打開 Combine 的引擎蓋看看

2020 年 iPlayground 演講：
Combine 是怎麼在 Swift 原本的物件導向設計與指令式設計的架構下，編寫出使用方法完全不一樣的 Combine。這個 Session 將討論 Combine 關鍵角色: Publishers、Subscribers、Operators，了解 Combine 如何運作！

1. 打開 Combine 的引擎蓋看看 SWIFT, COMBINE, REACTIVE IPLAYGROUND 2020 游諭 What’s under the hood？
2. 游諭（@ytyubox） 
 ⾃學程式 iOS - 2018 iT 邦幫忙鐵⼈賽： 
 30 天了解 Swift 的 Combine 
 30 天從 Swift 學會 Objective-C $> whoami 2
3. Agenda Short Introductions 簡單的 Combine 應⽤ combine 的⾓⾊ Behavior test 更進階的 Combine 3 ⽬錄
4. Agenda Short Introductions 簡單的 Combine 應⽤ combine 的⾓⾊ Behavior test 更進階的 Combine 4 ⽬錄 50 % +
5. 5 開始之前
6. 6 ，這個 Session 將會 介紹如何入⾨ Combine 並不包含解釋 Framework 內部原始碼 開始之前
7. Short Introductions 7
9. 9 SwiftUI
10. 10 Combine SwiftUI
11. RxSwift 11 https://github.com/ReactiveX https://github.com/ReactiveCocoa/ReactiveSwift https://developer.apple.com/videos/wwdc2019 Combine
12. 12 https://github.com/ReactiveX https://github.com/ReactiveCocoa/ReactiveSwift https://developer.apple.com/videos/wwdc2019 Functional Reactive Programming Combine RxSwift
13. 13 A unified, declarative API for 
 processing values over time. By WWDC 2019: Introducing Combine Functional Reactive Programming Combine
14. 14 A unified, declarative API for 
 processing values over time. By WWDC 2019: Introducing Combine Functional Reactive Programming Combine
15. 15 A unified, declarative API for 
 processing values over time. Generic Composition f i rst Request driven type safe By WWDC 2019: Introducing Combine Combine
16. 打開 Combine 會發現什麼？ 16
17. 17 打開 Combine 發現了⼀隻貓
18. Asynchronous Programming 18
19. 來⾃ Apple / Combine 19 透過組合處理事件的運算⼦來定制異步事件的應對⽅式。
20. 來⾃ Apple / Combine 20 透過組合處理事件的運算⼦來定制異步事件的應對⽅式。
21. 來⾃ Apple / Combine 21 透過組合處理事件的運算⼦來定制異步事件的應對⽅式。 注意 Apple 這裡的非同步不是指 Dispatch framework
22. 22 asynchronous programing 非同步程式設計
23. Property Observers ( set / didSet ) Target / Action ( @IBAction ) Notification Center Ad-hoc Callbacks 23 asynchronous programing 非同步程式設計 URLSession.dataTask(with:, completionHandler:) Key-Value Observing
24. 24 Key-Value Observing 複習⼀下
25. 25 class KVOTarget: NSObject { @objc dynamic var value = 0 } let target = KVOTarget() var captured = [Int?]() let kvoToken = target.observe(\.value, options: .new) { (target, change) in captured.append(change.newValue) } XCTAssertEqual(captured, []) target.value = 1 target.value = 2 XCTAssertEqual(captured, [1, 2]) kvoToken.invalidate() target.value = 3 XCTAssertEqual(captured, [1, 2]) Key-Value Observing 複習⼀下
26. 26 class KVOTarget: NSObject { @objc dynamic var value = 0 } let target = KVOTarget() var captured = [Int?]() let kvoToken = target.observe(\.value, options: .new) { (target, change) in captured.append(change.newValue) } XCTAssertEqual(captured, []) target.value = 1 target.value = 2 XCTAssertEqual(captured, [1, 2]) kvoToken.invalidate() target.value = 3 XCTAssertEqual(captured, [1, 2]) Key-Value Observing 複習⼀下
27. 27 class KVOTarget: NSObject { @objc dynamic var value = 0 } let target = KVOTarget() var captured = [Int?]() let kvoToken = target.observe(\.value, options: .new) { (target, change) in captured.append(change.newValue) } XCTAssertEqual(captured, []) target.value = 1 target.value = 2 XCTAssertEqual(captured, [1, 2]) kvoToken.invalidate() target.value = 3 XCTAssertEqual(captured, [1, 2]) Key-Value Observing 複習⼀下
