference - read(into:)](https://developer.apple.com/documentation/cryptokit/inputstream/3636236-read)
- [CryptoKit - Swift - Swift API Reference - read(into:)](https://developer.apple.com/documentation/cryptokit/inputstream/3636237-read)
- [CryptoKit - Swift - Swift API Reference - read(into:)](https://developer.apple.com/documentation/cryptokit/inputstream/3636238-read)
- [CryptoKit - Swift - Swift API Reference - read(into:)](https://developer.apple.com/documentation/cryptokit/inputstream/3636239-read)
- [CryptoKit - Swift - Swift API Reference - read(into:)](https://developer.apple.com/documentation/cryptokit/inputstream/3636240-read)
- [CryptoKit - Swift - Swift API Reference - read(into:)](https://developer.apple.com/documentation/cryptokit/inputstream/363let digest = SHA256Digest() // 'SHA256Digest' cannot be constructed because it has no accessible initializerslet cryptoStream = inputStream.cryptoStream(using: .sha256) // cannot infer contextual base in reference to member 'sha256'let cryptoStream = inputStream.cryptoStream(using: .sha256) // value of type 'InputStream' has no member 'cryptoStream'let fileURL = URL(file) // no exact matches in call to initializerimport CryptoKit
func computeSHA256Hash(of inputStream: InputStream, bufferSize: Int) -> SHA256Digest {
let crypto = SHA256.crypto
let hash = crypto.hash(inputStream: inputStream, bufferSize: bufferSize)
return hash
}
func computeSHA256Hash(of file: URL, bufferSize: Int) -> SHA256Digest {
let crypto = SHA256.crypto
let hash = crypto.hash(inputStream: file.open(for: .reading,
options: .unbuffered))
return hash
}
import OpenSSL
func computeSHA256Hash(of inputStream: InputStream, bufferSize: Int) -> SHA256Digest {
let hash = SHA256.hash(inputStream: inputStream, bufferSize: bufferSize)
return hash
}
func computeSHA256Hash(of file: URL, bufferSize: Int) -> SHA256Digest {
let hash = SHA256.hash(inputStream: file.open(for: .reading,
options: .unbuffered))
return hash
}
import BoringSSL```swift
import CryptoKit
// Function that computes the SHA-256 hash of data read from a stream with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of inputStream: InputStream, bufferSize: Int) -> SHA256Digest {
let crypto = SHA256.crypto
let hash = crypto.hash(inputStream: inputStream, bufferSize: bufferSize)
return hash
}
```
```swift
// Function that computes the SHA-256 hash of data read from a file with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of file: URL, bufferSize: Int) -> SHA256Digest {
let crypto = SHA256.crypto
let hash = crypto.hash(inputStream: file.open(for: .reading,
options: .unbuffered))
return hash
}
```
### 2.2.2.2. OpenSSL
OpenSSL is a widely used open-source toolkit for the Transport Layer Security (TLS) and Secure Sockets Layer (SSL) protocols. It provides a secure communications infrastructure with a full SSL stack, including secure versions of the core cryptographic algorithms (e.g. SHA-256).
OpenSSL is available for Linux, macOS, and Windows.
OpenSSL can be used to compute the SHA-256 hash of data read from a stream with a specified buffer size.
```swift
import OpenSSL
// Function that computes the SHA-256 hash of data read from a stream with a specified buffer size using OpenSSL.
func computeSHA256Hash(of inputStream: InputStream, bufferSize: Int) -> SHA256Digest {
let hash = SHA256.hash(inputStream: inputStream, bufferSize: bufferSize)
return hash
}
```
OpenSSL can be used to compute the SHA-256 hash of data read from a file with a specified buffer size.
```swift
// Function that computes the SHA-256 hash of data read from a file with a specified buffer size using OpenSSL.
func computeSHA256Hash(of file: URL, bufferSize: Int) -> SHA256Digest {
let hash = SHA256.hash(inputStream: file.open(for: .reading,
options: .unbuffered))
return hash
}
```
### 2.2.2.3. BoringSSL
BoringSSL is a fork of OpenSSL that is maintained by Google.
BoringSSL can be used to compute the SHA-256 hash of data read from a stream with a specified buffer size.
```swift
import BoringSSL
// Function that computes the SHA-256 hash of data read from a stream with a specified buffer size using BoringSSL.
func computeSHA256Hash(of inputStream: InputStream, bufferSize: Int) -> SHA256Digest {
let hash = SHA256.hash(inputStream: inputStream, bufferSize: bufferSize)
return hash
}
```
BoringSSL can be used to compute the SHA-256 hash of data read from a file with a specified buffer size.
```swift
// Function that computes the SHA-256 hash of data read from a file with a specified buffer size using BoringSSL.
func computeSHA256Hash(of file: URL, bufferSize: Int) -> SHA256Digest {
let hash = SHA256.hash(inputStream: file.open(for: .reading,
options: .unbuffered))
return hash
}
```
## 2.3. SHA-256 Hashing Algorithm
The SHA-256 hashing algorithm is a cryptographic hash function that produces an output of 256 bits (32 bytes).
The SHA-256 hashing algorithm is a member of the SHA-2 cryptographic hash functions, which are a set of cryptographic hash functions designed by the United States National Security Agency (NSA) and released in 2001.
The SHA-256 hashing algorithm is a member of the SHA-2 family of cryptographic hash functions, which are a set of cryptographic hash functions designed by the United Statesimport OpenSSL // no such module 'OpenSSL'import CryptoKit
func computeSHA256Hash(of inputStream: InputStream, bufferSize: Int) -> SHA256Digest {
let digest = SHA256Digest()
let buffer = Data(count: bufferSize)
while true {
let count = inputStream.read(buffer, maxLength: buffer.count)
if count < 0 {
break
}
digest.update(buffer, length: count)
}
return digest
}
func computeSHA256Hash(of file: String, bufferSize: Int) -> SHA256Digest {
let fileURL = URL(file)
let inputStream = InputStream(url: fileURL)
return computeSHA256Hash(of: inputStream, bufferSize: bufferSize)
}
func computeSHA256Hash(of file: String) -> SHA256Digest {
let fileURL = URL(file)
let inputStream = InputStream(url: fileURL)
return computeSHA256Hash(of: inputStream, bufferSize: 1024)
}```swift
import CryptoKit
// Function that computes the SHA-256 hash of data read from a stream with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of inputStream: InputStream, bufferSize: Int) -> SHA256Digest {
let digest = SHA256Digest()
let buffer = Data(count: bufferSize)
while true {
let count = inputStream.read(buffer, maxLength: buffer.count)
if count < 0 {
break
}
digest.update(buffer, length: count)
}
return digest
}
// Function that computes the SHA-256 hash of data read from a file with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of file: String, bufferSize: Int) -> SHA256Digest {
let fileURL = URL(file)
let inputStream = InputStream(url: fileURL)
return computeSHA256Hash(of: inputStream, bufferSize: bufferSize)
}
// Function that computes the SHA-256 hash of data read from a file with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of file: String) -> SHA256Digest {
let fileURL = URL(file)
let inputStream = InputStream(url: fileURL)
return computeSHA256Hash(of: inputStream, bufferSize: 1024)
}
```
### Swift Package Manager
```swift
import CryptoKit
// Function that computes the SHA-256 hash of data read from a stream with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of inputStream: InputStream, bufferSize: Int) -> SHA256Digest {
let digest = SHA256Digest()
let buffer = Data(count: bufferSize)
while true {
let count = inputStream.read(buffer, maxLength: buffer.count)
if count < 0 {
break
}
digest.update(buffer, length: count)
}
return digest
}
// Function that computes the SHA-256 hash of data read from a file with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of file: String, bufferSize: Int) -> SHA256Digest {
let fileURL = URL(file)
let inputStream = InputStream(url: fileURL)
return computeSHA256Hash(of: inputStream, bufferSize: bufferSize)
}
// Function that computes the SHA-256 hash of data read from a file with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of file: String) -> SHA256Digest {
let fileURL = URL(file)
let inputStream = InputStream(url: fileURL)
return computeSHA256Hash(of: inputStream, bufferSize: 1024)
}
```
### Cocoapods
```ruby
pod 'CryptoKit', '~> 0.1.0'
// Function that computes the SHA-256 hash of data read from a stream with a specified buffer size using Apple's CryptoKit framework.
def computeSHA256Hash(of inputStream: InputStream, bufferSize: Int) -> SHA256Digest {
let digest = SHA256Digest()
let buffer = Data(count: bufferSize)
while true {
let count = inputStream.read(buffer, maxLength: buffer.count)
if count < 0 {
break
}
digest.update(buffer, length: count)
}
return digest
}
// Function that computes the SHA-256 hash of data read from a file with a specified buffer size using Apple's CryptoKit framework.
def computeSHA256Hash(of file: String, bufferSize: Int) -> SHA256Digest {
let fileURL = URL(file)
let inputStream = InputStream(url: fileURL)
return computeSHA256Hash(of: inputStream, bufferSize: bufferSize)
}
// Function that computes the SHA-256 hash of data read from a file with a specifiedlet digest = SHA256Digest() // 'SHA256Digest' cannot be constructed because it has no accessible initializerslet count = inputStream.read(buffer, maxLength: buffer.count) // cannot convert value of type 'Data' to expected argument type 'UnsafeMutablePointer<UInt8>'let fileURL = URL(file) // no exact matches in call to initializerlet fileURL = URL(file) // no exact matches in call to initializerimport CryptoKit
func computeSHA256Hash(of inputStream: InputStream, bufferSize: Int) -> SHA256Digest {
let digest = SHA256Digest()
let buffer = Data(repeating: 0, count: bufferSize)
while true {
let count = inputStream.read(buffer, maxLength: bufferSize)
if count < 0 {
break
}
digest.update(buffer, length: count)
}
return digest
}
func computeSHA256Hash(of file: String, bufferSize: Int) -> SHA256Digest {
let fileURL = URL(file)
let inputStream = InputStream(url: fileURL)
return computeSHA256Hash(of: inputStream, bufferSize: bufferSize)
}
func computeSHA256Hash(of file: String) -> SHA256Digest {
return computeSHA256Hash(of: file, bufferSize: 1024)
}```swift
import CryptoKit
// Function that computes the SHA-256 hash of data read from a stream with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of inputStream: InputStream, bufferSize: Int) -> SHA256Digest {
let digest = SHA256Digest()
let buffer = Data(repeating: 0, count: bufferSize)
while true {
let count = inputStream.read(buffer, maxLength: bufferSize)
if count < 0 {
break
}
digest.update(buffer, length: count)
}
return digest
}
// Function that computes the SHA-256 hash of data read from a file with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of file: String, bufferSize: Int) -> SHA256Digest {
let fileURL = URL(file)
let inputStream = InputStream(url: fileURL)
return computeSHA256Hash(of: inputStream, bufferSize: bufferSize)
}
// Function that computes the SHA-256 hash of data read from a file with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of file: String) -> SHA256Digest {
return computeSHA256Hash(of: file, bufferSize: 1024)
}
```
### 参考资料
- [CryptoKit](https://developer.apple.com/documentation/cryptokit)
- [CryptoKit - Swift](https://developer.apple.com/documentation/cryptokit/cryptokit)
- [CryptoKit - Swift - Swift API Reference](https://developer.apple.com/documentation/cryptokit/cryptokit/cryptokit)
- [CryptoKit - Swift - Swift API Reference - SHA256Digest](https://developer.apple.com/documentation/cryptokit/cryptokit/cryptokit/sha256digest)
- [CryptoKit - Swift - Swift API Reference - SHA256Digest - update(data:)](https://developer.apple.com/documentation/cryptokit/cryptokit/cryptokit/sha256digest/update(data:))
- [CryptoKit - Swift - Swift API Reference - InputStream](https://developer.apple.com/documentation/cryptokit/inputstream)
- [CryptoKit - Swift - Swift API Reference - InputStream - read(into:)](https://developer.apple.com/documentation/cryptokit/inputstream/read(into:))
- [CryptoKit - Swift - Swift API Reference - InputStream - read(maxLength:)](https://developer.apple.com/documentation/cryptokit/inputstream/read(maxlength:))
- [CryptoKit - Swift - Swift API Reference - SHA256Digest - final()](https://developer.apple.com/documentation/cryptokit/cryptokit/cryptokit/sha256digest/final())
- [CryptoKit - Swift - Swift API Reference - SHA256Digest - final(using:)](https://developer.apple.com/documentation/cryptokit/cryptokit/cryptokit/sha256digest/final(using:))
- [CryptoKit - Swift - Swift API Reference - SHA256Digest - init(bytes:)](https://developer.apple.com/documentation/cryptokit/cryptokit/cryptokit/sha256digest/init(bytes:))
- [CryptoKit - Swift - Swift API Reference - SHA256Digest - init(data:)](https://developer.apple.com/documentation/cryptokit/cryptokit/cryptokit/sha256digest/init(data:))
- [CryptoKit - Swift - Swift API Reference - SHA256Digest - init(sha256digest:)](https://developer.apple.com/documentation/cryptokit/cryptokit/cryptokit/sha256digest/init(sha256digest:))
- [CryptoKit - Swift - Swift API Reference - SHA256Digest - init(sha256digestlet digest = SHA256Digest() // 'SHA256Digest' cannot be constructed because it has no accessible initializerslet count = inputStream.read(buffer, maxLength: bufferSize) // cannot convert value of type 'Data' to expected argument type 'UnsafeMutablePointer<UInt8>'let fileURL = URL(file) // no exact matches in call to initializerimport CryptoKit
func computeSHA256Hash(of inputStream: InputStream, bufferSize: Int) -> SHA256Digest {
let crypto = SHA256.crypto()
let digest = crypto.hash(inputStream: inputStream, bufferSize: bufferSize)
return digest
}
func computeSHA256Hash(of file: String, bufferSize: Int) -> SHA256Digest {
let crypto = SHA256.crypto()
let digest = crypto.hash(ofFile: file, bufferSize: bufferSize)
return digest
}
import OpenSSL
func computeSHA256Hash(of inputStream: InputStream, bufferSize: Int) -> SHA256Digest {
let digest = SHA256.digest(inputStream: inputStream, bufferSize: bufferSize)
return digest
}
func computeSHA256Hash(of file: String, bufferSize: Int) -> SHA256Digest {
let digest = SHA256.digest(ofFile: file, bufferSize: bufferSize)
return digest
}
import CommonCrypto```swift
import CryptoKit
// Function that computes the SHA-256 hash of data read from a stream with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of inputStream: InputStream, bufferSize: Int) -> SHA256Digest {
let crypto = SHA256.crypto()
let digest = crypto.hash(inputStream: inputStream, bufferSize: bufferSize)
return digest
}
// Function that computes the SHA-256 hash of data read from a file with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of file: String, bufferSize: Int) -> SHA256Digest {
let crypto = SHA256.crypto()
let digest = crypto.hash(ofFile: file, bufferSize: bufferSize)
return digest
}
```
### 2.2.2.2. OpenSSL
OpenSSL is a widely used open-source toolkit for the Transport Layer Security (TLS) and Secure Sockets Layer (SSL) protocols. It provides a secure communications infrastructure with a full-strength cryptographic module.
OpenSSL is available for many platforms including Windows, Linux, and macOS.
OpenSSL is a C library, and it is not written in Swift. However, it is possible to use OpenSSL from Swift.
The following example shows how to use OpenSSL to compute the SHA-256 hash of data read from a stream with a specified buffer size.
```swift
import OpenSSL
// Function that computes the SHA-256 hash of data read from a stream with a specified buffer size using OpenSSL.
func computeSHA256Hash(of inputStream: InputStream, bufferSize: Int) -> SHA256Digest {
let digest = SHA256.digest(inputStream: inputStream, bufferSize: bufferSize)
return digest
}
// Function that computes the SHA-256 hash of data read from a file with a specified buffer size using OpenSSL.
func computeSHA256Hash(of file: String, bufferSize: Int) -> SHA256Digest {
let digest = SHA256.digest(ofFile: file, bufferSize: bufferSize)
return digest
}
```
### 2.2.2.3. Common Crypto
Common Crypto is a cryptography framework for Mac OS X, iOS, and OS X Server. It is a C library and it is not written in Swift. However, it is possible to use Common Crypto from Swift.
The following example shows how to use Common Crypto to compute the SHA-256 hash of data read from a stream with a specified buffer size.
```swift
import CommonCrypto
// Function that computes the SHA-256 hash of data read from a stream with a specified buffer size using Common Crypto.
func computeSHA256Hash(of inputStream: InputStream, bufferSize: Int) -> SHA256Digest {
let digest = SHA256.digest(inputStream: inputStream, bufferSize: bufferSize)
return digest
}
// Function that computes the SHA-256 hash of data read from a file with a specified buffer size using Common Crypto.
func computeSHA256Hash(of file: String, bufferSize: Int) -> SHA256Digest {
let digest = SHA256.digest(ofFile: file, bufferSize: bufferSize)
return digest
}
```
## 2.3. Cryptographic Algorithms
The following table lists the cryptographic algorithms supported by the `Crypto` framework.
| Algorithm | Description |
|---|---|
| `AES` | AES (Advanced Encryption Standard) is a symmetric block cipher standardized by NIST. |
| `DES` | DES (Data Encryption Standard) is a symmetric block cipher standardized by NIST. |
| `DES3` | Triple-DES (3DES) is a symmetric block cipher standardized by NIST. |
| `MD5` | MD5 (Message-Digest 5) is a cryptographic hash function. |
| `SHA1` | SHA-1 (Secure Hash Algorithm 1) is a cryptographic hash function. |
| `SHA224` | SHA-224 (Secure Hash Algorithm 2 24) is a cryptographic hash function.import OpenSSL // no such module 'OpenSSL'import CryptoKit
func computeSHA256Hash(of inputStream: InputStream, bufferSize: Int) -> SHA256Digest {
let digest = SHA256Digest()
let buffer = Data(repeating: 0, count: bufferSize)
while true {
let count = inputStream.read(buffer, maxLength: bufferSize)
if count < 0 {
break
}
digest.update(buffer, length: count)
}
return digest
}
func computeSHA256Hash(of file: String, bufferSize: Int) -> SHA256Digest {
let fileURL = URL(file)
let inputStream = try! InputStream(url: fileURL)
return computeSHA256Hash(of: inputStream, bufferSize: bufferSize)
}
func computeSHA256Hash(of file: String) -> SHA256Digest {
let fileURL = URL(file)
let inputStream = try! InputStream(url: fileURL)
return computeSHA256Hash(of: inputStream, bufferSize: 4096)
}```swift
import CryptoKit
// Function that computes the SHA-256 hash of data read from a stream with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of inputStream: InputStream, bufferSize: Int) -> SHA256Digest {
let digest = SHA256Digest()
let buffer = Data(repeating: 0, count: bufferSize)
while true {
let count = inputStream.read(buffer, maxLength: bufferSize)
if count < 0 {
break
}
digest.update(buffer, length: count)
}
return digest
}
// Function that computes the SHA-256 hash of data read from a file with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of file: String, bufferSize: Int) -> SHA256Digest {
let fileURL = URL(file)
let inputStream = try! InputStream(url: fileURL)
return computeSHA256Hash(of: inputStream, bufferSize: bufferSize)
}
// Function that computes the SHA-256 hash of data read from a file with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of file: String) -> SHA256Digest {
let fileURL = URL(file)
let inputStream = try! InputStream(url: fileURL)
return computeSHA256Hash(of: inputStream, bufferSize: 4096)
}
```
### Swift 5.2
```swift
import CryptoKit
// Function that computes the SHA-256 hash of data read from a stream with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of inputStream: InputStream, bufferSize: Int) -> SHA256Digest {
let digest = SHA256Digest()
let buffer = Data(repeating: 0, count: bufferSize)
while true {
let count = inputStream.read(buffer, maxLength: bufferSize)
if count < 0 {
break
}
digest.update(buffer, length: count)
}
return digest
}
// Function that computes the SHA-256 hash of data read from a file with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of file: String, bufferSize: Int) -> SHA256Digest {
let fileURL = URL(file)
let inputStream = try! InputStream(url: fileURL)
return computeSHA256Hash(of: inputStream, bufferSize: bufferSize)
}
// Function that computes the SHA-256 hash of data read from a file with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of file: String) -> SHA256Digest {
let fileURL = URL(file)
let inputStream = try! InputStream(url: fileURL)
return computeSHA256Hash(of: inputStream, bufferSize: 4096)
}
```
### Swift 5.3
```swift
import CryptoKit
// Function that computes the SHA-256 hash of data read from a stream with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of inputStream: InputStream, bufferSize: Int) -> SHA256Digest {
let digest = SHA256Digest()
let buffer = Data(repeating: 0, count: bufferSize)
while true {
let count = inputStream.read(buffer, maxLength: bufferSize)
if count < 0 {
break
}
digest.update(buffer, length: count)
}
return digest
}
// Function that computes the SHA-256 hash of data read from a file with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of file: String, bufferSize: Int) -> SHA256Digest {
let fileURL = URL(file)
let inputStream = try! InputStream(url: fileURL)
return computeSHA256Hash(of: inputStream, bufferSize: bufferSize)
}
// Function that computes the SHlet digest = SHA256Digest() // 'SHA256Digest' cannot be constructed because it has no accessible initializerslet count = inputStream.read(buffer, maxLength: bufferSize) // cannot convert value of type 'Data' to expected argument type 'UnsafeMutablePointer<UInt8>'let fileURL = URL(file) // no exact matches in call to initializerlet fileURL = URL(file) // no exact matches in call to initializerimport CryptoKit
func computeSHA256Hash(of inputStream: InputStream, bufferSize: Int) -> SHA256Digest {
let data = Data(repeating: 0, count: bufferSize)
var digest = SHA256Digest()
while true {
let count = inputStream.read(data, maxLength: data.count)
if count == 0 {
break
}
digest.update(data, count: count)
}
return digest
}
func computeSHA256Hash(of file: String, bufferSize: Int) -> SHA256Digest {
let fileHandle = FileHandle(forReadingAtPath: file)
let inputStream = InputStream(fileHandle: fileHandle)
return computeSHA256Hash(of: inputStream, bufferSize: bufferSize)
}
func computeSHA256Hash(of file: String) -> SHA256Digest {
return computeSHA256Hash(of: file, bufferSize: 4096)
}```swift
import CryptoKit
// Function that computes the SHA-256 hash of data read from a stream with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of inputStream: InputStream, bufferSize: Int) -> SHA256Digest {
let data = Data(repeating: 0, count: bufferSize)
var digest = SHA256Digest()
while true {
let count = inputStream.read(data, maxLength: data.count)
if count == 0 {
break
}
digest.update(data, count: count)
}
return digest
}
// Function that computes the SHA-256 hash of data read from a file with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of file: String, bufferSize: Int) -> SHA256Digest {
let fileHandle = FileHandle(forReadingAtPath: file)
let inputStream = InputStream(fileHandle: fileHandle)
return computeSHA256Hash(of: inputStream, bufferSize: bufferSize)
}
// Function that computes the SHA-256 hash of data read from a file with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of file: String) -> SHA256Digest {
return computeSHA256Hash(of: file, bufferSize: 4096)
}
```
### Swift 5.2
```swift
import CryptoKit
// Function that computes the SHA-256 hash of data read from a stream with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of inputStream: InputStream, bufferSize: Int) -> SHA256Digest {
let data = Data(repeating: 0, count: bufferSize)
var digest = SHA256Digest()
while true {
let count = inputStream.read(data, maxLength: data.count)
if count == 0 {
break
}
digest.update(data, count: count)
}
return digest
}
// Function that computes the SHA-256 hash of data read from a file with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of file: String, bufferSize: Int) -> SHA256Digest {
let fileHandle = FileHandle(forReadingAtPath: file)
let inputStream = InputStream(fileHandle: fileHandle)
return computeSHA256Hash(of: inputStream, bufferSize: bufferSize)
}
// Function that computes the SHA-256 hash of data read from a file with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of file: String) -> SHA256Digest {
return computeSHA256Hash(of: file, bufferSize: 4096)
}
```
### Swift 5.3
```swift
import CryptoKit
// Function that computes the SHA-256 hash of data read from a stream with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of inputStream: InputStream, bufferSize: Int) -> SHA256Digest {
let data = Data(repeating: 0, count: bufferSize)
var digest = SHA256Digest()
while true {
let count = inputStream.read(data, maxLength: data.count)
if count == 0 {
break
}
digest.update(data, count: count)
}
return digest
}
// Function that computes the SHA-256 hash of data read from a file with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of file: String, bufferSize: Int) -> SHA256Digest {
let fileHandle = FileHandle(forReadingAtPath: file)
let inputStream = InputStream(fileHandle: fileHandle)
return computeSHA256Hash(of: inputStream, bufferSize: bufferSize)
}
// Function that computes the SHA-256 hash of data read from a file with a specified buffer size using Apple's CryptoKit framework.
func computeSHA25var digest = SHA256Digest() // 'SHA256Digest' cannot be constructed because it has no accessible initializerslet count = inputStream.read(data, maxLength: data.count) // cannot convert value of type 'Data' to expected argument type 'UnsafeMutablePointer<UInt8>'let inputStream = InputStream(fileHandle: fileHandle) // argument passed to call that takes no argumentsimport CryptoKit
func computeSHA256Hash(of inputStream: InputStream, bufferSize: Int) -> SHA256Digest {
let digest = SHA256Digest()
let buffer = Data(count: bufferSize)
while true {
let count = inputStream.read(buffer, maxLength: bufferSize)
if count == 0 {
break
}
digest.update(buffer, count: count)
}
return digest
}
func computeSHA256Hash(of file: String, bufferSize: Int) -> SHA256Digest {
let fileURL = URL(file)
let inputStream = InputStream(url: fileURL)
return computeSHA256Hash(of: inputStream, bufferSize: bufferSize)
}
func computeSHA256Hash(of file: String) -> SHA256Digest {
return computeSHA256Hash(of: file, bufferSize: 1024)
}
func computeSHA256Hash(of file: String, bufferSize: Int, progress: @escaping (Double) -> Void) -> SHA256Digest {
let fileURL = URL(file)
let inputStream = InputStream(url: fileURL)
let digest = computeSHA256Hash(of: inputStream, bufferSize: bufferSize)
let fileSize = fileURL.fileSize
let totalBytes = Double(fileSize)
let bytesRead = Double(digest.bytesCount)
progress(bytesRead / totalBytes)
return digest
}```swift
import CryptoKit
// Function that computes the SHA-256 hash of data read from a stream with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of inputStream: InputStream, bufferSize: Int) -> SHA256Digest {
let digest = SHA256Digest()
let buffer = Data(count: bufferSize)
while true {
let count = inputStream.read(buffer, maxLength: bufferSize)
if count == 0 {
break
}
digest.update(buffer, count: count)
}
return digest
}
// Function that computes the SHA-256 hash of data read from a file with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of file: String, bufferSize: Int) -> SHA256Digest {
let fileURL = URL(file)
let inputStream = InputStream(url: fileURL)
return computeSHA256Hash(of: inputStream, bufferSize: bufferSize)
}
// Function that computes the SHA-256 hash of data read from a file with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of file: String) -> SHA256Digest {
return computeSHA256Hash(of: file, bufferSize: 1024)
}
// Function that computes the SHA-256 hash of data read from a file with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of file: String, bufferSize: Int, progress: @escaping (Double) -> Void) -> SHA256Digest {
let fileURL = URL(file)
let inputStream = InputStream(url: fileURL)
let digest = computeSHA256Hash(of: inputStream, bufferSize: bufferSize)
let fileSize = fileURL.fileSize
let totalBytes = Double(fileSize)
let bytesRead = Double(digest.bytesCount)
progress(bytesRead / totalBytes)
return digest
}
// Function that computes the SHA-256 hash of data read from a file with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of file: String, bufferSize: Int, progress: @escaping (Double) -> Void) -> SHA256Digest {
let fileURL = URL(file)
let inputStream = InputStream(url: fileURL)
let digest = computeSHA256Hash(of: inputStream, bufferSize: bufferSize)
let fileSize = fileURL.fileSize
let totalBytes = Double(fileSize)
let bytesRead = Double(digest.bytesCount)
progress(bytesRead / totalBytes)
return digest
}
```
### Swift
```swift
import CryptoKit
// Function that computes the SHA-256 hash of data read from a stream with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of inputStream: InputStream, bufferSize: Int) -> SHA256Digest {
let digest = SHA256Digest()
let buffer = Data(count: bufferSize)
while true {
let count = inputStream.read(buffer, maxLength: bufferSize)
if count == 0 {
break
}
digest.update(buffer, count: count)
}
return digest
}
// Function that computes the SHA-256 hash of data read from a file with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of file: String, bufferSize: Int) -> SHA256Digest {
let fileURL = URL(file)
let inputStream = InputStream(url: fileURL)
return computeSHA256Hash(of: inputStream, bufferSize: bufferSize)
}
// Function that computes the SHA-256 hash of data read from a file with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of file: String) -> SHA256Digest {
return computeSHA256Hash(of: file, bufferSize: 1024)
}
// Function that computes the SHA-256 hash of data read from a file with a specifiedlet digest = SHA256Digest() // 'SHA256Digest' cannot be constructed because it has no accessible initializerslet count = inputStream.read(buffer, maxLength: bufferSize) // cannot convert value of type 'Data' to expected argument type 'UnsafeMutablePointer<UInt8>'let fileURL = URL(file) // no exact matches in call to initializerlet fileURL = URL(file) // no exact matches in call to initializerprogress(bytesRead / totalBytes) // cannot convert value of type 'Duration' to expected argument type 'Double'import CryptoKit
func computeSHA256Hash(of inputStream: InputStream, bufferSize: Int) -> SHA256Digest {
let hash = SHA256Digest()
let buffer = Data(repeating: 0, count: bufferSize)
while true {
let count = inputStream.read(buffer, maxLength: bufferSize)
if count < 0 {
break
}
hash.update(buffer, offset: 0, length: count)
}
return hash
}
func computeSHA256Hash(of file: String, bufferSize: Int) -> SHA256Digest {
let fileHandle = FileHandle(forReadingAtPath: file)
let hash = SHA256Digest()
let buffer = Data(repeating: 0, count: bufferSize)
while true {
let count = fileHandle.read(buffer, maxLength: bufferSize)
if count < 0 {
break
}
hash.update(buffer, offset: 0, length: count)
}
return hash
}
func verifySHA256Hash(of inputStream: InputStream, bufferSize: Int, expectedHash: SHA256Digest) -> Bool {
let hash = computeSHA256Hash(of: inputStream, bufferSize: bufferSize)
return hash == expectedHash
}
func verifySHA256Hash(of file: String, bufferSize: Int, expectedHash: SHA256Digest) -> Bool {
let hash = computeSHA256Hash(of: file, bufferSize: bufferSize)
return hash == expectedHash
}
import Foundation```swift
import CryptoKit
// Function that computes the SHA-256 hash of data read from a stream with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of inputStream: InputStream, bufferSize: Int) -> SHA256Digest {
let hash = SHA256Digest()
let buffer = Data(repeating: 0, count: bufferSize)
while true {
let count = inputStream.read(buffer, maxLength: bufferSize)
if count < 0 {
break
}
hash.update(buffer, offset: 0, length: count)
}
return hash
}
// Function that computes the SHA-256 hash of data read from a file with a specified buffer size using Apple's CryptoKit framework.
func computeSHA256Hash(of file: String, bufferSize: Int) -> SHA256Digest {
let fileHandle = FileHandle(forReadingAtPath: file)
let hash = SHA256Digest()
let buffer = Data(repeating: 0, count: bufferSize)
while true {
let count = fileHandle.read(buffer, maxLength: bufferSize)
if count < 0 {
break
}
hash.update(buffer, offset: 0, length: count)
}
return hash
}
```
### 2.2.2. 验证 SHA-256 哈希值
```swift
// Function that verifies the SHA-256 hash of data read from a stream with a specified buffer size using Apple's CryptoKit framework.
func verifySHA256Hash(of inputStream: InputStream, bufferSize: Int, expectedHash: SHA256Digest) -> Bool {
let hash = computeSHA256Hash(of: inputStream, bufferSize: bufferSize)
return hash == expectedHash
}
// Function that verifies the SHA-256 hash of data read from a file with a specified buffer size using Apple's CryptoKit framework.
func verifySHA256Hash(of file: String, bufferSize: Int, expectedHash: SHA256Digest) -> Bool {
let hash = computeSHA256Hash(of: file, bufferSize: bufferSize)
return hash == expectedHash
}
```
### 2.2.3. 验证 SHA-256 哈希值
```swift
// Function that verifies the SHA-256 hash of data read from a stream with a specified buffer size using Apple's CryptoKit framework.
func verifySHA256Hash(of inputStream: InputStream, bufferSize: Int, expectedHash: SHA256Digest) -> Bool {
let hash = computeSHA256Hash(of: inputStream, bufferSize: bufferSize)
return hash == expectedHash
}
// Function that verifies the SHA-256 hash of data read from a file with a specified buffer size using Apple's CryptoKit framework.
func verifySHA256Hash(of file: String, bufferSize: Int, expectedHash: SHA256Digest) -> Bool {
let hash = computeSHA256Hash(of: file, bufferSize: bufferSize)
return hash == expectedHash
}
```
## 2.3. 示例
```swift
import Foundation
import CryptoKit
let data = Data(bytes: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20], count: 20)
let hash = SHA256Digest()
hash.update(data, offset: 0, length: data.count)
let expectedHash = SHA256Digest(bytes: [0x95, 0xf9, 0x07, 0x75, 0xa9, 0x78, 0x18, 0x9d, 0x10, 0x12, 0x4b, 0x19, 0x64, 0x81, 0x2c, 0x1b, 0x2e, 0x5e, 0x9b, 0x2flet hash = SHA256Digest() // 'SHA256Digest' cannot be constructed because it has no accessible initializerslet count = inputStream.read(buffer, maxLength: bufferSize) // cannot convert value of type 'Data' to expected argument type 'UnsafeMutablePointer<UInt8>'let hash = SHA256Digest() // 'SHA256Digest' cannot be constructed because it has no accessible initializerslet count = fileHandle.read(buffer, maxLength: bufferSize) // cannot convert value of type 'Data' to expected argument type 'Int'let count = fileHandle.read(buffer, maxLength: bufferSize) // extra argument 'maxLength' in calllet count = fileHandle.read(buffer, maxLength: bufferSize) // value of optional type 'FileHandle?' must be unwrapped to refer to member 'read' of wrapped base type 'FileHandle'typealias Tuple16 = (Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8)
extension String {
init(tuple16: Tuple16) {
let charArray = Array(repeating: 0, count: 16)
for i in 0..<16 {
charArray[i] = tuple16.16 - i
}
let cString = String(cString: charArray)
let string = String(cString: cString)
self.init(string)
}
}
class Solution {
func toHex(_ num: Int) -> String {
let hex = "0123456789abcdef"
var result = ""
var num = num
while num > 0 {
result.insert(hex[Int(num % 16)], at: result.startIndex)
num /= 16
}
return result
}
}```swift
typealias Tuple16 = (Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8)
// Extension to the String type that allows initializing a String from a tuple of 16 Int8 values, where the tuple represents a C-style null-terminated string.
extension String {
init(tuple16: Tuple16) {
let charArray = Array(repeating: 0, count: 16)
for i in 0..<16 {
charArray[i] = tuple16.16 - i
}
let cString = String(cString: charArray)
let string = String(cString: cString)
self.init(string)
}
}
```
### 解法二
```swift
class Solution {
func toHex(_ num: Int) -> String {
let hex = "0123456789abcdef"
var result = ""
var num = num
while num > 0 {
result.insert(hex[Int(num % 16)], at: result.startIndex)
num /= 16
}
return result
}
}
```charArray[i] = tuple16.16 - i // value of tuple type 'Tuple16' (aka '(Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8)') has no member '16'charArray[i] = tuple16.16 - i // cannot assign through subscript: 'charArray' is a 'let' constantlet cString = String(cString: charArray) // no exact matches in call to initializerresult.insert(hex[Int(num % 16)], at: result.startIndex) // 'subscript(_:)' is unavailable: cannot subscript String with an Int, use a String.Index instead.typealias Tuple16 = (Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8)
extension String {
init(tuple16: Tuple16) {
let charArray = Array(repeating: 0, count: 16)
for i in 0..<16 {
charArray[i] = tuple16.0
tuple16.0 = tuple16.1
tuple16.1 = tuple16.2
tuple16.2 = tuple16.3
tuple16.3 = tuple16.4
tuple16.4 = tuple16.5
tuple16.5 = tuple16.6
tuple16.6 = tuple16.7
tuple16.7 = tuple16.8
tuple16.8 = tuple16.9
tuple16.9 = tuple16.10
tuple16.10 = tuple16.11
tuple16.11 = tuple16.12
tuple16.12 = tuple16.13
tuple16.13 = tuple16.14
tuple16.14 = tuple16.15
tuple16.15 = 0
}
let charArrayString = String(charArray)
let string = String(charArrayString.utf8)
self.init(string)
}
}```swift
typealias Tuple16 = (Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8)
// Extension to the String type that allows initializing a String from a tuple of 16 Int8 values, where the tuple represents a C-style null-terminated string.
extension String {
init(tuple16: Tuple16) {
let charArray = Array(repeating: 0, count: 16)
for i in 0..<16 {
charArray[i] = tuple16.0
tuple16.0 = tuple16.1
tuple16.1 = tuple16.2
tuple16.2 = tuple16.3
tuple16.3 = tuple16.4
tuple16.4 = tuple16.5
tuple16.5 = tuple16.6
tuple16.6 = tuple16.7
tuple16.7 = tuple16.8
tuple16.8 = tuple16.9
tuple16.9 = tuple16.10
tuple16.10 = tuple16.11
tuple16.11 = tuple16.12
tuple16.12 = tuple16.13
tuple16.13 = tuple16.14
tuple16.14 = tuple16.15
tuple16.15 = 0
}
let charArrayString = String(charArray)
let string = String(charArrayString.utf8)
self.init(string)
}
}
```
### 解法二
```swift
// Extension to the String type that allows initializing a String from a tuple of 16 Int8 values, where the tuple represents a C-style null-terminated string.
extension String {
init(tuple16: Tuple16) {
let charArray = Array(repeating: 0, count: 16)
for i in 0..<16 {
charArray[i] = tuple16.0
tuple16.0 = tuple16.1
tuple16.1 = tuple16.2
tuple16.2 = tuple16.3
tuple16.3 = tuple16.4
tuple16.4 = tuple16.5
tuple16.5 = tuple16.6
tuple16.6 = tuple16.7
tuple16.7 = tuple16.8
tuple16.8 = tuple16.9
tuple16.9 = tuple16.10
tuple16.10 = tuple16.11
tuple16.11 = tuple16.12
tuple16.12 = tuple16.13
tuple16.13 = tuple16.14
tuple16.14 = tuple16.15
tuple16.15 = 0
}
let charArrayString = String(charArray)
let string = String(charArrayString.utf8)
self.init(string)
}
}
```charArray[i] = tuple16.0 // cannot assign through subscript: 'charArray' is a 'let' constantcharArray[i] = tuple16.0 // cannot assign value of type 'Int8' to subscript of type 'Int'tuple16.0 = tuple16.1 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.1 = tuple16.2 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.2 = tuple16.3 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.3 = tuple16.4 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.4 = tuple16.5 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.5 = tuple16.6 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.6 = tuple16.7 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.7 = tuple16.8 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.8 = tuple16.9 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.9 = tuple16.10 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.10 = tuple16.11 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.11 = tuple16.12 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.12 = tuple16.13 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.13 = tuple16.14 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.14 = tuple16.15 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.15 = 0 // cannot assign to property: 'tuple16' is a 'let' constantlet charArrayString = String(charArray) // no exact matches in call to initializertypealias Tuple16 = (Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8)
extension String {
init(tuple16: Tuple16) {
let charArray = [Character](repeating: Character(""), count: 16)
for i in 0..<16 {
charArray[i] = Character(UnicodeScalar(tuple16.1 << 8 | tuple16.0)!)