28. 28 class KVOTarget: NSObject { @objc dynamic var value = 0 } let target = KVOTarget() var captured = [Int?]() let kvoToken = target.observe(\.value, options: .new) { (target, change) in captured.append(change.newValue) } XCTAssertEqual(captured, []) target.value = 1 target.value = 2 XCTAssertEqual(captured, [1, 2]) kvoToken.invalidate() target.value = 3 XCTAssertEqual(captured, [1, 2]) Key-Value Observing 複習⼀下
29. 簡單 Combine 應⽤ 29
30. 30 import Combine
31. 31 URLSession.shared.dataTaskPublisher(for: aURL) import Combine
32. 32 URLSession.shared.dataTaskPublisher(for: aURL) Publisher import Combine
33. 33 URLSession.shared.dataTaskPublisher(for: aURL) .map(\.data) .decode(type: MyModel.self, decoder: JSONDecoder()) Publisher import Combine
34. 34 URLSession.shared.dataTaskPublisher(for: aURL) .map(\.data) .decode(type: MyModel.self, decoder: JSONDecoder()) .sink(receiveCompletion: self.receiveCompletionMethod, 
 receiveValue: self.receiveValueMethod) AnyCancellable import Combine
35. 35 import Combine func greet(person: String) throws -> String { let greeting = "Hello, " + person + "!" return greeting }
36. 36 func greetPublisher(person: String) -> AnyPublisher<String,Error> { return Just(person) .prepend("Hello, ") .append("!") .reduce("", +) .eraseToAnyPublisher() } func greet(person: String) throws -> String { let greeting = "Hello, " + person + "!" return greeting } import Combine
37. Combine ⾓⾊ 37
38. 38 import Combine protocol Publisher { associatedtype Output associatedtype Failure : Error func receive<S: Subscriber>(subscriber: S) where Self.Failure == S.Failure, Self.Output == S.Input }
39. 39 import Combine protocol Publisher { ... }
40. 40 import Combine protocol Publisher { ... } protocol Subscriber { associatedtype Input associatedtype Failure : Error func receive(subscription: Subscription) func receive(_ input: Self.Input) -> Subscribers.Demand func receive(completion: Subscribers.Completion<Self.Failure>) }
41. 41 import Combine protocol Publisher { ... } protocol Subscriber { ... }
42. protocol Publisher { ... } protocol Subscriber { ... } 42 Subscriber Publisher import Combine
43. Subscriber Publisher 43
44. Subscriber Publisher 44
45. Subscriber Publisher 45
46. Subscriber Publisher 46
47. Subscriber Publisher 47
48. Subscriber Publisher 48
49. Subscriber 49
50. 50 Combine Pattern From WWDC 2019 - Introducing Combine
51. 51 Combine Pattern From WWDC 2019 - Introducing Combine 來⾃與 Introducing Combine https://developer.apple.com/videos/play/wwdc2019/722/
52. Subscriber Publisher subscribe( ) is attached Publisher Subscriber Combine Pattern From WWDC 2019 - Introducing Combine 52
53. Subscriber Publisher subscribe( ) is attached Publisher Subscriber Subscription receive(subscription: ) sends Publisher Subscription Combine Pattern From WWDC 2019 - Introducing Combine 53