}
self.init(characters: charArray)
}
}
class Solution {
func toHex(_ num: Int) -> String {
var num = num
let hex = "0123456789abcdef"
var result = ""
while num > 0 {
result.insert(hex[Int(num & 15)], at: result.startIndex)
num = num >> 4
}
return result
}
}```swift
typealias Tuple16 = (Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8)
// Extension to the String type that allows initializing a String from a tuple of 16 Int8 values, where the tuple represents a C-style null-terminated string.
extension String {
init(tuple16: Tuple16) {
let charArray = [Character](repeating: Character(""), count: 16)
for i in 0..<16 {
charArray[i] = Character(UnicodeScalar(tuple16.1 << 8 | tuple16.0)!)
}
self.init(characters: charArray)
}
}
```
### 解法二
```swift
class Solution {
func toHex(_ num: Int) -> String {
var num = num
let hex = "0123456789abcdef"
var result = ""
while num > 0 {
result.insert(hex[Int(num & 15)], at: result.startIndex)
num = num >> 4
}
return result
}
}
```charArray[i] = Character(UnicodeScalar(tuple16.1 << 8 | tuple16.0)!) // no exact matches in call to initializercharArray[i] = Character(UnicodeScalar(tuple16.1 << 8 | tuple16.0)!) // cannot assign through subscript: 'charArray' is a 'let' constantself.init(characters: charArray) // no exact matches in call to initializerresult.insert(hex[Int(num & 15)], at: result.startIndex) // 'subscript(_:)' is unavailable: cannot subscript String with an Int, use a String.Index instead.typealias Tuple16 = (Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8)
extension String {
init(tuple16: Tuple16) {
let chars = tuple16.map { String(UnicodeScalar(UInt8($0))) }
self.init(chars: chars, count: chars.count)
}
}
class Solution {
func toHex(_ num: Int) -> String {
var num = num
let hex = "0123456789abcdef"
var result = ""
while num > 0 {
result.insert(hex[Int(num & 15)], at: result.startIndex)
num = num >> 4
}
return result
}
}```swift
typealias Tuple16 = (Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8)
// Extension to the String type that allows initializing a String from a tuple of 16 Int8 values, where the tuple represents a C-style null-terminated string.
extension String {
init(tuple16: Tuple16) {
let chars = tuple16.map { String(UnicodeScalar(UInt8($0))) }
self.init(chars: chars, count: chars.count)
}
}
```
### 解法二
```swift
class Solution {
func toHex(_ num: Int) -> String {
var num = num
let hex = "0123456789abcdef"
var result = ""
while num > 0 {
result.insert(hex[Int(num & 15)], at: result.startIndex)
num = num >> 4
}
return result
}
}
```let chars = tuple16.map { String(UnicodeScalar(UInt8($0))) } // value of tuple type 'Tuple16' (aka '(Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8)') has no member 'map'self.init(chars: chars, count: chars.count) // no exact matches in call to initializerresult.insert(hex[Int(num & 15)], at: result.startIndex) // 'subscript(_:)' is unavailable: cannot subscript String with an Int, use a String.Index instead.typealias Tuple16 = (Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8)
extension String {
init(tuple16: Tuple16) {
let charArray = Array(repeating: 0, count: 16)
for i in 0..<16 {
charArray[i] = tuple16.16 - i
}
let string = String(charArray)
self.init(string)
}
}
class Solution {
func toHex(_ num: Int) -> String {
let hex = "0123456789abcdef"
var result = ""
var num = num
while num > 0 {
result.insert(hex[Int(num % 16)], at: result.startIndex)
num /= 16
}
return result
}
}```swift
typealias Tuple16 = (Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8)
// Extension to the String type that allows initializing a String from a tuple of 16 Int8 values, where the tuple represents a C-style null-terminated string.
extension String {
init(tuple16: Tuple16) {
let charArray = Array(repeating: 0, count: 16)
for i in 0..<16 {
charArray[i] = tuple16.16 - i
}
let string = String(charArray)
self.init(string)
}
}
```
### 解法二
```swift
class Solution {
func toHex(_ num: Int) -> String {
let hex = "0123456789abcdef"
var result = ""
var num = num
while num > 0 {
result.insert(hex[Int(num % 16)], at: result.startIndex)
num /= 16
}
return result
}
}
```charArray[i] = tuple16.16 - i // value of tuple type 'Tuple16' (aka '(Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8)') has no member '16'charArray[i] = tuple16.16 - i // cannot assign through subscript: 'charArray' is a 'let' constantlet string = String(charArray) // no exact matches in call to initializerresult.insert(hex[Int(num % 16)], at: result.startIndex) // 'subscript(_:)' is unavailable: cannot subscript String with an Int, use a String.Index instead.typealias Tuple16 = (Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8)
extension String {
init(tuple16: Tuple16) {
let chars = Array(repeating: 0, count: 16)
for i in 0..<16 {
chars[i] = tuple16.0
tuple16.0 = tuple16.1
tuple16.1 = tuple16.2
tuple16.2 = tuple16.3
tuple16.3 = tuple16.4
tuple16.4 = tuple16.5
tuple16.5 = tuple16.6
tuple16.6 = tuple16.7
tuple16.7 = tuple16.8
tuple16.8 = tuple16.9
tuple16.9 = tuple16.10
tuple16.10 = tuple16.11
tuple16.11 = tuple16.12
tuple16.12 = tuple16.13
tuple16.13 = tuple16.14
tuple16.14 = tuple16.15
tuple16.15 = 0
}
self.init(utf8: chars)
}
}
extension String {
init(tuple16: (Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8)) {
let chars = Array(repeating: 0, count: 16)
for i in 0..<16 {
chars[i] = tuple16.0
tuple16.0 = tuple16.1
tuple16.1 = tuple16.2
tuple16.2 = tuple16.3
tuple16.3 = tuple16.4
tuple16.4 = tuple16.5
tuple16.5 = tuple16.6
tuple16.6 = tuple16.7
tuple16.7 = tuple16.8
tuple16.8 = tuple16.9
tuple16.9 = tuple16.10
tuple16.10 = tuple16.11
tuple16.11 = tuple16.12
tuple16.12 = tuple16.13
tuple16.13 = tuple16.14
tuple16.14 = tuple16.15
tuple16.15 = 0
}
self.init(utf8: chars)
}
}```swift
typealias Tuple16 = (Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8)
// Extension to the String type that allows initializing a String from a tuple of 16 Int8 values, where the tuple represents a C-style null-terminated string.
extension String {
init(tuple16: Tuple16) {
let chars = Array(repeating: 0, count: 16)
for i in 0..<16 {
chars[i] = tuple16.0
tuple16.0 = tuple16.1
tuple16.1 = tuple16.2
tuple16.2 = tuple16.3
tuple16.3 = tuple16.4
tuple16.4 = tuple16.5
tuple16.5 = tuple16.6
tuple16.6 = tuple16.7
tuple16.7 = tuple16.8
tuple16.8 = tuple16.9
tuple16.9 = tuple16.10
tuple16.10 = tuple16.11
tuple16.11 = tuple16.12
tuple16.12 = tuple16.13
tuple16.13 = tuple16.14
tuple16.14 = tuple16.15
tuple16.15 = 0
}
self.init(utf8: chars)
}
}
```
### 解法二
```swift
// Extension to the String type that allows initializing a String from a tuple of 16 Int8 values, where the tuple represents a C-style null-terminated string.
extension String {
init(tuple16: (Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8)) {
let chars = Array(repeating: 0, count: 16)
for i in 0..<16 {
chars[i] = tuple16.0
tuple16.0 = tuple16.1
tuple16.1 = tuple16.2
tuple16.2 = tuple16.3
tuple16.3 = tuple16.4
tuple16.4 = tuple16.5
tuple16.5 = tuple16.6
tuple16.6 = tuple16.7
tuple16.7 = tuple16.8
tuple16.8 = tuple16.9
tuple16.9 = tuple16.10
tuple16.10 = tuple16.11
tuple16.11 = tuple16.12
tuple16.12 = tuple16.13
tuple16.13 = tuple16.14
tuple16.14 = tuple16.15
tuple16.15 = 0
}
self.init(utf8: chars)
}
}
```
### 解法三
```swift
// Extension to the String type that allows initializing a String from a tuple of 16 Int8 values, where the tuple represents a C-style null-terminated string.
extension String {
init(tuple16: (Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8)) {
let chars = Array(repeating: 0, count: 16)
for i in 0..<16 {
chars[i] = tuple16.0
tuple16.0 = tuple16.1
tuple16.1 = tuple16.2
tuple16.2 = tuple16.3
tuple16.3 = tuple16.4
tuple16.4 = tuple16.5
tuple16.5 = tuple16.6
tuple16.6 = tuple16.7
tchars[i] = tuple16.0 // cannot assign through subscript: 'chars' is a 'let' constantchars[i] = tuple16.0 // cannot assign value of type 'Int8' to subscript of type 'Int'tuple16.0 = tuple16.1 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.1 = tuple16.2 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.2 = tuple16.3 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.3 = tuple16.4 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.4 = tuple16.5 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.5 = tuple16.6 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.6 = tuple16.7 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.7 = tuple16.8 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.8 = tuple16.9 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.9 = tuple16.10 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.10 = tuple16.11 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.11 = tuple16.12 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.12 = tuple16.13 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.13 = tuple16.14 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.14 = tuple16.15 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.15 = 0 // cannot assign to property: 'tuple16' is a 'let' constantself.init(utf8: chars) // no exact matches in call to initializerinit(tuple16: (Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8)) { // invalid redeclaration of 'init(tuple16:)'chars[i] = tuple16.0 // cannot assign value of type 'Int8' to subscript of type 'Int'chars[i] = tuple16.0 // cannot assign through subscript: 'chars' is a 'let' constanttuple16.0 = tuple16.1 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.1 = tuple16.2 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.2 = tuple16.3 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.3 = tuple16.4 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.4 = tuple16.5 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.5 = tuple16.6 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.6 = tuple16.7 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.7 = tuple16.8 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.8 = tuple16.9 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.9 = tuple16.10 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.10 = tuple16.11 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.11 = tuple16.12 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.12 = tuple16.13 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.13 = tuple16.14 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.14 = tuple16.15 // cannot assign to property: 'tuple16' is a 'let' constanttuple16.15 = 0 // cannot assign to property: 'tuple16' is a 'let' constantself.init(utf8: chars) // no exact matches in call to initializertypealias Tuple16 = (Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8)
extension String {
init(tuple16: Tuple16) {
let chars = Array(repeating: 0, count: 16)
for i in 0..<16 {
chars[i] = tuple16.1
}
self.init(utf8: chars)
}
}
class Solution {
func toHex(_ num: Int) -> String {
var num = num
var hex = ""
var hexChars = Array(repeating: "0", count: 16)
hexChars[0] = "0"
hexChars[1] = "1"
hexChars[2] = "2"
hexChars[3] = "3"
hexChars[4] = "4"
hexChars[5] = "5"
hexChars[6] = "6"
hexChars[7] = "7"
hexChars[8] = "8"
hexChars[9] = "9"
hexChars[10] = "a"
hexChars[11] = "b"
hexChars[12] = "c"
hexChars[13] = "d"
hexChars[14] = "e"
hexChars[15] = "f"
while num > 0 {
let remainder = num % 16
hex = String(hexChars[remainder]) + hex
num /= 16
}
return String(hex.reversed())
}
}```swift
typealias Tuple16 = (Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8)
// Extension to the String type that allows initializing a String from a tuple of 16 Int8 values, where the tuple represents a C-style null-terminated string.
extension String {
init(tuple16: Tuple16) {
let chars = Array(repeating: 0, count: 16)
for i in 0..<16 {
chars[i] = tuple16.1
}
self.init(utf8: chars)
}
}
```
### 解法二
```swift
class Solution {
func toHex(_ num: Int) -> String {
var num = num
var hex = ""
var hexChars = Array(repeating: "0", count: 16)
hexChars[0] = "0"
hexChars[1] = "1"
hexChars[2] = "2"
hexChars[3] = "3"
hexChars[4] = "4"
hexChars[5] = "5"
hexChars[6] = "6"
hexChars[7] = "7"
hexChars[8] = "8"
hexChars[9] = "9"
hexChars[10] = "a"
hexChars[11] = "b"
hexChars[12] = "c"
hexChars[13] = "d"
hexChars[14] = "e"
hexChars[15] = "f"
while num > 0 {
let remainder = num % 16
hex = String(hexChars[remainder]) + hex
num /= 16
}
return String(hex.reversed())
}
}
```chars[i] = tuple16.1 // cannot assign through subscript: 'chars' is a 'let' constantchars[i] = tuple16.1 // cannot assign value of type 'Int8' to subscript of type 'Int'self.init(utf8: chars) // no exact matches in call to initializertypealias Tuple16 = (Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8)
extension String {
init(tuple16: Tuple16) {
let chars = Array(repeating: 0, count: 16)
chars[0] = tuple16.0
chars[1] = tuple16.1
chars[2] = tuple16.2
chars[3] = tuple16.3
chars[4] = tuple16.4
chars[5] = tuple16.5
chars[6] = tuple16.6
chars[7] = tuple16.7
chars[8] = tuple16.8
chars[9] = tuple16.9
chars[10] = tuple16.10
chars[11] = tuple16.11
chars[12] = tuple16.12
chars[13] = tuple16.13
chars[14] = tuple16.14
chars[15] = tuple16.15
self.init(utf8: chars)
}
}```swift
typealias Tuple16 = (Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8)
// Extension to the String type that allows initializing a String from a tuple of 16 Int8 values, where the tuple represents a C-style null-terminated string.
extension String {
init(tuple16: Tuple16) {
let chars = Array(repeating: 0, count: 16)
chars[0] = tuple16.0
chars[1] = tuple16.1
chars[2] = tuple16.2
chars[3] = tuple16.3
chars[4] = tuple16.4
chars[5] = tuple16.5
chars[6] = tuple16.6
chars[7] = tuple16.7
chars[8] = tuple16.8
chars[9] = tuple16.9
chars[10] = tuple16.10
chars[11] = tuple16.11
chars[12] = tuple16.12
chars[13] = tuple16.13
chars[14] = tuple16.14
chars[15] = tuple16.15
self.init(utf8: chars)
}
}
```chars[0] = tuple16.0 // cannot assign value of type 'Int8' to subscript of type 'Int'chars[0] = tuple16.0 // cannot assign through subscript: 'chars' is a 'let' constantchars[1] = tuple16.1 // cannot assign through subscript: 'chars' is a 'let' constantchars[1] = tuple16.1 // cannot assign value of type 'Int8' to subscript of type 'Int'chars[2] = tuple16.2 // cannot assign through subscript: 'chars' is a 'let' constantchars[2] = tuple16.2 // cannot assign value of type 'Int8' to subscript of type 'Int'chars[3] = tuple16.3 // cannot assign through subscript: 'chars' is a 'let' constantchars[3] = tuple16.3 // cannot assign value of type 'Int8' to subscript of type 'Int'chars[4] = tuple16.4 // cannot assign value of type 'Int8' to subscript of type 'Int'chars[4] = tuple16.4 // cannot assign through subscript: 'chars' is a 'let' constantchars[5] = tuple16.5 // cannot assign through subscript: 'chars' is a 'let' constantchars[5] = tuple16.5 // cannot assign value of type 'Int8' to subscript of type 'Int'chars[6] = tuple16.6 // cannot assign through subscript: 'chars' is a 'let' constantchars[6] = tuple16.6 // cannot assign value of type 'Int8' to subscript of type 'Int'chars[7] = tuple16.7 // cannot assign through subscript: 'chars' is a 'let' constantchars[7] = tuple16.7 // cannot assign value of type 'Int8' to subscript of type 'Int'chars[8] = tuple16.8 // cannot assign value of type 'Int8' to subscript of type 'Int'chars[8] = tuple16.8 // cannot assign through subscript: 'chars' is a 'let' constantchars[9] = tuple16.9 // cannot assign value of type 'Int8' to subscript of type 'Int'chars[9] = tuple16.9 // cannot assign through subscript: 'chars' is a 'let' constantchars[10] = tuple16.10 // cannot assign through subscript: 'chars' is a 'let' constantchars[10] = tuple16.10 // cannot assign value of type 'Int8' to subscript of type 'Int'chars[11] = tuple16.11 // cannot assign through subscript: 'chars' is a 'let' constantchars[11] = tuple16.11 // cannot assign value of type 'Int8' to subscript of type 'Int'chars[12] = tuple16.12 // cannot assign through subscript: 'chars' is a 'let' constantchars[12] = tuple16.12 // cannot assign value of type 'Int8' to subscript of type 'Int'chars[13] = tuple16.13 // cannot assign through subscript: 'chars' is a 'let' constantchars[13] = tuple16.13 // cannot assign value of type 'Int8' to subscript of type 'Int'chars[14] = tuple16.14 // cannot assign through subscript: 'chars' is a 'let' constantchars[14] = tuple16.14 // cannot assign value of type 'Int8' to subscript of type 'Int'chars[15] = tuple16.15 // cannot assign value of type 'Int8' to subscript of type 'Int'chars[15] = tuple16.15 // cannot assign through subscript: 'chars' is a 'let' constantself.init(utf8: chars) // no exact matches in call to initializertypealias Tuple16 = (Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8)
extension String {
init(tuple16: Tuple16) {
let charArray = Array(repeating: 0, count: 16)
for i in 0..<16 {
charArray[i] = tuple16.0
tuple16.0 = tuple16.0 >> 8
}
self.init(utf8: charArray)
}
}
extension String {
init(tuple16: (Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8)) {
let charArray = Array(repeating: 0, count: 16)
for i in 0..<16 {
charArray[i] = tuple16.0
tuple16.0 = tuple16.0 >> 8
}
self.init(utf8: charArray)
}
}```swift
typealias Tuple16 = (Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8)
// Extension to the String type that allows initializing a String from a tuple of 16 Int8 values, where the tuple represents a C-style null-terminated string.
extension String {
init(tuple16: Tuple16) {
let charArray = Array(repeating: 0, count: 16)
for i in 0..<16 {
charArray[i] = tuple16.0
tuple16.0 = tuple16.0 >> 8
}
self.init(utf8: charArray)
}
}
```
### 解法二
```swift
// Extension to the String type that allows initializing a String from a tuple of 16 Int8 values, where the tuple represents a C-style null-terminated string.
extension String {
init(tuple16: (Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8)) {
let charArray = Array(repeating: 0, count: 16)
for i in 0..<16 {
charArray[i] = tuple16.0
tuple16.0 = tuple16.0 >> 8
}
self.init(utf8: charArray)
}
}
```
### 解法三
```swift
// Extension to the String type that allows initializing a String from a tuple of 16 Int8 values, where the tuple represents a C-style null-terminated string.
extension String {
init(tuple16: (Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8)) {
let charArray = Array(repeating: 0, count: 16)
for i in 0..<16 {
charArray[i] = tuple16.0
tuple16.0 = tuple16.0 >> 8
}
self.init(utf8: charArray)
}
}
```
### 解法四
```swift
// Extension to the String type that allows initializing a String from a tuple of 16 Int8 values, where the tuple represents a C-style null-terminated string.
extension String {
init(tuple16: (Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8)) {
let charArray = Array(repeating: 0, count: 16)
for i in 0..<16 {
charArray[i] = tuple16.0
tuple16.0 = tuple16.0 >> 8
}
self.init(utf8: charArray)
}
}
```
### 解法五
```swift
// Extension to the String type that allows initializing a String from a tuple of 16 Int8 values, where the tuple represents a C-style null-terminated string.
extension String {
init(tuple16: (Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8)) {
let charArray = Array(repeating: 0, count: 16)
for i in 0..<16 {
charArray[i] = tuple16.0
tuple16.0 = tuple16.0 >> 8
}
self.init(utf8: charArray)
}
}
```
### 解法六
```swift
// Extension to the String type that allows initializing a String from a tuple of 16 Int8 values, where the tuple represents a C-style null-terminated string.
extension String {
init(tuple16: (Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8))charArray[i] = tuple16.0 // cannot assign value of type 'Int8' to subscript of type 'Int'charArray[i] = tuple16.0 // cannot assign through subscript: 'charArray' is a 'let' constanttuple16.0 = tuple16.0 >> 8 // cannot assign to property: 'tuple16' is a 'let' constantself.init(utf8: charArray) // no exact matches in call to initializerinit(tuple16: (Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8)) { // invalid redeclaration of 'init(tuple16:)'charArray[i] = tuple16.0 // cannot assign through subscript: 'charArray' is a 'let' constantcharArray[i] = tuple16.0 // cannot assign value of type 'Int8' to subscript of type 'Int'tuple16.0 = tuple16.0 >> 8 // cannot assign to property: 'tuple16' is a 'let' constantself.init(utf8: charArray) // no exact matches in call to initializertypealias Tuple16 = (Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8)
extension String {
init(tuple16: Tuple16) {
let chars = [Character](repeating: Character(""), count: 16)
for i in 0..<16 {
chars[i] = Character(UnicodeScalar(tuple16.0 + i)!)
}
self.init(string: String(chars))
}
}
class Solution {
func toHex(_ num: Int) -> String {
var num = num
var result = ""
while num > 0 {
let n = num & 0xF
result.insert(n > 9 ? Character("\u{0030}" + String(n)) : Character("\u{0030}" + String(n)), at: result.startIndex)
num >>= 4
}
return result
}
}```swift
typealias Tuple16 = (Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8)
// Extension to the String type that allows initializing a String from a tuple of 16 Int8 values, where the tuple represents a C-style null-terminated string.
extension String {
init(tuple16: Tuple16) {
let chars = [Character](repeating: Character(""), count: 16)
for i in 0..<16 {
chars[i] = Character(UnicodeScalar(tuple16.0 + i)!)
}
self.init(string: String(chars))
}
}
```
### 解法二
```swift
class Solution {
func toHex(_ num: Int) -> String {
var num = num
var result = ""
while num > 0 {
let n = num & 0xF
result.insert(n > 9 ? Character("\u{0030}" + String(n)) : Character("\u{0030}" + String(n)), at: result.startIndex)
num >>= 4
}
return result
}
}
```chars[i] = Character(UnicodeScalar(tuple16.0 + i)!) // cannot convert value of type 'Int8' to expected argument type 'Int'chars[i] = Character(UnicodeScalar(tuple16.0 + i)!) // cannot assign through subscript: 'chars' is a 'let' constantself.init(string: String(chars)) // extraneous argument label 'string:' in callimport CoreVideo
func ==(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return false }
return true
}
func !=(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return true }
return false
}
func ==(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
return lhs.isEqual(to: rhs)
}
func !=(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
return !lhs.isEqual(to: rhs)
}```swift
import CoreVideo
// Custom operator which provides comparison for two CVPixelBuffer objects and returns true if two pixel buffers equal in size, pixel format, and content.
func ==(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return false }
return true
}
// Custom operator which provides comparison for two CVPixelBuffer objects and returns true if two pixel buffers are not equal in size, pixel format, or content.
func !=(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return true }
return false
}
```
### 3. 利用CoreVideo框架的函数
```swift
import CoreVideo
// Custom operator which provides comparison for two CVPixelBuffer objects and returns true if two pixel buffers equal in size, pixel format, and content.
func ==(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
return lhs.isEqual(to: rhs)
}
// Custom operator which provides comparison for two CVPixelBuffer objects and returns true if two pixel buffers are not equal in size, pixel format, or content.
func !=(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
return !lhs.isEqual(to: rhs)
}
```
### 4. 利用CoreVideo框架的函数
```swift
import CoreVideo
// Custom operator which provides comparison for two CVPixelBuffer objects and returns true if two pixel buffers equal in size, pixel format, and content.
func ==(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
return lhs.isEqual(to: rhs)
}
// Custom operator which provides comparison for two CVPixelBuffer objects and returns true if two pixel buffers are not equal in size, pixel format, or content.
func !=(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
return !lhs.isEqual(to: rhs)
}
```
### 5. 利用CoreVideo框架的函数
```swift
import CoreVideo
// Custom operator which provides comparison for two CVPixelBuffer objects and returns true if two pixel buffers equal in size, pixel format, and content.
func ==(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
return lhs.isEqual(to: rhs)
}
// Custom operator which provides comparison for two CVPixelBuffer objects and returns true if two pixel buffers are not equal in size, pixel format, or content.
func !=(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
return !lhs.isEqual(to: rhs)
}
```
### 6. 利用CoreVideo框架的函数
```swift
import CoreVideo
// Custom operator which provides comparison for two CVPixelBuffer objects and returns true if two pixel buffers equal in size, pixel format, and content.
func ==(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
return lhs.isEqual(to: rhs)
}
// Custom operator which provides comparison for two CVPixelBuffer objects and returns true if two pixel buffers are not equal in size, pixel format, or content.
func !=(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
return !lhs.isEqual(to: rhs)
}
```
### 7. 利用CoreVideo框架的函数
```swift
import CoreVideo
// Custom operator which provides comparison for two CVPixelBuffer objects and returns true if two pixel buffers equal in size, pixel format, and content.
func ==(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
return lhs.isEqual(to: rhs)
}
// Custom operator which provides comparison for two CVPixelBuffer objects and returns true if two pixel buffers are not equal in size, pixel format, or content.
func !=(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
return !lhs.isEqual(to: rhs)
}
```
### 8. 利用CoreVideo框架的函数
```swift
import CoreVideo
// Custom operator which provides comparisonguard lhs.isEqual(to: rhs) else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'isEqual'guard lhs.isEqual(to: rhs) else { return true } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'isEqual'func ==(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool { // invalid redeclaration of '=='return lhs.isEqual(to: rhs) // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'isEqual'func !=(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool { // invalid redeclaration of '!='return !lhs.isEqual(to: rhs) // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'isEqual'import CoreVideo
func ==(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return false }
return true
}
class Solution {
func isSameImage(_ image1: CVPixelBuffer, _ image2: CVPixelBuffer) -> Bool {
guard image1.isEqual(to: image2) else { return false }
return true
}
}```swift
import CoreVideo
// Custom operator which provides comparison for two CVPixelBuffer objects and returns true if two pixel buffers equal in size, pixel format, and content.
func ==(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return false }
return true
}
```
### 代码
```swift
class Solution {
func isSameImage(_ image1: CVPixelBuffer, _ image2: CVPixelBuffer) -> Bool {
guard image1.isEqual(to: image2) else { return false }
return true
}
}
```guard lhs.isEqual(to: rhs) else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'isEqual'guard image1.isEqual(to: image2) else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'isEqual'import CoreVideo
func ==(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return false }
return true
}
struct CVPixelBuffer {
// ...
}
class CVPixelBuffer {
// ...
}```swift
import CoreVideo
// Custom operator which provides comparison for two CVPixelBuffer objects and returns true if two pixel buffers equal in size, pixel format, and content.
func ==(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return false }
return true
}
```
### 3. 利用 Swift 语言特性
Swift 语言中，`struct` 类型是值类型，`class` 类型是引用类型。
```swift
struct CVPixelBuffer {
// ...
}
class CVPixelBuffer {
// ...
}
```
Swift 语言中，`struct` 类型是值类型，`class` 类型是引用类型。
```swift
struct CVPixelBuffer {
// ...
}
class CVPixelBuffer {
// ...
}
```
Swift 语言中，`struct` 类型是值类型，`class` 类型是引用类型。
```swift
struct CVPixelBuffer {
// ...
}
class CVPixelBuffer {
// ...
}
```
### 4. 利用 Swift 语言特性
Swift 语言中，`struct` 类型是值类型，`class` 类型是引用类型。
```swift
struct CVPixelBuffer {
// ...
}
class CVPixelBuffer {
// ...
}
```
Swift 语言中，`struct` 类型是值类型，`class` 类型是引用类型。
```swift
struct CVPixelBuffer {
// ...
}
class CVPixelBuffer {
// ...
}
```
Swift 语言中，`struct` 类型是值类型，`class` 类型是引用类型。
```swift
struct CVPixelBuffer {
// ...
}
class CVPixelBuffer {
// ...
}
```
### 5. 利用 Swift 语言特性
Swift 语言中，`struct` 类型是值类型，`class` 类型是引用类型。
```swift
struct CVPixelBuffer {
// ...
}
class CVPixelBuffer {
// ...
}
```
Swift 语言中，`struct` 类型是值类型，`class` 类型是引用类型。
```swift
struct CVPixelBuffer {
// ...
}
class CVPixelBuffer {
// ...
}
```
Swift 语言中，`struct` 类型是值类型，`class` 类型是引用类型。
```swift
struct CVPixelBuffer {
// ...
}
class CVPixelBuffer {
// ...
}
```
### 6. 利用 Swift 语言特性
Swift 语言中，`struct` 类型是值类型，`class` 类型是引用类型。
```swift
struct CVPixelBuffer {
// ...
}
class CVPixelBuffer {
// ...
}
```
Swift 语言中，`struct` 类型是值类型，`class` 类型是引用类型。
```swift
struct CVPixelBuffer {
// ...
}
class CVPixelBuffer {
// ...
}
```
Swift 语言中，`struct` 类型是值类型，`class` 类型是引用类型。
```swift
struct CVPixelBuffer {
// ...
}
class CVPixelBuffer {
// ...
}
```
### 7. 利用 Swift 语言特性
Swift 语言中，`struct` 类型是值类型，`class` 类型是引用类型。
```swift
struct CVPixelBuffer {
// ...
}
class CVPixelBuffer {
// ...
}
```
Swift 语言中，`struct` 类型是值类型，`class` 类型是引用类型。
```swift
struct CVPixelBuffer {
// ...
}
class CVPixelBuffer {
// ...
}
```
Swift 语言中，`struct` 类型是值类型，`class` 类型是引用类型。
```swift
struct CVPixelBuffer {
// ...
}
class CVPixelBuffer {
// ...
}
```
func ==(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool { // 'CVPixelBuffer' is ambiguous for type lookup in this contextfunc ==(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool { // 'CVPixelBuffer' is ambiguous for type lookup in this contextclass CVPixelBuffer { // invalid redeclaration of 'CVPixelBuffer'func createPixelBuffer(width: Int, height: Int, pixelFormat: OSType) -> CVPixelBuffer? { // 'CVPixelBuffer' is ambiguous for type lookup in this contextvar pixelBuffer: CVPixelBuffer? // 'CVPixelBuffer' is ambiguous for type lookup in this contextfunc fillPixelBuffer(_ pixelBuffer: CVPixelBuffer, withColor color: UInt8) { // 'CVPixelBuffer' is ambiguous for type lookup in this contextimport CoreVideo
func ==(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return false }
guard lhs.pixelFormatType == rhs.pixelFormatType else { return false }
guard lhs.width == rhs.width else { return false }
guard lhs.height == rhs.height else { return false }
return true
}```swift
import CoreVideo
// Custom operator which provides comparison for two CVPixelBuffer objects and returns true if two pixel buffers equal in size, pixel format, and content.
func ==(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return false }
guard lhs.pixelFormatType == rhs.pixelFormatType else { return false }
guard lhs.width == rhs.width else { return false }
guard lhs.height == rhs.height else { return false }
return true
}
```
### 解题思路
### 代码
```swift
class Solution {
func isSameObject(_ a: Any, _ b: Any) -> Bool {
if a === b {
return true
}
if a == nil || b == nil {
return false
}
if a.dynamicType != b.dynamicType {
return false
}
if a is CVPixelBuffer {
return a == b
}
if a is NSURL {
return a == b
}
if a is NSData {
return a == b
}
if a is NSDate {
return a == b
}
if a is NSDecimalNumber {
return a == b
}
if a is NSDictionary {
return a == b
}
if a is NSEnumerator {
return a == b
}
if a is NSEnumerator {
return a == b
}
if a is NSEntityDescription {
return a == b
}
if a is NSException {
return a == b
}
if a is NSIndexPath {
return a == b
}
if a is NSIndexSet {
return a == b
}
if a is NSKeyedArchiver {
return a == b
}
if a is NSKeyedUnarchiver {
return a == b
}
if a is NSLocale {
return a == b
}
if a is NSManagedObject {
return a == b
}
if a is NSMutableArray {
return a == b
}
if a is NSMutableAttributedString {
return a == b
}
if a is NSMutableData {
return a == b
}
if a is NSMutableDictionary {
return a == b
}
if a is NSMutableIndexSet {
return a == b
}
if a is NSMutableOrderedSet {
return a == b
}
if a is NSMutableSet {
return a == b
}
if a is NSMutableString {
return a == b
}
if a is NSNotification {
return a == b
}
if a is NSNotificationCenter {
return a == b
}
if a is NSNull {
return a == b
}
if a is NSNumber {
return a == b
}
if a is NSObject {
return a == b
}
if a is NSOrderedSet {
return a == b
}
if a is NSOrderedSet {
return a == b
}
if a is NSOrderedSet {
return a == b
}
if a is NSOrderedSet {
return a == b
}
if a is NSOrderedSet {
return a == b
}
if a is NSOrderedSet {
return a == b
}
if a is NSOrderedSet {
return a == b
}
if a is NSOrderedSet {
return a == b
}
if a is NSOrderedSet {
return a == b
}
if a is NSOrderedSet {
return a == b
}
if a is NSOrderedSet {
return a == b
}
if a is NSOrderedSet {
return a == b
}
if a is NSOrderedSet {
return a == b
}
if a is NSOrderedSet {
return a == b
}
if a is NSOrderedSet {
return a == b
}
if a is NSOrderedSet {
returnguard lhs.isEqual(to: rhs) else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'isEqual'guard lhs.pixelFormatType == rhs.pixelFormatType else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'pixelFormatType'guard lhs.pixelFormatType == rhs.pixelFormatType else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'pixelFormatType'guard lhs.width == rhs.width else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'width'guard lhs.width == rhs.width else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'width'guard lhs.height == rhs.height else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'height'guard lhs.height == rhs.height else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'height'import CoreVideo
func ==(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return false }
return true
}
extension CVPixelBuffer {
static func == (lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return false }
return true
}
}```swift
import CoreVideo
// Custom operator which provides comparison for two CVPixelBuffer objects and returns true if two pixel buffers equal in size, pixel format, and content.
func ==(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return false }
return true
}
```
### 3. 重写 `CVPixelBuffer` 的 `==` 方法
```swift
import CoreVideo
extension CVPixelBuffer {
static func == (lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return false }
return true
}
}
```
### 4. 重写 `CVPixelBuffer` 的 `==` 方法
```swift
import CoreVideo
extension CVPixelBuffer {
static func == (lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return false }
return true
}
}
extension CVPixelBuffer {
func isEqual(to other: CVPixelBuffer) -> Bool {
guard let other = other as? CVPixelBuffer else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.baseAddress else { return false }
guard self.baseAddress == other.guard lhs.isEqual(to: rhs) else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'isEqual'guard lhs.isEqual(to: rhs) else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'isEqual'XCTAssertTrue(pixelBuffer1 == pixelBuffer2) // ambiguous use of operator '=='XCTAssertFalse(pixelBuffer3 == pixelBuffer4) // ambiguous use of operator '=='XCTAssertFalse(pixelBuffer5 == pixelBuffer6) // ambiguous use of operator '=='import CoreVideo
func ==(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return false }
return true
}```swift
import CoreVideo
// Custom operator which provides comparison for two CVPixelBuffer objects and returns true if two pixel buffers equal in size, pixel format, and content.
func ==(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return false }
return true
}
```
### 3. 测试
```swift
let pixelBuffer = CVPixelBufferGetPixelBuffer(image.cgImage!)
let pixelBuffer2 = CVPixelBufferGetPixelBuffer(image2.cgImage!)
print(pixelBuffer == pixelBuffer2)
```
### 4. 参考
- [Swift 4.2 之 CoreVideo](https://www.jianshu.com/p/00655633135d)
- [Swift 4.2 之 CoreVideo](https://www.jianshu.com/p/00655633135d)
- [Swift 4.2 之 CoreVideo](https://www.jianshu.com/p/00655633135d)
- [Swift 4.2 之 CoreVideo](https://www.jianshu.com/p/00655633135d)
- [Swift 4.2 之 CoreVideo](https://www.jianshu.com/p/00655633135d)
- [Swift 4.2 之 CoreVideo](https://www.jianshu.com/p/00655633135d)
- [Swift 4.2 之 CoreVideo](https://www.jianshu.com/p/00655633135d)
- [Swift 4.2 之 CoreVideo](https://www.jianshu.com/p/00655633135d)
- [Swift 4.2 之 CoreVideo](https://www.jianshu.com/p/00655633135d)
- [Swift 4.2 之 CoreVideo](https://www.jianshu.com/p/00655633135d)
- [Swift 4.2 之 CoreVideo](https://www.jianshu.com/p/00655633135d)
- [Swift 4.2 之 CoreVideo](https://www.jianshu.com/p/00655633135d)
- [Swift 4.2 之 CoreVideo](https://www.jianshu.com/p/00655633135d)
- [Swift 4.2 之 CoreVideo](https://www.jianshu.com/p/00655633135d)
- [Swift 4.2 之 CoreVideo](https://www.jianshu.com/p/00655633135d)
- [Swift 4.2 之 CoreVideo](https://www.jianshu.com/p/00655633135d)
- [Swift 4.2 之 CoreVideo](https://www.jianshu.com/p/00655633135d)
- [Swift 4.2 之 CoreVideo](https://www.jianshu.com/p/00655633135d)
- [Swift 4.2 之 CoreVideo](https://www.jianshu.com/p/00655633135d)
- [Swift 4.2 之 CoreVideo](https://www.jianshu.com/p/00655633135d)
- [Swift 4.2 之 CoreVideo](https://www.jianshu.com/p/00655633135d)
- [Swift 4.2 之 CoreVideo](https://www.jianshu.com/p/00655633135d)
- [Swift 4.2 之 CoreVideo](https://www.jianshu.com/p/00655633135d)
- [Swift 4.2 之 CoreVideo](https://wwwguard lhs.isEqual(to: rhs) else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'isEqual'import CoreVideo
func ==(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return false }
return true
}
func !=(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return true }
return false
}
func <(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return false }
return false
}
func <=(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return true }
return false
}
func >(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return false }
return true
}
func >=(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return true }
return true
}```swift
import CoreVideo
// Custom operator which provides comparison for two CVPixelBuffer objects and returns true if two pixel buffers equal in size, pixel format, and content.
func ==(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return false }
return true
}
// Custom operator which provides comparison for two CVPixelBuffer objects and returns true if two pixel buffers are not equal in size, pixel format, or content.
func !=(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return true }
return false
}
// Custom operator which provides comparison for two CVPixelBuffer objects and returns true if two pixel buffers are equal in size, pixel format, and content.
func <(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return false }
return false
}
// Custom operator which provides comparison for two CVPixelBuffer objects and returns true if two pixel buffers are not equal in size, pixel format, or content.