54. Subscriber Publisher subscribe( ) is attached Publisher Subscriber request(_: Demand) requests N values Subscriber Subscription receive(subscription: ) sends Publisher Subscription Combine Pattern From WWDC 2019 - Introducing Combine 54
55. Subscriber Publisher subscribe( ) is attached Publisher Subscriber receive(_: Input) sends N values or less Publisher request(_: Demand) requests N values Subscriber Subscription receive(subscription: ) sends Publisher Subscription Combine Pattern From WWDC 2019 - Introducing Combine 55
56. Subscriber Publisher subscribe( ) is attached Publisher Subscriber receive(_: Input) sends N values or less Publisher receive(completion:) sends completion Publisher request(_: Demand) requests N values Subscriber Subscription receive(subscription: ) sends Publisher Subscription Combine Pattern From WWDC 2019 - Introducing Combine 56
57. 57 如果對⼀個 Publisher 重複 Subscribe 呢？
58. Publisher Subscriber 58 Subscriber No. 2
59. Publisher Subscriber 59 Subscriber No. 2
60. Publisher Subscriber 60 Subscriber No. 2
61. Publisher Subscriber 61 Subscriber No. 2
62. Publisher Subscriber 62 Subscriber No. 2 Copied Publisher
63. Publisher Subscriber 63 Subscriber No. 2 Copied Publisher
64. Publisher Subscriber 64 Subscriber No. 2 Copied Publisher
65. Publisher Subscriber 65 Subscriber No. 2 Copied Publisher
66. Subscriber Publisher subscribe( ) receive(_: Input) sends N values or less Publisher receive(completion:) sends completion Publisher request(_: Demand) Subscription receive(subscription: ) is attached Publisher Subscriber requests N values Subscriber sends Publisher Subscription Combine Pattern From WWDC 2019 - Introducing Combine 66
67. receive(subscription: ) Publisher 67 Subscriber subscribe( ) request(_: Demand) receive(_: Input) receive(completion:) Subscription subscribe( ) receive(_: Input) sends N values or less receive(completion:) sends completion request(_: Demand) Subscription Combine Pattern From my perspective Subscription Subscription is attached Publisher Subscriber requests N values Subscriber sends Publisher Subscription
68. Subscription Publisher Subscriber 68
69. Combine Operator 69
70. Publisher <Int> Publisher <String> Mapper <Int, String> 70 Operator
71. 71 Operator 其實是 decorator pattern
72. Publisher Operator class Operator: Publisher { let concrete: Publisher } is a has a 72 decorator pattern
73. client decor 1 driver decor 2 action 73 decorator pattern
74. client decor 1 driver decor 2 action addBehavior 74 decorator pattern
75. client decor 1 driver decor 2 action action 75 decorator pattern addBehavior
76. client decor 1 driver decor 2 action action action 76 decorator pattern addBehavior
77. addBehavior client decor 1 driver decor 2 action action action 77 decorator pattern addBehavior
78. client decor 1 driver decor 2 action action action 78 decorator pattern addBehavior addBehavior addBehavior
79. Mazinger Z: a Japanese super robot manga series written and illustrated by Go Naga Has a Man, is a Man. 79 無敵鐵⾦剛
80. 80 Behavior tests
81. 81 AnyCancellable deinit 會⾃動 Cancel
82. 82 let subject = PassthroughSubject<Int, Never>() var received = [Event<Int, Never>]() weak var weakCancellable: AnyCancellable? do { let anyCancellable = subject .sink(event: { e in received.append(e) } ) weakCancellable = anyCancellable subject.send(1) } XCTAssertNil(weakCancellable) subject.send(2) XCTAssertEqual(received, [1]) AnyCancellable deinit 會⾃動 Cancel
83. 83 let subject = PassthroughSubject<Int, Never>() var received = [Event<Int, Never>]() weak var weakCancellable: AnyCancellable? do { let anyCancellable = subject .sink(event: { e in received.append(e) } ) weakCancellable = anyCancellable subject.send(1) } XCTAssertNil(weakCancellable) subject.send(2) XCTAssertEqual(received, [1]) AnyCancellable deinit 會⾃動 Cancel
84. 84 let subject = PassthroughSubject<Int, Never>() var received = [Event<Int, Never>]() weak var weakCancellable: AnyCancellable? do { let anyCancellable = subject .sink(event: { e in received.append(e) } ) weakCancellable = anyCancellable subject.send(1) } XCTAssertNil(weakCancellable) subject.send(2) XCTAssertEqual(received, [1]) AnyCancellable deinit 會⾃動 Cancel
85. 85 let subject = PassthroughSubject<Int, Never>() var received = [Event<Int, Never>]() weak var weakCancellable: AnyCancellable? do { let anyCancellable = subject .sink(event: { e in received.append(e) } ) weakCancellable = anyCancellable subject.send(1) } XCTAssertNil(weakCancellable) subject.send(2) XCTAssertEqual(received, [1]) AnyCancellable deinit 會⾃動 Cancel
86. 86 let subject = PassthroughSubject<Int, Never>() var received = [Event<Int, Never>]() weak var weakCancellable: AnyCancellable? do { let anyCancellable = subject .sink(event: { e in received.append(e) } ) weakCancellable = anyCancellable subject.send(1) } XCTAssertNil(weakCancellable) subject.send(2) XCTAssertEqual(received, [1]) AnyCancellable deinit 會⾃動 Cancel
87. 87 let subject = PassthroughSubject<Int, Never>() var received = [Event<Int, Never>]() weak var weakCancellable: AnyCancellable? do { let anyCancellable = subject .sink(event: { e in received.append(e) } ) weakCancellable = anyCancellable subject.send(1) } XCTAssertNil(weakCancellable) subject.send(2) XCTAssertEqual(received, [1]) AnyCancellable deinit 會⾃動 Cancel
88. 88 NSKeyValueObservation deinit 也會⾃動 Cancel
89. 89 let target = KVOTarget() var captured = [Int?]() weak var weakKvoToken: NSKeyValueObservation? do { let token = target.observe(\.value, options: .new) { (target, change) in captured.append(change.newValue) } weakKvoToken = token target.value = 1 target.value = 2 XCTAssertEqual(captured, [1, 2]) } XCTAssertNil(weakKvoToken) target.value = 3 XCTAssertEqual(captured, [1, 2]) NSKeyValueObservation deinit 也會⾃動 Cancel
90. let target = KVOTarget() var captured = [Int?]() weak var weakKvoToken: NSKeyValueObservation? do { let token = target.observe(\.value, options: .new) { (target, change) in captured.append(change.newValue) } weakKvoToken = token target.value = 1 target.value = 2 XCTAssertEqual(captured, [1, 2]) } XCTAssertNil(weakKvoToken) target.value = 3 XCTAssertEqual(captured, [1, 2]) 90 NSKeyValueObservation deinit 也會⾃動 Cancel