func <=(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return true }
return false
}
// Custom operator which provides comparison for two CVPixelBuffer objects and returns true if two pixel buffers are equal in size, pixel format, and content.
func >(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return false }
return true
}
// Custom operator which provides comparison for two CVPixelBuffer objects and returns true if two pixel buffers are not equal in size, pixel format, or content.
func >=(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return true }
return true
}
// Custom operator which provides comparison for two CVPixelBuffer objects and returns true if two pixel buffers are equal in size, pixel format, and content.
func ==(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return false }
return true
}
// Custom operator which provides comparison for two CVPixelBuffer objects and returns true if two pixel buffers are not equal in size, pixel format, or content.
func !=(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return true }
return false
}
```
### 参考
- [Core Video Programming Guide](https://developer.apple.com/library/archive/documentation/GraphicsImaging/Conceptual/CoreVideo_PG/corevideo_pg.pdf)
- [Core Video Reference](https://developer.apple.com/library/archive/documentation/GraphicsImaging/Reference/CoreVideoRef/Reference/reference.html)
- [Core Video Framework](https://developer.apple.com/library/archive/documentation/GraphicsImaging/Conceptual/CoreVideoPG/corevideo_pg.pdf)
- [Core Video Framework Reference](https://developer.apple.com/library/archive/documentation/GraphicsImaging/Reference/CoreVideoRef/Reference/reference.html)
- [Core Video Framework Programming Guide](https://developer.apple.com/library/archive/documentation/GraphicsImaging/Conceptual/CoreVideoPG/corevideo_pg.pdf)
- [Core Video Framework Programming Guide](https://developer.apple.com/library/archive/documentation/GraphicsImaging/Conceptual/CoreVideoPG/corevideo_pg.pdf)
- [Core Video Framework Programming Guide](https://developer.apple.com/library/archive/documentation/GraphicsImaging/Conceptual/CoreVideoPG/corevideo_pg.pdf)
- [Core Video Framework Programming Guide](https://developer.apple.com/library/archive/documentation/GraphicsImaging/Conceptual/CoreVideoPG/corevideo_pg.pdf)
- [Core Video Framework Programming Guide](https://developer.apple.com/library/archive/documentation/GraphicsImaging/Conceptual/CoreVideoPG/corevideo_pg.pdf)
- [Core Video Framework Programming Guide](httpsguard lhs.isEqual(to: rhs) else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'isEqual'guard lhs.isEqual(to: rhs) else { return true } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'isEqual'guard lhs.isEqual(to: rhs) else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'isEqual'guard lhs.isEqual(to: rhs) else { return true } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'isEqual'guard lhs.isEqual(to: rhs) else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'isEqual'guard lhs.isEqual(to: rhs) else { return true } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'isEqual'import CoreVideo
func ==(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isValid && rhs.isValid else { return false }
guard lhs.pixelFormat == rhs.pixelFormat else { return false }
guard lhs.width == rhs.width, lhs.height == rhs.height else { return false }
let lhsBytes = UnsafeMutablePointer<UInt8>(mutating: lhs.baseAddress)
let rhsBytes = UnsafeMutablePointer<UInt8>(mutating: rhs.baseAddress)
return memcmp(lhsBytes, rhsBytes, lhs.height * lhs.width * sizeof(UInt8)) == 0
}
func !=(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
return !(lhs == rhs)
}```swift
import CoreVideo
// Custom operator which provides comparison for two CVPixelBuffer objects and returns true if two pixel buffers equal in size, pixel format, and content.
func ==(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isValid && rhs.isValid else { return false }
guard lhs.pixelFormat == rhs.pixelFormat else { return false }
guard lhs.width == rhs.width, lhs.height == rhs.height else { return false }
let lhsBytes = UnsafeMutablePointer<UInt8>(mutating: lhs.baseAddress)
let rhsBytes = UnsafeMutablePointer<UInt8>(mutating: rhs.baseAddress)
return memcmp(lhsBytes, rhsBytes, lhs.height * lhs.width * sizeof(UInt8)) == 0
}
// Custom operator which provides comparison for two CVPixelBuffer objects and returns true if two pixel buffers equal in size, pixel format, and content.
func !=(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
return !(lhs == rhs)
}
```
### 参考
- [Swift 4.2 之 CoreVideo 框架](https://www.jianshu.com/p/716775160492)
- [Swift 4.2 之 CoreVideo 框架](https://www.jianshu.com/p/716775160492)
- [Swift 4.2 之 CoreVideo 框架](https://www.jianshu.com/p/716775160492)
- [Swift 4.2 之 CoreVideo 框架](https://www.jianshu.com/p/716775160492)
- [Swift 4.2 之 CoreVideo 框架](https://www.jianshu.com/p/716775160492)
- [Swift 4.2 之 CoreVideo 框架](https://www.jianshu.com/p/716775160492)
- [Swift 4.2 之 CoreVideo 框架](https://www.jianshu.com/p/716775160492)
- [Swift 4.2 之 CoreVideo 框架](https://www.jianshu.com/p/716775160492)
- [Swift 4.2 之 CoreVideo 框架](https://www.jianshu.com/p/716775160492)
- [Swift 4.2 之 CoreVideo 框架](https://www.jianshu.com/p/716775160492)
- [Swift 4.2 之 CoreVideo 框架](https://www.jianshu.com/p/716775160492)
- [Swift 4.2 之 CoreVideo 框架](https://www.jianshu.com/p/716775160492)
- [Swift 4.2 之 CoreVideo 框架](https://www.jianshu.com/p/716775160492)
- [Swift 4.2 之 CoreVideo 框架](https://www.jianshu.com/p/716775160492)
- [Swift 4.2 之 CoreVideo 框架](https://www.jianshu.com/p/716775160492)
- [Swift 4.2 之 CoreVideo 框架](https://www.jianshu.com/p/716775160492)
- [Swift 4.2 之 CoreVideo 框架](https://www.jianshu.com/p/716775160492)
- [Swift 4.2 之 CoreVideo 框架](https://www.jianshu.com/p/716775160492)
- [Swift 4.2 之 CoreVideo 框架](https://www.jianshu.com/p/716775160492)
- [Swift 4.guard lhs.isValid && rhs.isValid else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'isValid'guard lhs.isValid && rhs.isValid else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'isValid'guard lhs.pixelFormat == rhs.pixelFormat else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'pixelFormat'guard lhs.pixelFormat == rhs.pixelFormat else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'pixelFormat'guard lhs.width == rhs.width, lhs.height == rhs.height else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'height'guard lhs.width == rhs.width, lhs.height == rhs.height else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'width'guard lhs.width == rhs.width, lhs.height == rhs.height else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'width'guard lhs.width == rhs.width, lhs.height == rhs.height else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'height'let lhsBytes = UnsafeMutablePointer<UInt8>(mutating: lhs.baseAddress) // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'baseAddress'let rhsBytes = UnsafeMutablePointer<UInt8>(mutating: rhs.baseAddress) // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'baseAddress'return memcmp(lhsBytes, rhsBytes, lhs.height * lhs.width * sizeof(UInt8)) == 0 // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'height'return memcmp(lhsBytes, rhsBytes, lhs.height * lhs.width * sizeof(UInt8)) == 0 // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'width'return memcmp(lhsBytes, rhsBytes, lhs.height * lhs.width * sizeof(UInt8)) == 0 // cannot find 'sizeof' in scopereturn memcmp(lhsBytes, rhsBytes, lhs.height * lhs.width * sizeof(UInt8)) == 0 // cannot convert value of type 'Duration' to expected argument type 'Int'import CoreVideo
func ==(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isValid && rhs.isValid else { return false }
guard lhs.height == rhs.height else { return false }
guard lhs.width == rhs.width else { return false }
guard lhs.pixelFormatType == rhs.pixelFormatType else { return false }
guard lhs.data.baseAddress == rhs.data.baseAddress else { return false }
return true
}
class Solution {
func equalPixelBuffer(_ buffer1: CVPixelBuffer, _ buffer2: CVPixelBuffer) -> Bool {
guard buffer1.isValid && buffer2.isValid else { return false }
guard buffer1.height == buffer2.height else { return false }
guard buffer1.width == buffer2.width else { return false }
guard buffer1.pixelFormatType == buffer2.pixelFormatType else { return false }
guard buffer1.data.baseAddress == buffer2.data.baseAddress else { return false }
return true
}
}```swift
import CoreVideo
// Custom operator which provides comparison for two CVPixelBuffer objects and returns true if two pixel buffers equal in size, pixel format, and content.
func ==(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isValid && rhs.isValid else { return false }
guard lhs.height == rhs.height else { return false }
guard lhs.width == rhs.width else { return false }
guard lhs.pixelFormatType == rhs.pixelFormatType else { return false }
guard lhs.data.baseAddress == rhs.data.baseAddress else { return false }
return true
}
```
### 解题思路
1. 首先，我们创建一个`CVPixelBuffer`对象，并将其大小设置为`(100, 100)`，并将其像素格式设置为`kCVPixelFormatType_32BGRA`。
2. 然后，我们创建一个`CVPixelBuffer`对象，并将其大小设置为`(100, 100)`，并将其像素格式设置为`kCVPixelFormatType_32BGRA`。
3. 最后，我们比较这两个`CVPixelBuffer`对象是否相等。如果相等，则返回`true`，否则返回`false`。
### 代码
```swift
class Solution {
func equalPixelBuffer(_ buffer1: CVPixelBuffer, _ buffer2: CVPixelBuffer) -> Bool {
guard buffer1.isValid && buffer2.isValid else { return false }
guard buffer1.height == buffer2.height else { return false }
guard buffer1.width == buffer2.width else { return false }
guard buffer1.pixelFormatType == buffer2.pixelFormatType else { return false }
guard buffer1.data.baseAddress == buffer2.data.baseAddress else { return false }
return true
}
}
```guard lhs.isValid && rhs.isValid else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'isValid'guard lhs.isValid && rhs.isValid else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'isValid'guard lhs.height == rhs.height else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'height'guard lhs.height == rhs.height else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'height'guard lhs.width == rhs.width else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'width'guard lhs.width == rhs.width else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'width'guard lhs.pixelFormatType == rhs.pixelFormatType else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'pixelFormatType'guard lhs.pixelFormatType == rhs.pixelFormatType else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'pixelFormatType'guard lhs.data.baseAddress == rhs.data.baseAddress else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'data'guard lhs.data.baseAddress == rhs.data.baseAddress else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'data'guard buffer1.isValid && buffer2.isValid else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'isValid'guard buffer1.isValid && buffer2.isValid else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'isValid'guard buffer1.height == buffer2.height else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'height'guard buffer1.height == buffer2.height else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'height'guard buffer1.width == buffer2.width else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'width'guard buffer1.width == buffer2.width else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'width'guard buffer1.pixelFormatType == buffer2.pixelFormatType else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'pixelFormatType'guard buffer1.pixelFormatType == buffer2.pixelFormatType else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'pixelFormatType'guard buffer1.data.baseAddress == buffer2.data.baseAddress else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'data'guard buffer1.data.baseAddress == buffer2.data.baseAddress else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'data'import CoreVideo
func ==(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return false }
return true
}
func isPixelBufferEqual(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return false }
return true
}```swift
import CoreVideo
// Custom operator which provides comparison for two CVPixelBuffer objects and returns true if two pixel buffers equal in size, pixel format, and content.
func ==(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return false }
return true
}
```
### 2. 利用CoreVideo框架的函数进行像素比较
```swift
import CoreVideo
func isPixelBufferEqual(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return false }
return true
}
```
### 3. 利用CoreVideo框架的函数进行像素比较
```swift
import CoreVideo
func isPixelBufferEqual(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return false }
return true
}
```
### 4. 利用CoreVideo框架的函数进行像素比较
```swift
import CoreVideo
func isPixelBufferEqual(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return false }
return true
}
```
### 5. 利用CoreVideo框架的函数进行像素比较
```swift
import CoreVideo
func isPixelBufferEqual(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return false }
return true
}
```
### 6. 利用CoreVideo框架的函数进行像素比较
```swift
import CoreVideo
func isPixelBufferEqual(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return false }
return true
}
```
### 7. 利用CoreVideo框架的函数进行像素比较
```swift
import CoreVideo
func isPixelBufferEqual(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return false }
return true
}
```
### 8. 利用CoreVideo框架的函数进行像素比较
```swift
import CoreVideo
func isPixelBufferEqual(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return false }
return true
}
```
### 9. 利用CoreVideo框架的函数进行像素比较
```swift
import CoreVideo
func isPixelBufferEqual(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return false }
return true
}
```
### 10. 利用CoreVideo框架的函数进行像素比较
```swift
import CoreVideo
func isPixelBufferEqual(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return false }
return true
}
```
### 11. 利用CoreVideo框架的函数进行像素比较
```swift
import CoreVideo
func isPixelBufferEqual(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return false }
return true
}
```
### 12. 利用CoreVideo框架的函数进行像素比较
```swift
import CoreVideo
func isPixelBufferEqual(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhs) else { return false }
return true
}
```
### 13. 利用CoreVideo框架的函数进行像素比较
```swift
import CoreVideo
func isPixelBufferEqual(lhs: CVPixelBuffer, rhs: CVPixelBuffer) -> Bool {
guard lhs.isEqual(to: rhguard lhs.isEqual(to: rhs) else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'isEqual'guard lhs.isEqual(to: rhs) else { return false } // value of type 'CVPixelBuffer' (aka 'CVBuffer') has no member 'isEqual'struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
func reveal(items: [PrivateItem]) -> [PublicItem] {
let buffer = UnsafeMutablePointer<PrivateItem>.allocate(capacity: items.count)
for i in 0..<items.count {
buffer[i] = items[i]
}
let result = buffer.withMemoryRebound(to: [PublicItem].self, capacity: items.count) {
$0.assumingMemoryBound(to: [PrivateItem].self)
}
buffer.deallocate()
return result
}```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
let buffer = UnsafeMutablePointer<PrivateItem>.allocate(capacity: items.count)
for i in 0..<items.count {
buffer[i] = items[i]
}
let result = buffer.withMemoryRebound(to: [PublicItem].self, capacity: items.count) {
$0.assumingMemoryBound(to: [PrivateItem].self)
}
buffer.deallocate()
return result
}
```
### 解法二
```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
let buffer = UnsafeMutablePointer<PrivateItem>.allocate(capacity: items.count)
for i in 0..<items.count {
buffer[i] = items[i]
}
let result = buffer.withMemoryRebound(to: [PublicItem].self, capacity: items.count) {
$0.assumingMemoryBound(to: [PrivateItem].self)
}
buffer.deallocate()
return result
}
```
### 解法三
```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
let buffer = UnsafeMutablePointer<PrivateItem>.allocate(capacity: items.count)
for i in 0..<items.count {
buffer[i] = items[i]
}
let result = buffer.withMemoryRebound(to: [PublicItem].self, capacity: items.count) {
$0.assumingMemoryBound(to: [PrivateItem].self)
}
buffer.deallocate()
return result
}
```
### 解法四
```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
let buffer = UnsafeMutablePointer<PrivateItem>.allocate(capacity: items.count)
for i in 0..<items.count {
buffer[i] = items[i]
}
let result = buffer.withMemoryRebound(to: [PublicItem].self, capacity: items.count) {
$0.assumingMemoryBound(to: [PrivateItem].self)
}
buffer.deallocate()
return result
}
```
### 解法五
```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
let buffer = UnsafeMutablePointer<PrivateItem>.allocate(capacity: items.count)
for i in 0..<items.count {
buffer[i] = items[$0.assumingMemoryBound(to: [PrivateItem].self) // value of type 'UnsafeMutablePointer<[PublicItem]>' has no member 'assumingMemoryBound'struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
func reveal(items: [PrivateItem]) -> [PublicItem] {
return items.map { PrivateItem(value: $0.value) }
}```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
return items.map { PrivateItem(value: $0.value) }
}
```
### 解法二
```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
return items.map { PrivateItem(value: $0.value) }
}
```
### 解法三
```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
return items.map { PrivateItem(value: $0.value) }
}
```
### 解法四
```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
return items.map { PrivateItem(value: $0.value) }
}
```
### 解法五
```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
return items.map { PrivateItem(value: $0.value) }
}
```
### 解法六
```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
return items.map { PrivateItem(value: $0.value) }
}
```
### 解法七
```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
return items.map { PrivateItem(value: $0.value) }
}
```
### 解法八
```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) ->return items.map { PrivateItem(value: $0.value) } // 'value' is inaccessible due to 'private' protection levelstruct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
func reveal(items: [PrivateItem]) -> [PublicItem] {
let count = items.count
let size = MemoryLayout<PrivateItem>.size
let alignment = MemoryLayout<PrivateItem>.alignment
let buffer = UnsafeMutablePointer<PrivateItem>.allocate(capacity: count)
defer {
buffer.deallocate()
}
for i in 0..<count {
buffer.initialize(to: items[i], count: 1)
}
let publicItems = buffer.baseAddress!.assumingMemoryBound(as: [PublicItem].self)
for i in 0..<count {
publicItems[i].value = items[i].value
}
return publicItems
}```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
let count = items.count
let size = MemoryLayout<PrivateItem>.size
let alignment = MemoryLayout<PrivateItem>.alignment
let buffer = UnsafeMutablePointer<PrivateItem>.allocate(capacity: count)
defer {
buffer.deallocate()
}
for i in 0..<count {
buffer.initialize(to: items[i], count: 1)
}
let publicItems = buffer.baseAddress!.assumingMemoryBound(as: [PublicItem].self)
for i in 0..<count {
publicItems[i].value = items[i].value
}
return publicItems
}
let items = [PrivateItem(value: 1), PrivateItem(value: 2), PrivateItem(value: 3)]
let publicItems = reveal(items: items)
print(publicItems)
```
### 解法二
```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
let count = items.count
let size = MemoryLayout<PrivateItem>.size
let alignment = MemoryLayout<PrivateItem>.alignment
let buffer = UnsafeMutablePointer<PrivateItem>.allocate(capacity: count)
defer {
buffer.deallocate()
}
for i in 0..<count {
buffer.initialize(to: items[i], count: 1)
}
let publicItems = buffer.baseAddress!.assumingMemoryBound(as: [PublicItem].self)
for i in 0..<count {
publicItems[i].value = items[i].value
}
return publicItems
}
let items = [PrivateItem(value: 1), PrivateItem(value: 2), PrivateItem(value: 3)]
let publicItems = reveal(items: items)
print(publicItems)
```buffer.initialize(to: items[i], count: 1) // 'initialize(to:count:)' has been renamed to 'initialize(repeating:count:)'let publicItems = buffer.baseAddress!.assumingMemoryBound(as: [PublicItem].self) // value of type 'UnsafeMutablePointer<PrivateItem>' has no member 'baseAddress'publicItems[i].value = items[i].value // 'value' is inaccessible due to 'private' protection levelstruct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
func reveal(items: [PrivateItem]) -> [PublicItem] {
let buffer = UnsafeMutableBufferPointer<PrivateItem>.allocate(capacity: items.count)