91. let target = KVOTarget() var captured = [Int?]() weak var weakKvoToken: NSKeyValueObservation? do { let token = target.observe(\.value, options: .new) { (target, change) in captured.append(change.newValue) } weakKvoToken = token target.value = 1 target.value = 2 XCTAssertEqual(captured, [1, 2]) } XCTAssertNil(weakKvoToken) target.value = 3 XCTAssertEqual(captured, [1, 2]) 91 NSKeyValueObservation deinit 也會⾃動 Cancel
92. 92 使⽤ Publisher.subscribe 會 Retain Sink
93. 93 let subject = PassthroughSubject<Int, Never>() var received = [Event<Int, Never>]() weak var weakSink: Subscribers.Sink<Int, Never>? do { let sink = Subscribers.Sink<Int, Never>{ received.append(.value($0)) } weakSink = sink subject.subscribe(sink) subject.send(1) } XCTAssertNotNil(weakSink) subject.send(2) weakSink?.cancel() XCTAssertNil(weakSink) subject.send(3) XCTAssertEqual(received, [1, 2]) 使⽤ Publisher.subscribe 會 Retain Sink
94. 94 let subject = PassthroughSubject<Int, Never>() var received = [Event<Int, Never>]() weak var weakSink: Subscribers.Sink<Int, Never>? do { let sink = Subscribers.Sink<Int, Never>{ received.append(.value($0)) } weakSink = sink subject.subscribe(sink) subject.send(1) } XCTAssertNotNil(weakSink) subject.send(2) weakSink?.cancel() XCTAssertNil(weakSink) subject.send(3) XCTAssertEqual(received, [1, 2]) 使⽤ Publisher.subscribe 會 Retain Sink
95. 95 let subject = PassthroughSubject<Int, Never>() var received = [Event<Int, Never>]() weak var weakSink: Subscribers.Sink<Int, Never>? do { let sink = Subscribers.Sink<Int, Never>{ received.append(.value($0)) } weakSink = sink subject.subscribe(sink) subject.send(1) } XCTAssertNotNil(weakSink) subject.send(2) weakSink?.cancel() XCTAssertNil(weakSink) subject.send(3) XCTAssertEqual(received, [1, 2]) 使⽤ Publisher.subscribe 會 Retain Sink
96. 96 let subject = PassthroughSubject<Int, Never>() var received = [Event<Int, Never>]() weak var weakSink: Subscribers.Sink<Int, Never>? do { let sink = Subscribers.Sink<Int, Never>{ received.append(.value($0)) } weakSink = sink subject.subscribe(sink) subject.send(1) } XCTAssertNotNil(weakSink) subject.send(2) weakSink?.cancel() XCTAssertNil(weakSink) subject.send(3) XCTAssertEqual(received, [1, 2]) 使⽤ Publisher.subscribe 會 Retain Sink
97. 97 let subject = PassthroughSubject<Int, Never>() var received = [Event<Int, Never>]() weak var weakSink: Subscribers.Sink<Int, Never>? do { let sink = Subscribers.Sink<Int, Never>{ received.append(.value($0)) } weakSink = sink subject.subscribe(sink) subject.send(1) } XCTAssertNotNil(weakSink) subject.send(2) weakSink?.cancel() XCTAssertNil(weakSink) subject.send(3) XCTAssertEqual(received, [1, 2]) 使⽤ Publisher.subscribe 會 Retain Sink
98. 98 let subject = PassthroughSubject<Int, Never>() var received = [Event<Int, Never>]() weak var weakSink: Subscribers.Sink<Int, Never>? do { let sink = Subscribers.Sink<Int, Never>{ received.append(.value($0)) } weakSink = sink subject.subscribe(sink) subject.send(1) } XCTAssertNotNil(weakSink) subject.send(2) weakSink?.cancel() XCTAssertNil(weakSink) subject.send(3) XCTAssertEqual(received, [1, 2]) 使⽤ Publisher.subscribe 會 Retain Sink
99. 更進階的 Combine 99
100. 在開始之前：習慣 Value over time 100
101. 複習⼀下 ”國中物理“ 直線等加速度運動圖形 101
102. 複習⼀下 ”國中物理“ 直線等加速度運動圖形 102 時間 速 度 時間 位 移 時間 加 速 度
103. 複習⼀下 ”國中物理“ 直線等加速度運動圖形 103 時間 速 度 時間 位 移 時間 加 速 度
104. 104 彈珠圖 marble diagram 事件 Event 截⽌ Completion ❌ Error 事件流 Stream
105. 105 彈珠圖 marble diagram 事件流 Stream ❌ Error
106. 106 Publisher Subscribe 多次
107. 107 Subscriber Subscriber Publisher Publisher Subscribe 多次
108. 108 Subscriber Subscriber Publisher Publisher Subscribe 多次
109. 109 Subscriber Subscriber Publisher Publisher Subscribe 多次
110. 110 Subscriber Subscriber Publisher Publisher Subscribe 多次
111. 111 Subscriber Subscriber Publisher Subject Publisher Subscribe 多次
112. 112 Subscriber Subscriber Publisher Subject Publisher Subscribe 多次
113. 113 Subscriber Subscriber Publisher Subject Publisher Subscribe 多次
114. 114 Subscriber Subscriber Publisher Subject Publisher Subscribe 多次
115. 115 Subscriber Subscriber Publisher Subject Publisher Subscribe 多次
116. 116 Subscriber Subscriber Publisher Subject Publisher Subscribe 多次
117. 117 Hot / Cold Publisher
119. 119 Cold Publisher
120. Subscriber Publisher 120 Cold Publisher
121. Subscriber Publisher 121 Cold Publisher
122. Subscriber Publisher 122 Cold Publisher
123. Subscriber Publisher 123 Cold Publisher
124. 124 Hot Publisher
125. Publisher 125 Hot Publisher
126. Publisher 126 Hot Publisher
127. Subscriber Publisher 127 Hot Publisher
128. Subscriber Publisher 128 Hot Publisher
129. Subscriber Publisher 129 Hot Publisher
130. Subscriber Publisher 130 Hot Publisher
131. 131 Passthrough Subject CurrentValue Subject
132. 132 Passthrough Subject CurrentValue Subject
133. 133 Passthrough Subject CurrentValue Subject
134. 134 Passthrough Subject CurrentValue Subject
135. 135 Passthrough Subject CurrentValue Subject
136. 136 Passthrough Subject CurrentValue Subject
137. 137 let subjectA = PassthroughSubject<Int, Never>() let scanB = subjectA.scan(0, +) var receivedC = [Event<Int, Never>]() let sinkC = scanB.sink{ e in receivedC.append(e) } subjectA.send(1...2) var receivedD = [Event<Int, Never>]() let sinkD = scanB.sink{ e in receivedD.append(e) } subjectA.send(3...4) XCTAssertEqual(receivedC, [1, 3, 6, 10]) // 0 + 1...4 XCTAssertEqual(receivedD, [3, 7]) // 0 + 3...4
138. 138 let subjectA = PassthroughSubject<Int, Never>() let scanB = subjectA.scan(0, +) var receivedC = [Event<Int, Never>]() let sinkC = scanB.sink{ e in receivedC.append(e) } subjectA.send(1...2) var receivedD = [Event<Int, Never>]() let sinkD = scanB.sink{ e in receivedD.append(e) } subjectA.send(3...4) XCTAssertEqual(receivedC, [1, 3, 6, 10]) // 0 + 1...4 XCTAssertEqual(receivedD, [3, 7]) // 0 + 3...4
139. 139 let subjectA = PassthroughSubject<Int, Never>() let scanB = subjectA.scan(0, +) var receivedC = [Event<Int, Never>]() let sinkC = scanB.sink{ e in receivedC.append(e) } subjectA.send(1...2) var receivedD = [Event<Int, Never>]() let sinkD = scanB.sink{ e in receivedD.append(e) } subjectA.send(3...4) XCTAssertEqual(receivedC, [1, 3, 6, 10]) // 0 + 1...4 XCTAssertEqual(receivedD, [3, 7]) // 0 + 3...4