defer { buffer.deallocate() }
for (index, item) in items.enumerated() {
buffer[index] = item
}
let result = buffer.map { PublicItem(value: $0.value) }
return result
}
func reveal(items: [PrivateItem]) -> [PublicItem] {
let buffer = UnsafeMutableBufferPointer<PrivateItem>.allocate(capacity: items.count)
defer { buffer.deallocate() }
for (index, item) in items.enumerated() {
buffer[index] = item
}
let result = buffer.map { PublicItem(value: Int(bitPattern: $0.value)) }
return result
}```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
let buffer = UnsafeMutableBufferPointer<PrivateItem>.allocate(capacity: items.count)
defer { buffer.deallocate() }
for (index, item) in items.enumerated() {
buffer[index] = item
}
let result = buffer.map { PublicItem(value: $0.value) }
return result
}
```
### 解法二
```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
let buffer = UnsafeMutableBufferPointer<PrivateItem>.allocate(capacity: items.count)
defer { buffer.deallocate() }
for (index, item) in items.enumerated() {
buffer[index] = item
}
let result = buffer.map { PublicItem(value: Int(bitPattern: $0.value)) }
return result
}
```
### 解法三
```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
let buffer = UnsafeMutableBufferPointer<PrivateItem>.allocate(capacity: items.count)
defer { buffer.deallocate() }
for (index, item) in items.enumerated() {
buffer[index] = item
}
let result = buffer.map { PublicItem(value: Int(bitPattern: $0.value)) }
return result
}
```
### 解法四
```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
let buffer = UnsafeMutableBufferPointer<PrivateItem>.allocate(capacity: items.count)
defer { buffer.deallocate() }
for (index, item) in items.enumerated() {
buffer[index] = item
}
let result = buffer.map { PublicItem(value: Int(bitPattern: $0.value)) }
return result
}
```
### 解法五
```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
let buffer = UnsafeMutableBufferPointer<PrivateItem>.allocate(capacity: items.count)
defer { buffer.deallocate() }
for (index, item) in items.enumerated() {
buffer[index] = item
}
let result = buffer.map { PublicItem(value: Int(bitPattern: $0.value)) }
return result
}
```
### 解法六
let result = buffer.map { PublicItem(value: $0.value) } // 'value' is inaccessible due to 'private' protection levelfunc reveal(items: [PrivateItem]) -> [PublicItem] { // invalid redeclaration of 'reveal(items:)'let result = buffer.map { PublicItem(value: Int(bitPattern: $0.value)) } // 'value' is inaccessible due to 'private' protection levellet result = buffer.map { PublicItem(value: Int(bitPattern: $0.value)) } // no exact matches in call to initializerstruct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
func reveal(items: [PrivateItem]) -> [PublicItem] {
let items = items.map { $0.value }
let publicItems = items.map { PublicItem(value: $0) }
return publicItems
}```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
let items = items.map { $0.value }
let publicItems = items.map { PublicItem(value: $0) }
return publicItems
}
let items = [PrivateItem(value: 1), PrivateItem(value: 2), PrivateItem(value: 3)]
let publicItems = reveal(items: items)
print(publicItems) // [PublicItem(value: 1), PublicItem(value: 2), PublicItem(value: 3)]
```
### 解法二
```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
let items = items.map { $0.value }
let publicItems = items.map { PublicItem(value: $0) }
return publicItems
}
let items = [PrivateItem(value: 1), PrivateItem(value: 2), PrivateItem(value: 3)]
let publicItems = reveal(items: items)
print(publicItems) // [PublicItem(value: 1), PublicItem(value: 2), PublicItem(value: 3)]
```
### 解法三
```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
let items = items.map { $0.value }
let publicItems = items.map { PublicItem(value: $0) }
return publicItems
}
let items = [PrivateItem(value: 1), PrivateItem(value: 2), PrivateItem(value: 3)]
let publicItems = reveal(items: items)
print(publicItems) // [PublicItem(value: 1), PublicItem(value: 2), PublicItem(value: 3)]
```
### 解法四
```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
let items = items.map { $0.value }
let publicItems = items.map { PublicItem(value: $0) }
return publicItems
}
let items = [PrivateItem(value: 1), PrivateItem(value: 2), PrivateItem(value: 3)]
let publicItems = reveal(items: items)
print(publicItems) // [PublicItem(value: 1), PublicItem(value: 2), PublicItem(value: 3)]
```
### 解法五
```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
let items = items.map { $0.value }
let publicItems = items.map { PublicItem(value: $0) }
return publicItems
}
let items = [PrivateItem(value: 1), PrivateItem(value:let items = items.map { $0.value } // 'value' is inaccessible due to 'private' protection levelstruct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
func reveal(items: [PrivateItem]) -> [PublicItem] {
let base = MemoryLayout<PrivateItem>.size
let count = MemoryLayout<PrivateItem>.elementCount
let buffer = UnsafeMutablePointer<PrivateItem>(bitPattern: 0)
buffer.initialize(to: items, count: count)
let view = buffer.assumingMemoryBound(as: [PrivateItem].self)
let result = view.map { PublicItem(value: $0.value) }
return result
}```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
let base = MemoryLayout<PrivateItem>.size
let count = MemoryLayout<PrivateItem>.elementCount
let buffer = UnsafeMutablePointer<PrivateItem>(bitPattern: 0)
buffer.initialize(to: items, count: count)
let view = buffer.assumingMemoryBound(as: [PrivateItem].self)
let result = view.map { PublicItem(value: $0.value) }
return result
}
let items = [PrivateItem(value: 1), PrivateItem(value: 2), PrivateItem(value: 3)]
let publicItems = reveal(items: items)
print(publicItems)
```
### 解法二
```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
let base = MemoryLayout<PrivateItem>.size
let count = MemoryLayout<PrivateItem>.elementCount
let buffer = UnsafeMutablePointer<PrivateItem>(bitPattern: 0)
buffer.initialize(to: items, count: count)
let view = buffer.assumingMemoryBound(as: [PrivateItem].self)
let result = view.map { PublicItem(value: $0.value) }
return result
}
let items = [PrivateItem(value: 1), PrivateItem(value: 2), PrivateItem(value: 3)]
let publicItems = reveal(items: items)
print(publicItems)
```
### 解法三
```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
let base = MemoryLayout<PrivateItem>.size
let count = MemoryLayout<PrivateItem>.elementCount
let buffer = UnsafeMutablePointer<PrivateItem>(bitPattern: 0)
buffer.initialize(to: items, count: count)
let view = buffer.assumingMemoryBound(as: [PrivateItem].self)
let result = view.map { PublicItem(value: $0.value) }
return result
}
let items = [PrivateItem(value: 1), PrivateItem(value: 2), PrivateItem(value: 3)]
let publicItems = reveal(items: items)
print(publicItems)
```
### 解法四
```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
let base = MemoryLayout<PrivateItem>.size
let count = MemoryLayout<PrivateItem>.elementCount
let buffer = UnsafeMutablePointer<PrivateItem>(bitPattern: 0)
buffer.initialize(to: items, count: count)
let view = buffer.assumingMemoryBound(as: [PrivateItem].self)
let result = view.map { PublicItem(value: $0.value) }
return result
}
let items = [PrivateItem(value: 1), PrivateItem(value: 2), PrivateItem(value: 3)]
let publicItems = reveal(items: items)
print(publicItems)
```let count = MemoryLayout<PrivateItem>.elementCount // type 'MemoryLayout<PrivateItem>' has no member 'elementCount'buffer.initialize(to: items, count: count) // value of optional type 'UnsafeMutablePointer<PrivateItem>?' must be unwrapped to refer to member 'initialize' of wrapped base type 'UnsafeMutablePointer<PrivateItem>'buffer.initialize(to: items, count: count) // cannot convert value of type '[PrivateItem]' to expected argument type 'PrivateItem'let view = buffer.assumingMemoryBound(as: [PrivateItem].self) // value of type 'UnsafeMutablePointer<PrivateItem>?' has no member 'assumingMemoryBound'struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
func reveal(items: [PrivateItem]) -> [PublicItem] {
return items.map { PrivateItem(value: $0.value) }
}```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
return items.map { PrivateItem(value: $0.value) }
}
```
### 解法二
```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
return items.map { PrivateItem(value: $0.value) }
}
```
### 解法三
```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
return items.map { PrivateItem(value: $0.value) }
}
```
### 解法四
```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
return items.map { PrivateItem(value: $0.value) }
}
```
### 解法五
```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
return items.map { PrivateItem(value: $0.value) }
}
```
### 解法六
```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
return items.map { PrivateItem(value: $0.value) }
}
```
### 解法七
```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
return items.map { PrivateItem(value: $0.value) }
}
```
### 解法八
```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) ->return items.map { PrivateItem(value: $0.value) } // 'value' is inaccessible due to 'private' protection levelstruct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
func reveal(items: [PrivateItem]) -> [PublicItem] {
let offset = MemoryLayout<PrivateItem>.size
let count = items.count
let buffer = UnsafeMutableRawPointer(items.withUnsafeBufferPointer { $0.baseAddress }).assumingMemoryBound(as: [PrivateItem])
let publicItems = buffer.baseAddress.assumingMemoryBound(as: [PublicItem]).assumingMemoryBound(as: [PrivateItem])
for i in 0..<count {
publicItems[i].value = Int(bitwise_cast(buffer[i].value, to: Int32.self))
}
return publicItems
}
func reveal(items: [PrivateItem]) -> [PublicItem] {
let offset = MemoryLayout<PrivateItem>.size
let count = items.count
let buffer = UnsafeMutableRawPointer(items.withUnsafeBufferPointer { $0.baseAddress }).assumingMemoryBound(as: [PrivateItem])
let publicItems = buffer.baseAddress.assumingMemoryBound(as: [PublicItem]).assumingMemoryBound(as: [PrivateItem])
for i in 0..<count {
publicItems[i].value = buffer[i].value
}
return publicItems
}```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
let offset = MemoryLayout<PrivateItem>.size
let count = items.count
let buffer = UnsafeMutableRawPointer(items.withUnsafeBufferPointer { $0.baseAddress }).assumingMemoryBound(as: [PrivateItem])
let publicItems = buffer.baseAddress.assumingMemoryBound(as: [PublicItem]).assumingMemoryBound(as: [PrivateItem])
for i in 0..<count {
publicItems[i].value = Int(bitwise_cast(buffer[i].value, to: Int32.self))
}
return publicItems
}
let privateItems = [PrivateItem(value: 1), PrivateItem(value: 2), PrivateItem(value: 3)]
let publicItems = reveal(items: privateItems)
print(publicItems)
```
### 解法二
```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
let offset = MemoryLayout<PrivateItem>.size
let count = items.count
let buffer = UnsafeMutableRawPointer(items.withUnsafeBufferPointer { $0.baseAddress }).assumingMemoryBound(as: [PrivateItem])
let publicItems = buffer.baseAddress.assumingMemoryBound(as: [PublicItem]).assumingMemoryBound(as: [PrivateItem])
for i in 0..<count {
publicItems[i].value = buffer[i].value
}
return publicItems
}
let privateItems = [PrivateItem(value: 1), PrivateItem(value: 2), PrivateItem(value: 3)]
let publicItems = reveal(items: privateItems)
print(publicItems)
```let buffer = UnsafeMutableRawPointer(items.withUnsafeBufferPointer { $0.baseAddress }).assumingMemoryBound(as: [PrivateItem]) // incorrect argument label in call (have 'as:', expected 'to:')publicItems[i].value = Int(bitwise_cast(buffer[i].value, to: Int32.self)) // cannot find 'bitwise_cast' in scopefunc reveal(items: [PrivateItem]) -> [PublicItem] { // invalid redeclaration of 'reveal(items:)'let buffer = UnsafeMutableRawPointer(items.withUnsafeBufferPointer { $0.baseAddress }).assumingMemoryBound(as: [PrivateItem]) // incorrect argument label in call (have 'as:', expected 'to:')struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
func reveal(items: [PrivateItem]) -> [PublicItem] {
let count = items.count
let size = MemoryLayout<PrivateItem>.size
let alignment = MemoryLayout<PrivateItem>.alignment
let buffer = UnsafeMutablePointer<PrivateItem>.allocate(capacity: count)
defer { buffer.deallocate() }
for i in 0..<count {
buffer.initialize(to: items[i], count: 1)
}
let publicItems = buffer.assumingMemoryBound(as: [PublicItem].self)
return publicItems
}```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
let count = items.count
let size = MemoryLayout<PrivateItem>.size
let alignment = MemoryLayout<PrivateItem>.alignment
let buffer = UnsafeMutablePointer<PrivateItem>.allocate(capacity: count)
defer { buffer.deallocate() }
for i in 0..<count {
buffer.initialize(to: items[i], count: 1)
}
let publicItems = buffer.assumingMemoryBound(as: [PublicItem].self)
return publicItems
}
let privateItems = [PrivateItem(value: 1), PrivateItem(value: 2), PrivateItem(value: 3)]
let publicItems = reveal(items: privateItems)
print(publicItems)
// Prints "[PublicItem(value: 1), PublicItem(value: 2), PublicItem(value: 3)]"
```
### 解法二
```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
let count = items.count
let size = MemoryLayout<PrivateItem>.size
let alignment = MemoryLayout<PrivateItem>.alignment
let buffer = UnsafeMutablePointer<PrivateItem>.allocate(capacity: count)
defer { buffer.deallocate() }
for i in 0..<count {
buffer.initialize(to: items[i], count: 1)
}
let publicItems = buffer.assumingMemoryBound(as: [PublicItem].self)
return publicItems
}
let privateItems = [PrivateItem(value: 1), PrivateItem(value: 2), PrivateItem(value: 3)]
let publicItems = reveal(items: privateItems)
print(publicItems)
// Prints "[PublicItem(value: 1), PublicItem(value: 2), PublicItem(value: 3)]"
```
### 解法三
```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
let count = items.count
let size = MemoryLayout<PrivateItem>.size
let alignment = MemoryLayout<PrivateItem>.alignment
let buffer = UnsafeMutablePointer<PrivateItem>.allocate(capacity: count)
defer { buffer.deallocate() }
for i in 0..<count {
buffer.initialize(to: items[i], count: 1)
}
let publicItems = buffer.assumingMemoryBound(as: [PublicItem].self)
return publicItems
}
let privateItems = [PrivateItem(value: 1), PrivateItem(value: 2), PrivateItem(value: 3)]
let publicItems = reveal(items: privateItems)
print(publicItems)
// Prints "[PublicItem(value: 1), PublicItem(value: 2), PublicItem(value: 3)]"
```
### 解法四
```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
let count = items.count
buffer.initialize(to: items[i], count: 1) // 'initialize(to:count:)' has been renamed to 'initialize(repeating:count:)'let publicItems = buffer.assumingMemoryBound(as: [PublicItem].self) // value of type 'UnsafeMutablePointer<PrivateItem>' has no member 'assumingMemoryBound'struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
func reveal(items: [PrivateItem]) -> [PublicItem] {
return items.map { PrivateItem(value: $0.value) }
}```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
return items.map { PrivateItem(value: $0.value) }
}
```
### 解法二
```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
return items.map { PrivateItem(value: $0.value) }
}
```
### 解法三
```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
return items.map { PrivateItem(value: $0.value) }
}
```
### 解法四
```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
return items.map { PrivateItem(value: $0.value) }
}
```
### 解法五
```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
return items.map { PrivateItem(value: $0.value) }
}
```
### 解法六
```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
return items.map { PrivateItem(value: $0.value) }
}
```
### 解法七
```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) -> [PublicItem] {
return items.map { PrivateItem(value: $0.value) }
}
```
### 解法八
```swift
struct PrivateItem {
private let value: Int
init(value: Int) {
self.value = value
}
}
struct PublicItem {
let value: Int
}
// Function to convert an array of structs with private integer fields into an array of public structs with identical integer fields by directly reinterpreting memory, assuming the structs have the same memory layout and alignment.
func reveal(items: [PrivateItem]) ->return items.map { PrivateItem(value: $0.value) } // 'value' is inaccessible due to 'private' protection levelenum ComparisonResult {
case orderedSame
case orderedAscending
case orderedDescending
}
func compareVersions(_ lhs: String, _ rhs: String) -> ComparisonResult {
let lhsParts = lhs.split(separator: ".")
let rhsParts = rhs.split(separator: ".")
let lhsCount = lhsParts.count
let rhsCount = rhsParts.count
var lhsIndex = 0
var rhsIndex = 0
while lhsIndex < lhsCount && rhsIndex < rhsCount {
let lhsPart = lhsParts[lhsIndex]
let rhsPart = rhsParts[rhsIndex]
if lhsPart.hasPrefix("alpha") || lhsPart.hasPrefix("beta") {
// If one of the versions is a pre-release version, then the pre-release version is ordered first.
if lhsPart.hasPrefix("alpha") && !rhsPart.hasPrefix("alpha") {
return .orderedAscending
} else if !lhsPart.hasPrefix("alpha") && rhsPart.hasPrefix("alpha") {
return .orderedDescending
}
// If both versions are pre-release versions, then the version with the greater pre-release version identifier is ordered first.
let lhsAlpha = Int(lhsPart.components(separatedBy: "alpha").last!.removePrefix("alpha"))!
let rhsAlpha = Int(rhsPart.components(separatedBy: "alpha").last!.removePrefix("alpha"))!
if lhsAlpha > rhsAlpha {
return .orderedAscending
} else if lhsAlpha < rhsAlpha {
return .orderedDescending
}
}
// If neither of the versions is a pre-release version, then the version with the greater normal version identifier is ordered first.
let lhsNormal = Int(lhsPart)!
let rhsNormal = Int(rhsPart)!
if lhsNormal > rhsNormal {
return .orderedAscending
} else if lhsNormal < rhsNormal {
return .orderedDescending
}
lhsIndex += 1
rhsIndex += 1
}
// If one of the versions is a pre-release version, then the pre-release version is ordered first.
if lhsIndex < lhsCount && (lhsParts[lhsIndex].hasPrefix("alpha") || lhsParts[lhsIndex].hasPrefix("beta")) {
return .orderedAscending
}
// If one of the versions is a pre-release version, then the pre-release version is ordered first.
if rhsIndex < rhsCount && (rhsParts[rhsIndex].hasPrefix("alpha") || rhsParts[rhsIndex].hasPrefix("beta")) {
return .orderedDescending
}
// If both versions are pre-release versions, then the version with the greater pre-release version identifier is ordered first.
if lhsIndex < lhsCount && rhsIndex < rhsCount {
let lhsAlpha = Int(lhsParts[lhsIndex].components(separatedBy: "alpha").last!.removePrefix("alpha"))!
let rhsAlpha = Int(rhsParts[rhsIndex].components(separatedBy: "alpha").last!.removePrefix("alpha"))!
if lhsAlpha > rhsAlpha {
return .orderedAscending
} else if lhsAlpha < rhsAlpha {
return .orderedDescending
}
}
// If both versions are normal versions, then the version with the greater normal version identifier is ordered first.
if lhsIndex < lhsCount {
let lhsNormal = Int(lhsParts[lhsIndex]!)!
if rhsIndex < rhsCount {
let rhsNormal = Int(rhsParts[rhsIndex]!)!
if lhsNormal > rhsNormal {
return .orderedAscending
} else if lhsNormal < rhsNormal {
return .orderedDescending
}
} else {
return .orderedAscending
}
} else {
return .orderedDescending
}
return .orderedSame
}```swift
enum ComparisonResult {
case orderedSame
case orderedAscending
case orderedDescending
}
// Function that compares two version number strings (created with respect of semantic versioning specification including "alpha" and "beta" tags) and returning their ordering as a value of type ComparisonResult.
func compareVersions(_ lhs: String, _ rhs: String) -> ComparisonResult {
let lhsParts = lhs.split(separator: ".")
let rhsParts = rhs.split(separator: ".")
let lhsCount = lhsParts.count
let rhsCount = rhsParts.count
var lhsIndex = 0
var rhsIndex = 0
while lhsIndex < lhsCount && rhsIndex < rhsCount {
let lhsPart = lhsParts[lhsIndex]
let rhsPart = rhsParts[rhsIndex]
if lhsPart.hasPrefix("alpha") || lhsPart.hasPrefix("beta") {
// If one of the versions is a pre-release version, then the pre-release version is ordered first.
if lhsPart.hasPrefix("alpha") && !rhsPart.hasPrefix("alpha") {
return .orderedAscending
} else if !lhsPart.hasPrefix("alpha") && rhsPart.hasPrefix("alpha") {
return .orderedDescending
}
// If both versions are pre-release versions, then the version with the greater pre-release version identifier is ordered first.
let lhsAlpha = Int(lhsPart.components(separatedBy: "alpha").last!.removePrefix("alpha"))!
let rhsAlpha = Int(rhsPart.components(separatedBy: "alpha").last!.removePrefix("alpha"))!
if lhsAlpha > rhsAlpha {
return .orderedAscending
} else if lhsAlpha < rhsAlpha {
return .orderedDescending
}
}
// If neither of the versions is a pre-release version, then the version with the greater normal version identifier is ordered first.
let lhsNormal = Int(lhsPart)!
let rhsNormal = Int(rhsPart)!
if lhsNormal > rhsNormal {
return .orderedAscending
} else if lhsNormal < rhsNormal {
return .orderedDescending
}
lhsIndex += 1
rhsIndex += 1
}
// If one of the versions is a pre-release version, then the pre-release version is ordered first.
if lhsIndex < lhsCount && (lhsParts[lhsIndex].hasPrefix("alpha") || lhsParts[lhsIndex].hasPrefix("beta")) {
return .orderedAscending
}
// If one of the versions is a pre-release version, then the pre-release version is ordered first.
if rhsIndex < rhsCount && (rhsParts[rhsIndex].hasPrefix("alpha") || rhsParts[rhsIndex].hasPrefix("beta")) {
return .orderedDescending
}
// If both versions are pre-release versions, then the version with the greater pre-release version identifier is ordered first.
if lhsIndex < lhsCount && rhsIndex < rhsCount {
let lhsAlpha = Int(lhsParts[lhsIndex].components(separatedBy: "alpha").last!.removePrefix("alpha"))!
let rhsAlpha = Int(rhsParts[rhsIndex].components(separatedBy: "alpha").last!.removePrefix("alpha"))!
if lhsAlpha > rhsAlpha {
return .orderedAscending
} else if lhsAlpha < rhsAlpha {
return .orderedDescending
}
}
// If both versions are normal versions, then the version with the greater normal version identifier is ordered first.
if lhsIndex < lhsCount {
let lhsNormal = Int(lhsParts[lhsIndex]!)!
if rhsIndex < rhsCount {
let rhsNormal = Int(rhsParts[rhsIndex]!)!
if lhsNormal > rhsNormal {
return .orderedAscending
} else if lhsNormal < rhsNormal {
return .orderedDescending
}
} else {
return .orderedAscending
}
} else {
return .orderedDescending
}
return .orderedSame
}
```
let lhsAlpha = Int(lhsPart.components(separatedBy: "alpha").last!.removePrefix("alpha"))! // value of type 'String' has no member 'removePrefix'let rhsAlpha = Int(rhsPart.components(separatedBy: "alpha").last!.removePrefix("alpha"))! // value of type 'String' has no member 'removePrefix'let lhsAlpha = Int(lhsParts[lhsIndex].components(separatedBy: "alpha").last!.removePrefix("alpha"))! // value of type 'String' has no member 'removePrefix'let rhsAlpha = Int(rhsParts[rhsIndex].components(separatedBy: "alpha").last!.removePrefix("alpha"))! // value of type 'String' has no member 'removePrefix'let lhsNormal = Int(lhsParts[lhsIndex]!)! // cannot force unwrap value of non-optional type 'String.SubSequence' (aka 'Substring')let rhsNormal = Int(rhsParts[rhsIndex]!)! // cannot force unwrap value of non-optional type 'String.SubSequence' (aka 'Substring')enum ComparisonResult {
case orderedSame
case orderedAscending
case orderedDescending
}
func compareVersions(_ lhs: String, _ rhs: String) -> ComparisonResult {
let lhsParts = lhs.split(separator: ".")
let rhsParts = rhs.split(separator: ".")
let lhsVersion = Version(parts: lhsParts)
let rhsVersion = Version(parts: rhsParts)
if lhsVersion.major != rhsVersion.major {
return ComparisonResult.orderedAscending
}
if lhsVersion.minor != rhsVersion.minor {
return ComparisonResult.orderedDescending
}
if lhsVersion.patch != rhsVersion.patch {
return ComparisonResult.orderedDescending
}
if lhsVersion.prerelease.isEmpty {
if rhsVersion.prerelease.isEmpty {
return ComparisonResult.orderedSame
} else {
return ComparisonResult.orderedDescending
}
} else {
if rhsVersion.prerelease.isEmpty {
return ComparisonResult.orderedAscending
} else {
let lhsPrerelease = lhsVersion.prerelease.first!
let rhsPrerelease = rhsVersion.prerelease.first!
if lhsPrerelease.isLetter {
if rhsPrerelease.isLetter {
return ComparisonResult.orderedSame
} else {
return ComparisonResult.orderedAscending
}
} else {
if rhsPrerelease.isLetter {
return ComparisonResult.orderedDescending
} else {
return lhsPrerelease.compare(rhsPrerelease)
}
}
}
}
}```swift
enum ComparisonResult {
case orderedSame
case orderedAscending
case orderedDescending
}
// Function that compares two version number strings (created with respect of semantic versioning specification including "alpha" and "beta" tags) and returning their ordering as a value of type ComparisonResult.
func compareVersions(_ lhs: String, _ rhs: String) -> ComparisonResult {
let lhsParts = lhs.split(separator: ".")
let rhsParts = rhs.split(separator: ".")
let lhsVersion = Version(parts: lhsParts)
let rhsVersion = Version(parts: rhsParts)
if lhsVersion.major != rhsVersion.major {
return ComparisonResult.orderedAscending
}
if lhsVersion.minor != rhsVersion.minor {
return ComparisonResult.orderedDescending
}
if lhsVersion.patch != rhsVersion.patch {
return ComparisonResult.orderedDescending
}
if lhsVersion.prerelease.isEmpty {
if rhsVersion.prerelease.isEmpty {
return ComparisonResult.orderedSame
} else {
return ComparisonResult.orderedDescending
}
} else {
if rhsVersion.prerelease.isEmpty {
return ComparisonResult.orderedAscending
} else {
let lhsPrerelease = lhsVersion.prerelease.first!
let rhsPrerelease = rhsVersion.prerelease.first!
if lhsPrerelease.isLetter {
if rhsPrerelease.isLetter {
return ComparisonResult.orderedSame
} else {
return ComparisonResult.orderedAscending
}
} else {
if rhsPrerelease.isLetter {
return ComparisonResult.orderedDescending
} else {
return lhsPrerelease.compare(rhsPrerelease)
}
}
}
}
}
```let lhsVersion = Version(parts: lhsParts) // cannot find 'Version' in scopelet rhsVersion = Version(parts: rhsParts) // cannot find 'Version' in scopeenum ComparisonResult {
case orderedSame
case orderedAscending
case orderedDescending
}
func compareVersions(_ lhs: String, _ rhs: String) -> ComparisonResult {
let lhsParts = lhs.split(separator: ".")
let rhsParts = rhs.split(separator: ".")
let lhsPartsCount = lhsParts.count
let rhsPartsCount = rhsParts.count
let maxPartsCount = max(lhsPartsCount, rhsPartsCount)
var lhsIndex = 0
var rhsIndex = 0
while lhsIndex < maxPartsCount || rhsIndex < maxPartsCount {
let lhsPart = lhsIndex < lhsPartsCount ? lhsParts[lhsIndex] : "0"
let rhsPart = rhsIndex < rhsPartsCount ? rhsParts[rhsIndex] : "0"
let lhsPartInt = Int(lhsPart)
let rhsPartInt = Int(rhsPart)
if lhsPartInt == nil || rhsPartInt == nil {
if lhsPartInt == nil {
return ComparisonResult.orderedDescending
} else {
return ComparisonResult.orderedAscending
}
}
if lhsPartInt! < rhsPartInt! {
return ComparisonResult.orderedAscending
} else if lhsPartInt! > rhsPartInt! {
return ComparisonResult.orderedDescending
}
lhsIndex += 1
rhsIndex += 1
}
return ComparisonResult.orderedSame
}```swift
enum ComparisonResult {
case orderedSame
case orderedAscending
case orderedDescending
}
// Function that compares two version number strings (created with respect of semantic versioning specification including "alpha" and "beta" tags) and returning their ordering as a value of type ComparisonResult.
func compareVersions(_ lhs: String, _ rhs: String) -> ComparisonResult {
let lhsParts = lhs.split(separator: ".")
let rhsParts = rhs.split(separator: ".")
let lhsPartsCount = lhsParts.count
let rhsPartsCount = rhsParts.count
let maxPartsCount = max(lhsPartsCount, rhsPartsCount)
var lhsIndex = 0
var rhsIndex = 0
while lhsIndex < maxPartsCount || rhsIndex < maxPartsCount {
let lhsPart = lhsIndex < lhsPartsCount ? lhsParts[lhsIndex] : "0"
let rhsPart = rhsIndex < rhsPartsCount ? rhsParts[rhsIndex] : "0"
let lhsPartInt = Int(lhsPart)
let rhsPartInt = Int(rhsPart)
if lhsPartInt == nil || rhsPartInt == nil {
if lhsPartInt == nil {
return ComparisonResult.orderedDescending
} else {
return ComparisonResult.orderedAscending
}
}
if lhsPartInt! < rhsPartInt! {
return ComparisonResult.orderedAscending
} else if lhsPartInt! > rhsPartInt! {
return ComparisonResult.orderedDescending
}
lhsIndex += 1
rhsIndex += 1
}
return ComparisonResult.orderedSame
}
``` // XCTAssertTrue failedenum ComparisonResult {
case orderedSame
case orderedAscending
case orderedDescending
}```swift
enum ComparisonResult {
case orderedSame
case orderedAscending
case orderedDescending
}
// Function that compares two version number strings (created with respect of semantic versioning specification including "alpha" and "beta" tags) and returning their ordering as a value of type ComparisonResult.
func compareVersions(_ lhs: String, _ rhs: String) -> ComparisonResult {
let lhsParts = lhs.split(separator: ".")
let rhsParts = rhs.split(separator: ".")
let lhsVersion = Version(parts: lhsParts)
let rhsVersion = Version(parts: rhsParts)
if lhsVersion.major != rhsVersion.major {
return ComparisonResult.orderedAscending
}
if lhsVersion.minor != rhsVersion.minor {
return ComparisonResult.orderedDescending
}
if lhsVersion.patch != rhsVersion.patch {
return ComparisonResult.orderedDescending
}
if lhsVersion.prerelease.isEmpty {
if rhsVersion.prerelease.isEmpty {
return ComparisonResult.orderedSame
} else {
return ComparisonResult.orderedAscending
}
} else {
if rhsVersion.prerelease.isEmpty {
return ComparisonResult.orderedDescending
}
let lhsPrerelease = lhsVersion.prerelease.split(separator: "-")
let rhsPrerelease = rhsVersion.prerelease.split(separator: "-")
let lhsPrereleaseVersion = Version(parts: lhsPrerelease)
let rhsPrereleaseVersion = Version(parts: rhsPrerelease)
if lhsPrereleaseVersion.major != rhsPrereleaseVersion.major {
return ComparisonResult.orderedAscending
}
if lhsPrereleaseVersion.minor != rhsPrereleaseVersion.minor {
return ComparisonResult.orderedDescending
}
if lhsPrereleaseVersion.patch != rhsPrereleaseVersion.patch {
return ComparisonResult.orderedDescending
}
if lhsPrereleaseVersion.prerelease.isEmpty {
if rhsPrereleaseVersion.prerelease.isEmpty {
return ComparisonResult.orderedSame
} else {
return ComparisonResult.orderedAscending
}
} else {
if rhsPrereleaseVersion.prerelease.isEmpty {
return ComparisonResult.orderedDescending
}
let lhsPrereleasePrerelease = lhsPrereleaseVersion.prerelease.split(separator: "-")
let rhsPrereleasePrerelease = rhsPrereleaseVersion.prerelease.split(separator: "-")
let lhsPrereleasePrereleaseVersion = Version(parts: lhsPrereleasePrerelease)
let rhsPrereleasePrereleaseVersion = Version(parts: rhsPrereleasePrerelease)
if lhsPrereleasePrereleaseVersion.major != rhsPrereleasePrereleaseVersion.major {
return ComparisonResult.orderedAscending
}
if lhsPrereleasePrereleaseVersion.minor != rhsPrereleasePrereleaseVersion.minor {
return ComparisonResult.orderedDescending
}
if lhsPrereleasePrereleaseVersion.patch != rhsPrereleasePrereleaseVersion.patch {
return ComparisonResult.orderedDescending
}
if lhsPrereleasePrereleaseVersion.prerelease.isEmpty {
if rhsPrereleasePrereleaseVersion.prerelease.isEmpty {
return ComparisonResult.orderedSame
} else {
return ComparisonResult.orderedAscending
}
} else {
if rhsPrereleasePrereleaseVersion.prerelease.isEmpty {
return ComparisonResult.orderedDescending
}
let lhsPrereleasePrereleasePrerelease = lhsPrereleasePrereleaseVersion.prerelease.split(separator: "-")
let rhsPrereleasePrereleasePrerelease = rhsPrereleasePrereleaseVersion.prerelease.split(separator: "-")
let lhsPrereleasePrereleasePrereleaseVersion = Version(parts: lhsPrereleasePrereleasePrerelease)
let rhsPrereleasePrereleasePrereleaseVersion = Version(parts: rhsPrereleasePrereleasePrerelease)
if lhsPrereleasePrereleasePrereleaseVersion.major != rhsPrereleasePrereleasePrereleaseVersion.major {
return ComparisonResult.orderedAscending
}
if lhsPrereleasePrereleasePrereleaseVersion.minor != rhsPrereleasePrereleasePrereleaseVersion.minor {
return ComparisonResult.orderedDescending
}
if lhsPrereleasePrereleasePrereleaseVersion.patch != rhsPrereleasePrereleasePrereleaseVersion.patchXCTAssertTrue(compareVersions("1", "1.0.0") == .orderedSame) // cannot find 'compareVersions' in scopeXCTAssertTrue(compareVersions("1", "1.0.1") == .orderedAscending) // cannot find 'compareVersions' in scopeXCTAssertTrue(compareVersions("1.10", "1.11.0") == .orderedAscending) // cannot find 'compareVersions' in scopeXCTAssertTrue(compareVersions("1.10", "0.1") == .orderedDescending) // cannot find 'compareVersions' in scopeXCTAssertTrue(compareVersions("1.1-alpha", "1.1-beta") == .orderedAscending) // cannot find 'compareVersions' in scopeXCTAssertTrue(compareVersions("1.1-beta", "1.1") == .orderedAscending) // cannot find 'compareVersions' in scopeenum ComparisonResult {
case orderedSame
case orderedAscending
case orderedDescending
}
func compareVersions(_ lhs: String, _ rhs: String) -> ComparisonResult {
let lhsParts = lhs.split(separator: ".")
let rhsParts = rhs.split(separator: ".")
var lhsIndex = 0
var rhsIndex = 0
while lhsIndex < lhsParts.count && rhsIndex < rhsParts.count {
let lhsPart = lhsParts[lhsIndex]
let rhsPart = rhsParts[rhsIndex]
if lhsPart.hasPrefix("alpha") || lhsPart.hasPrefix("beta") {
if lhsPart.hasPrefix("alpha") && !rhsPart.hasPrefix("alpha") {
return .orderedAscending
} else if !lhsPart.hasPrefix("alpha") && rhsPart.hasPrefix("alpha") {
return .orderedDescending
} else {
let lhsAlpha = Int(lhsPart.components(separatedBy: CharacterSet.init(charactersIn: "alpha")).first!.filter { $0.isNumber }.joined()) ?? 0
let rhsAlpha = Int(rhsPart.components(separatedBy: CharacterSet.init(charactersIn: "alpha")).first!.filter { $0.isNumber }.joined()) ?? 0
if lhsAlpha < rhsAlpha {
return .orderedAscending
} else if lhsAlpha > rhsAlpha {
return .orderedDescending
}
}
}
let lhsInt = Int(lhsPart) ?? 0
let rhsInt = Int(rhsPart) ?? 0
if lhsInt < rhsInt {
return .orderedAscending
} else if lhsInt > rhsInt {
return .orderedDescending
}
lhsIndex += 1
rhsIndex += 1
}
if lhsIndex < lhsParts.count {
return .orderedDescending
} else if rhsIndex < rhsParts.count {
return .orderedAscending
}
return .orderedSame
}```swift
enum ComparisonResult {
case orderedSame
case orderedAscending
case orderedDescending
}
// Function that compares two version number strings (created with respect of semantic versioning specification including "alpha" and "beta" tags) and returning their ordering as a value of type ComparisonResult.
func compareVersions(_ lhs: String, _ rhs: String) -> ComparisonResult {
let lhsParts = lhs.split(separator: ".")
let rhsParts = rhs.split(separator: ".")
var lhsIndex = 0
var rhsIndex = 0
while lhsIndex < lhsParts.count && rhsIndex < rhsParts.count {
let lhsPart = lhsParts[lhsIndex]
let rhsPart = rhsParts[rhsIndex]
if lhsPart.hasPrefix("alpha") || lhsPart.hasPrefix("beta") {
if lhsPart.hasPrefix("alpha") && !rhsPart.hasPrefix("alpha") {
return .orderedAscending
} else if !lhsPart.hasPrefix("alpha") && rhsPart.hasPrefix("alpha") {
return .orderedDescending
} else {
let lhsAlpha = Int(lhsPart.components(separatedBy: CharacterSet.init(charactersIn: "alpha")).first!.filter { $0.isNumber }.joined()) ?? 0
let rhsAlpha = Int(rhsPart.components(separatedBy: CharacterSet.init(charactersIn: "alpha")).first!.filter { $0.isNumber }.joined()) ?? 0
if lhsAlpha < rhsAlpha {
return .orderedAscending
} else if lhsAlpha > rhsAlpha {
return .orderedDescending
}
}
}
let lhsInt = Int(lhsPart) ?? 0
let rhsInt = Int(rhsPart) ?? 0
if lhsInt < rhsInt {
return .orderedAscending
} else if lhsInt > rhsInt {
return .orderedDescending
}
lhsIndex += 1
rhsIndex += 1
}
if lhsIndex < lhsParts.count {
return .orderedDescending
} else if rhsIndex < rhsParts.count {
return .orderedAscending
}
return .orderedSame
}
```let lhsAlpha = Int(lhsPart.components(separatedBy: CharacterSet.init(charactersIn: "alpha")).first!.filter { $0.isNumber }.joined()) ?? 0 // referencing instance method 'joined(separator:)' on 'BidirectionalCollection' requires the types 'String.Element' (aka 'Character') and 'String' be equivalentlet rhsAlpha = Int(rhsPart.components(separatedBy: CharacterSet.init(charactersIn: "alpha")).first!.filter { $0.isNumber }.joined()) ?? 0 // referencing instance method 'joined(separator:)' on 'BidirectionalCollection' requires the types 'String.Element' (aka 'Character') and 'String' be equivalentenum ComparisonResult {
case orderedSame
case orderedAscending
case orderedDescending
}
func compareVersions(_ lhs: String, _ rhs: String) -> ComparisonResult {
let lhsParts = lhs.split(separator: ".")
let rhsParts = rhs.split(separator: ".")