140. FlatMap 140
141. 之前複習⼀下 向量投影（內積） 141 FlatMap
142. 142 FlatMap
143. 143 FlatMap
144. 144 FlatMap
145. 145 FlatMap
146. 146 FlatMap
147. Error handling By Catch 147 Publisher Subscriber Catch
148. Error handling By Catch 148 Publisher Subscriber Catch
149. Error handling By Catch 149 Publisher Subscriber Catch
150. Error handling By Catch 150 Publisher Subscriber Catch
151. Error handling By Catch 151 Subscriber Catch
152. Error handling By Catch 152 Subscriber Catch Recovery Publisher
153. Error handling By Catch 153 Subscriber Catch Recovery Publisher
154. Error handling By Catch 154 Subscriber Catch Recovery Publisher
155. Error From TryMap 155 Publisher Subscriber Catch TryMap
156. Error From TryMap 156 Publisher Subscriber Catch TryMap
157. Error From TryMap 157 Publisher Subscriber Catch TryMap
158. Error From TryMap 158 Publisher Subscriber Catch TryMap
159. Error From TryMap 159 Publisher Subscriber Catch TryMap
160. Error From TryMap 160 Publisher Subscriber Catch TryMap
161. Error From TryMap 161 Subscriber Catch
162. Error From TryMap 162 Subscriber Catch Recovery Publisher
163. Error From TryMap 163 Subscriber Catch Recovery Publisher
164. Error From TryMap 164 Subscriber Catch Recovery Publisher
165. 使⽤ FlatMap 導流 165 Publisher Subscriber FlatMap
166. 使⽤ FlatMap 導流 166 Publisher Subscriber FlatMap
167. 使⽤ FlatMap 導流 167 Publisher Subscriber Catch TryMap FlatMap Catch TryMap
168. 使⽤ FlatMap 導流 168 Publisher Subscriber Catch TryMap FlatMap Catch TryMap
169. 使⽤ FlatMap 導流 169 Publisher Subscriber Catch TryMap FlatMap Catch TryMap
170. 使⽤ FlatMap 導流 170 Publisher Subscriber Catch FlatMap Catch Recovery Publisher
171. 使⽤ FlatMap 導流 171 Publisher Subscriber FlatMap
172. 使⽤ FlatMap 導流 172 Publisher Subscriber FlatMap
173. 使⽤ FlatMap 導流 173 Publisher Subscriber FlatMap
174. 使⽤ FlatMap 導流 174 Publisher Subscriber FlatMap
175. 使⽤ FlatMap 導流 175 Publisher Subscriber FlatMap Catch TryMap Catch TryMap
176. 使⽤ FlatMap 導流 176 Publisher Subscriber FlatMap Catch TryMap Catch TryMap
177. 使⽤ FlatMap 導流 177 Publisher Subscriber FlatMap
178. 使⽤ FlatMap 導流 178 Publisher Subscriber FlatMap ✅
179. 聽完這個 Session 之後呢？ 179
180. Apple/Swift Combine Extension 180 https://github.com/apple/swift/tree/main/stdlib/public/Darwin/Foundation
181. Reactive Programming Taiwan (RxSwift/Combine) 加入 Telegram 台灣社群 181
182. 加入 Combine Community 182
183. 183 watchOS tvOS iOS macOS Combine
184. 184 watchOS tvOS iOS macOS Linux WASI
185. Apple Combine Documents WWDC 2019 Session 722, Session 721 cocoawithlove by Matt Gallagher - 22 short tests of Combine 
 https://www.cocoawithlove.com/blog/twenty-two-short-tests-of-combine-part-1.html OpenCombine 
 https://github.com/OpenCombine ReactiveX.io 
 http://reactivex.io/ ReactiveCocoa.io 
 https://reactivecocoa.io/ 參考資料 185
186. 結論 186
187. 187 Combine 酷嗎？
188. 188 Combine 酷嗎？
189. 189 Combine 酷嗎？ Combine 好學嗎？
190. 190 Combine 酷嗎？ Combine 好學嗎？ ✅
191. 191 Combine 酷嗎？ Combine 好學嗎？ ✅ Combine 好⽤嗎？
192. 192 Combine 酷嗎？ Combine 好學嗎？ ✅ Combine 好⽤嗎？
193. 193 ✅ Combine