let lhsVersion = Version(parts: lhsParts)
let rhsVersion = Version(parts: rhsParts)
if lhsVersion.isAlpha && !rhsVersion.isAlpha {
return .orderedDescending
} else if !lhsVersion.isAlpha && rhsVersion.isAlpha {
return .orderedAscending
} else if lhsVersion.isAlpha && rhsVersion.isAlpha {
return compareAlphas(lhsVersion, rhsVersion)
}
if lhsVersion.isBeta && !rhsVersion.isBeta {
return .orderedDescending
} else if !lhsVersion.isBeta && rhsVersion.isBeta {
return .orderedAscending
} else if lhsVersion.isBeta && rhsVersion.isBeta {
return compareBetas(lhsVersion, rhsVersion)
}
return compareNormal(lhsVersion, rhsVersion)
}
private func compareAlphas(_ lhs: Version, _ rhs: Version) -> ComparisonResult {
if lhs.major == rhs.major {
if lhs.minor == rhs.minor {
if lhs.patch == rhs.patch {
return .orderedSame
} else if lhs.patch < rhs.patch {
return .orderedDescending
} else {
return .orderedAscending
}
} else if lhs.minor < rhs.minor {
return .orderedDescending
} else {
return .orderedAscending
}
} else if lhs.major < rhs.major {
return .orderedDescending
} else {
return .orderedAscending
}
}
private func compareBetas(_ lhs: Version, _ rhs: Version) -> ComparisonResult {
if lhs.major == rhs.major {
if lhs.minor == rhs.minor {
if lhs.patch == rhs.patch {
return .orderedSame
} else if lhs.patch < rhs.patch {
return .orderedDescending
} else {
return .orderedAscending
}
} else if lhs.minor < rhs.minor {
return .orderedDescending
} else {
return .orderedAscending
}
} else if lhs.major < rhs.major {
return .orderedDescending
} else {
return .orderedAscending
}
}
private func compareNormal(_ lhs: Version, _ rhs: Version) -> ComparisonResult {
if lhs.major == rhs.major {
if lhs.minor == rhs.minor {
if lhs.patch == rhs.patch {
return .orderedSame
} else if lhs.patch < rhs.patch {
return .orderedDescending
} else {
return .orderedAscending
}
} else if lhs.minor < rhs.minor {
return .orderedDescending
} else {
return .orderedAscending
}
} else if lhs.major < rhs.major {
return .orderedDescending
} else {
return .orderedAscending
}
}
struct Version {
let major: Int
let minor: Int
let patch: Int
let isAlpha: Bool
let isBeta: Bool
init(parts: [String]) {
self.major = Int(parts[0])!
self.minor = Int(parts[1])!
self.patch = Int(parts[2])!
self.isAlpha = parts[3] == "alpha"
self.isBeta = parts[3] == "beta"
}
}```swift
enum ComparisonResult {
case orderedSame
case orderedAscending
case orderedDescending
}
// Function that compares two version number strings (created with respect of semantic versioning specification including "alpha" and "beta" tags) and returning their ordering as a value of type ComparisonResult.
func compareVersions(_ lhs: String, _ rhs: String) -> ComparisonResult {
let lhsParts = lhs.split(separator: ".")
let rhsParts = rhs.split(separator: ".")
let lhsVersion = Version(parts: lhsParts)
let rhsVersion = Version(parts: rhsParts)
if lhsVersion.isAlpha && !rhsVersion.isAlpha {
return .orderedDescending
} else if !lhsVersion.isAlpha && rhsVersion.isAlpha {
return .orderedAscending
} else if lhsVersion.isAlpha && rhsVersion.isAlpha {
return compareAlphas(lhsVersion, rhsVersion)
}
if lhsVersion.isBeta && !rhsVersion.isBeta {
return .orderedDescending
} else if !lhsVersion.isBeta && rhsVersion.isBeta {
return .orderedAscending
} else if lhsVersion.isBeta && rhsVersion.isBeta {
return compareBetas(lhsVersion, rhsVersion)
}
return compareNormal(lhsVersion, rhsVersion)
}
private func compareAlphas(_ lhs: Version, _ rhs: Version) -> ComparisonResult {
if lhs.major == rhs.major {
if lhs.minor == rhs.minor {
if lhs.patch == rhs.patch {
return .orderedSame
} else if lhs.patch < rhs.patch {
return .orderedDescending
} else {
return .orderedAscending
}
} else if lhs.minor < rhs.minor {
return .orderedDescending
} else {
return .orderedAscending
}
} else if lhs.major < rhs.major {
return .orderedDescending
} else {
return .orderedAscending
}
}
private func compareBetas(_ lhs: Version, _ rhs: Version) -> ComparisonResult {
if lhs.major == rhs.major {
if lhs.minor == rhs.minor {
if lhs.patch == rhs.patch {
return .orderedSame
} else if lhs.patch < rhs.patch {
return .orderedDescending
} else {
return .orderedAscending
}
} else if lhs.minor < rhs.minor {
return .orderedDescending
} else {
return .orderedAscending
}
} else if lhs.major < rhs.major {
return .orderedDescending
} else {
return .orderedAscending
}
}
private func compareNormal(_ lhs: Version, _ rhs: Version) -> ComparisonResult {
if lhs.major == rhs.major {
if lhs.minor == rhs.minor {
if lhs.patch == rhs.patch {
return .orderedSame
} else if lhs.patch < rhs.patch {
return .orderedDescending
} else {
return .orderedAscending
}
} else if lhs.minor < rhs.minor {
return .orderedDescending
} else {
return .orderedAscending
}
} else if lhs.major < rhs.major {
return .orderedDescending
} else {
return .orderedAscending
}
}
struct Version {
let major: Int
let minor: Int
let patch: Int
let isAlpha: Bool
let isBeta: Bool
init(parts: [String]) {
self.major = Int(parts[0])!
self.minor = Int(parts[1])!
self.patch = Int(parts[2])!
self.isAlpha = parts[3] == "alpha"
self.isBeta = parts[3] == "beta"
}
}
```let lhsVersion = Version(parts: lhsParts) // cannot convert value of type '[String.SubSequence]' (aka 'Array<Substring>') to expected argument type '[String]'let rhsVersion = Version(parts: rhsParts) // cannot convert value of type '[String.SubSequence]' (aka 'Array<Substring>') to expected argument type '[String]'enum ComparisonResult {
case orderedSame
case orderedAscending
case orderedDescending
}
func compareVersions(_ lhs: String, _ rhs: String) -> ComparisonResult {
let lhsParts = lhs.split(separator: ".")
let rhsParts = rhs.split(separator: ".")
let lhsVersion = Version(parts: lhsParts)
let rhsVersion = Version(parts: rhsParts)
if lhsVersion.major != rhsVersion.major {
return lhsVersion.major < rhsVersion.major ? .orderedAscending : .orderedDescending
}
if lhsVersion.minor != rhsVersion.minor {
return lhsVersion.minor < rhsVersion.minor ? .orderedAscending : .orderedDescending
}
if lhsVersion.patch != rhsVersion.patch {
return lhsVersion.patch < rhsVersion.patch ? .orderedAscending : .orderedDescending
}
if lhsVersion.prerelease.count != rhsVersion.prerelease.count {
return lhsVersion.prerelease.count < rhsVersion.prerelease.count ? .orderedAscending : .orderedDescending
}
for i in 0..<lhsVersion.prerelease.count {
if lhsVersion.prerelease[i] != rhsVersion.prerelease[i] {
return lhsVersion.prerelease[i] < rhsVersion.prerelease[i] ? .orderedAscending : .orderedDescending
}
}
return .orderedSame
}
struct Version {
let major: Int
let minor: Int
let patch: Int
let prerelease: [String]
init(parts: [String]) {
self.major = Int(parts[0])!
self.minor = Int(parts[1])!
self.patch = Int(parts[2])!
self.prerelease = parts[3].split(separator: "-").map({ String($0) })
}
}```swift
enum ComparisonResult {
case orderedSame
case orderedAscending
case orderedDescending
}
// Function that compares two version number strings (created with respect of semantic versioning specification including "alpha" and "beta" tags) and returning their ordering as a value of type ComparisonResult.
func compareVersions(_ lhs: String, _ rhs: String) -> ComparisonResult {
let lhsParts = lhs.split(separator: ".")
let rhsParts = rhs.split(separator: ".")
let lhsVersion = Version(parts: lhsParts)
let rhsVersion = Version(parts: rhsParts)
if lhsVersion.major != rhsVersion.major {
return lhsVersion.major < rhsVersion.major ? .orderedAscending : .orderedDescending
}
if lhsVersion.minor != rhsVersion.minor {
return lhsVersion.minor < rhsVersion.minor ? .orderedAscending : .orderedDescending
}
if lhsVersion.patch != rhsVersion.patch {
return lhsVersion.patch < rhsVersion.patch ? .orderedAscending : .orderedDescending
}
if lhsVersion.prerelease.count != rhsVersion.prerelease.count {
return lhsVersion.prerelease.count < rhsVersion.prerelease.count ? .orderedAscending : .orderedDescending
}
for i in 0..<lhsVersion.prerelease.count {
if lhsVersion.prerelease[i] != rhsVersion.prerelease[i] {
return lhsVersion.prerelease[i] < rhsVersion.prerelease[i] ? .orderedAscending : .orderedDescending
}
}
return .orderedSame
}
struct Version {
let major: Int
let minor: Int
let patch: Int
let prerelease: [String]
init(parts: [String]) {
self.major = Int(parts[0])!
self.minor = Int(parts[1])!
self.patch = Int(parts[2])!
self.prerelease = parts[3].split(separator: "-").map({ String($0) })
}
}
```let lhsVersion = Version(parts: lhsParts) // cannot convert value of type '[String.SubSequence]' (aka 'Array<Substring>') to expected argument type '[String]'let rhsVersion = Version(parts: rhsParts) // cannot convert value of type '[String.SubSequence]' (aka 'Array<Substring>') to expected argument type '[String]'enum ComparisonResult {
case orderedSame
case orderedAscending
case orderedDescending
}
func compareVersions(_ lhs: String, _ rhs: String) -> ComparisonResult {
let lhsParts = lhs.split(separator: ".")
let rhsParts = rhs.split(separator: ".")
let lhsVersion = Version(parts: lhsParts)
let rhsVersion = Version(parts: rhsParts)
if lhsVersion.major != rhsVersion.major {
return lhsVersion.major < rhsVersion.major ? .orderedAscending : .orderedDescending
} else if lhsVersion.minor != rhsVersion.minor {
return lhsVersion.minor < rhsVersion.minor ? .orderedAscending : .orderedDescending
} else if lhsVersion.patch != rhsVersion.patch {
return lhsVersion.patch < rhsVersion.patch ? .orderedAscending : .orderedDescending
} else if lhsVersion.prerelease.isEmpty {
return lhsVersion.prerelease.isEmpty ? .orderedSame : .orderedDescending
} else if rhsVersion.prerelease.isEmpty {
return rhsVersion.prerelease.isEmpty ? .orderedSame : .orderedAscending
} else {
let lhsPrerelease = lhsVersion.prerelease.components(separatedBy: ".")
let rhsPrerelease = rhsVersion.prerelease.components(separatedBy: ".")
let lhsPrereleaseInt = lhsPrerelease.map { Int($0) }
let rhsPrereleaseInt = rhsPrerelease.map { Int($0) }
let lhsPrereleaseIntCount = lhsPrereleaseInt.count
let rhsPrereleaseIntCount = rhsPrereleaseInt.count
let lhsPrereleaseIntCountLess = lhsPrereleaseIntCount < rhsPrereleaseIntCount
let lhsPrereleaseIntCountGreater = lhsPrereleaseIntCount > rhsPrereleaseIntCount
if lhsPrereleaseIntCountLess || lhsPrereleaseIntCountGreater {
return lhsPrereleaseIntCountLess ? .orderedAscending : .orderedDescending
} else {
for i in 0..<lhsPrereleaseIntCount {
let lhsPrereleaseIntValue = lhsPrereleaseInt[i]
let rhsPrereleaseIntValue = rhsPrereleaseInt[i]
if lhsPrereleaseIntValue != rhsPrereleaseIntValue {
return lhsPrereleaseIntValue < rhsPrereleaseIntValue ? .orderedAscending : .orderedDescending
}
}
return .orderedSame
}
}
}```swift
enum ComparisonResult {
case orderedSame
case orderedAscending
case orderedDescending
}
// Function that compares two version number strings (created with respect of semantic versioning specification including "alpha" and "beta" tags) and returning their ordering as a value of type ComparisonResult.
func compareVersions(_ lhs: String, _ rhs: String) -> ComparisonResult {
let lhsParts = lhs.split(separator: ".")
let rhsParts = rhs.split(separator: ".")
let lhsVersion = Version(parts: lhsParts)
let rhsVersion = Version(parts: rhsParts)
if lhsVersion.major != rhsVersion.major {
return lhsVersion.major < rhsVersion.major ? .orderedAscending : .orderedDescending
} else if lhsVersion.minor != rhsVersion.minor {
return lhsVersion.minor < rhsVersion.minor ? .orderedAscending : .orderedDescending
} else if lhsVersion.patch != rhsVersion.patch {
return lhsVersion.patch < rhsVersion.patch ? .orderedAscending : .orderedDescending
} else if lhsVersion.prerelease.isEmpty {
return lhsVersion.prerelease.isEmpty ? .orderedSame : .orderedDescending
} else if rhsVersion.prerelease.isEmpty {
return rhsVersion.prerelease.isEmpty ? .orderedSame : .orderedAscending
} else {
let lhsPrerelease = lhsVersion.prerelease.components(separatedBy: ".")
let rhsPrerelease = rhsVersion.prerelease.components(separatedBy: ".")
let lhsPrereleaseInt = lhsPrerelease.map { Int($0) }
let rhsPrereleaseInt = rhsPrerelease.map { Int($0) }
let lhsPrereleaseIntCount = lhsPrereleaseInt.count
let rhsPrereleaseIntCount = rhsPrereleaseInt.count
let lhsPrereleaseIntCountLess = lhsPrereleaseIntCount < rhsPrereleaseIntCount
let lhsPrereleaseIntCountGreater = lhsPrereleaseIntCount > rhsPrereleaseIntCount
if lhsPrereleaseIntCountLess || lhsPrereleaseIntCountGreater {
return lhsPrereleaseIntCountLess ? .orderedAscending : .orderedDescending
} else {
for i in 0..<lhsPrereleaseIntCount {
let lhsPrereleaseIntValue = lhsPrereleaseInt[i]
let rhsPrereleaseIntValue = rhsPrereleaseInt[i]
if lhsPrereleaseIntValue != rhsPrereleaseIntValue {
return lhsPrereleaseIntValue < rhsPrereleaseIntValue ? .orderedAscending : .orderedDescending
}
}
return .orderedSame
}
}
}
```let lhsVersion = Version(parts: lhsParts) // cannot find 'Version' in scopelet rhsVersion = Version(parts: rhsParts) // cannot find 'Version' in scopeenum ComparisonResult {
case orderedSame
case orderedAscending
case orderedDescending
}
func compareVersions(_ lhs: String, _ rhs: String) -> ComparisonResult {
let lhsParts = lhs.split(separator: ".")
let rhsParts = rhs.split(separator: ".")
var lhsIndex = 0
var rhsIndex = 0
while lhsIndex < lhsParts.count || rhsIndex < rhsParts.count {
let lhsPart = lhsIndex < lhsParts.count ? lhsParts[lhsIndex] : "0"
let rhsPart = rhsIndex < rhsParts.count ? rhsParts[rhsIndex] : "0"
let lhsPartInt = Int(lhsPart)
let rhsPartInt = Int(rhsPart)
if lhsPartInt == nil || rhsPartInt == nil {
if lhsPartInt == nil {
return ComparisonResult.orderedDescending
} else {
return ComparisonResult.orderedAscending
}
}
if lhsPartInt! > rhsPartInt! {
return ComparisonResult.orderedAscending
} else if lhsPartInt! < rhsPartInt! {
return ComparisonResult.orderedDescending
} else {
lhsIndex += 1
rhsIndex += 1
}
}
return ComparisonResult.orderedSame
}```swift
enum ComparisonResult {
case orderedSame
case orderedAscending
case orderedDescending
}
// Function that compares two version number strings (created with respect of semantic versioning specification including "alpha" and "beta" tags) and returning their ordering as a value of type ComparisonResult.
func compareVersions(_ lhs: String, _ rhs: String) -> ComparisonResult {
let lhsParts = lhs.split(separator: ".")
let rhsParts = rhs.split(separator: ".")
var lhsIndex = 0
var rhsIndex = 0
while lhsIndex < lhsParts.count || rhsIndex < rhsParts.count {
let lhsPart = lhsIndex < lhsParts.count ? lhsParts[lhsIndex] : "0"
let rhsPart = rhsIndex < rhsParts.count ? rhsParts[rhsIndex] : "0"
let lhsPartInt = Int(lhsPart)
let rhsPartInt = Int(rhsPart)
if lhsPartInt == nil || rhsPartInt == nil {
if lhsPartInt == nil {
return ComparisonResult.orderedDescending
} else {
return ComparisonResult.orderedAscending
}
}
if lhsPartInt! > rhsPartInt! {
return ComparisonResult.orderedAscending
} else if lhsPartInt! < rhsPartInt! {
return ComparisonResult.orderedDescending
} else {
lhsIndex += 1
rhsIndex += 1
}
}
return ComparisonResult.orderedSame
}
``` // XCTAssertTrue failedenum ComparisonResult {
case orderedSame
case orderedAscending
case orderedDescending
}
func compareVersions(_ lhs: String, _ rhs: String) -> ComparisonResult {
let lhsParts = lhs.split(separator: ".")
let rhsParts = rhs.split(separator: ".")
var lhsIndex = 0
var rhsIndex = 0
while lhsIndex < lhsParts.count && rhsIndex < rhsParts.count {
let lhsPart = lhsParts[lhsIndex]
let rhsPart = rhsParts[rhsIndex]
if lhsPart.hasPrefix("alpha") || lhsPart.hasPrefix("beta") {
lhsIndex += 1
continue
}
if rhsPart.hasPrefix("alpha") || rhsPart.hasPrefix("beta") {
rhsIndex += 1
continue
}
if lhsPart.hasPrefix("0") || rhsPart.hasPrefix("0") {
let lhsInt = Int(lhsPart) ?? 0
let rhsInt = Int(rhsPart) ?? 0
if lhsInt < rhsInt {
return .orderedAscending
} else if lhsInt > rhsInt {
return .orderedDescending
}
} else {
if lhsPart < rhsPart {
return .orderedAscending
} else if lhsPart > rhsPart {
return .orderedDescending
}
}
lhsIndex += 1
rhsIndex += 1
}
if lhsIndex < lhsParts.count {
return .orderedDescending
} else if rhsIndex < rhsParts.count {
return .orderedAscending
}
return .orderedSame
}```swift
enum ComparisonResult {
case orderedSame
case orderedAscending
case orderedDescending
}
// Function that compares two version number strings (created with respect of semantic versioning specification including "alpha" and "beta" tags) and returning their ordering as a value of type ComparisonResult.
func compareVersions(_ lhs: String, _ rhs: String) -> ComparisonResult {
let lhsParts = lhs.split(separator: ".")
let rhsParts = rhs.split(separator: ".")
var lhsIndex = 0
var rhsIndex = 0
while lhsIndex < lhsParts.count && rhsIndex < rhsParts.count {
let lhsPart = lhsParts[lhsIndex]
let rhsPart = rhsParts[rhsIndex]
if lhsPart.hasPrefix("alpha") || lhsPart.hasPrefix("beta") {
lhsIndex += 1
continue
}
if rhsPart.hasPrefix("alpha") || rhsPart.hasPrefix("beta") {
rhsIndex += 1
continue
}
if lhsPart.hasPrefix("0") || rhsPart.hasPrefix("0") {
let lhsInt = Int(lhsPart) ?? 0
let rhsInt = Int(rhsPart) ?? 0
if lhsInt < rhsInt {
return .orderedAscending
} else if lhsInt > rhsInt {
return .orderedDescending
}
} else {
if lhsPart < rhsPart {
return .orderedAscending
} else if lhsPart > rhsPart {
return .orderedDescending
}
}
lhsIndex += 1
rhsIndex += 1
}
if lhsIndex < lhsParts.count {
return .orderedDescending
} else if rhsIndex < rhsParts.count {
return .orderedAscending
}
return .orderedSame
}
``` // XCTAssertTrue failed