UnderstandingYourToddler.pdf

Often we can go back and look at someone's toddler years and see signs of the person they would become. In this talk we look at the proposals for Swift 3 and imagine the language Swift will become.

Transcript

3. ?
7. Understanding Your Toddler iOSConf 2016 Daniel H Steinberg @dimsumthinking
8. Understanding Your Toddler iOSConf 2016 Daniel H Steinberg @dimsumthinking
9. Understanding Your Toddler iOSConf 2016 Daniel H Steinberg @dimsumthinking No, this is not the same talk I gave last week at UIKonf
10. Summer 2010
13. Summer 2010
14. Xcode 4 shipped
15. Xcode IB
17. 18 months
19. Xcode 4.2
20. LLVM Only
21. iOS 5
22. ARC
23. WWDC 2014
25. Swift 1.0
26. Swift 1.1
27. Swift 1.2
28. WWDC 2015
29. "Swift will be open sourced by the end of this year"
30. December 3, 2015
33. Proposals from the Community
34. PRs from the Community
35. Committers
36. Conversation
37. Swift Evolution
38. Open
39. Swift 3
40. "We have had a focus on getting to source stability"
41. Swift 3 focus on source stability
42. API design guidelines Focus and refine the language Adoption of naming guidelines in key APIs Automatic application of naming guidelines to imported Objective-C APIs Swiftification of imported Objective-C APIs Improvements to tooling quality
43. API design guidelines Focus and refine the language Adoption of naming guidelines in key APIs Automatic application of naming guidelines to imported Objective-C APIs Swiftification of imported Objective-C APIs Improvements to tooling quality
44. API design guidelines Focus and refine the language Adoption of naming guidelines in key APIs Automatic application of naming guidelines to imported Objective-C APIs Swiftification of imported Objective-C APIs Improvements to tooling quality
45. API design guidelines Focus and refine the language Adoption of naming guidelines in key APIs Automatic application of naming guidelines to imported Objective-C APIs Swiftification of imported Objective-C APIs Improvements to tooling quality
46. API design guidelines Focus and refine the language Adoption of naming guidelines in key APIs Automatic application of naming guidelines to imported Objective-C APIs Swiftification of imported Objective-C APIs Improvements to tooling quality
47. API design guidelines Focus and refine the language Adoption of naming guidelines in key APIs Automatic application of naming guidelines to imported Objective-C APIs Swiftification of imported Objective-C APIs Improvements to tooling quality
48. Swift 3 focus on source stability
49. A Few Previews of Coming Attractions
50. 0025 - Scoped Access Levels
51. public internal private
52. public internal private
53. public internal private
54. public internal private
55. public internal fileprivate
56. public internal fileprivate private
57. class MyClass { private var myProperty = "Hello" private func myPrivateMethod() { print(myProperty) } fileprivate func myFilePrivateMethod(numberOfTimes times: Int) { for _ in 1 ... times { myPrivateMethod() } } } extension MyClass { func myExtensionMethod(numberOfTimes times: Int) { myFilePrivateMethod(numberOfTimes: times) } }
58. class MyClass { private var myProperty = "Hello" private func myPrivateMethod() { print(myProperty) } fileprivate func myFilePrivateMethod(numberOfTimes times: Int) { for _ in 1 ... times { myPrivateMethod() } } } extension MyClass { func myExtensionMethod(numberOfTimes times: Int) { myFilePrivateMethod(numberOfTimes: times) } }
59. class MyClass { private var myProperty = "Hello" private func myPrivateMethod() { print(myProperty) } fileprivate func myFilePrivateMethod(numberOfTimes times: Int) { for _ in 1 ... times { myPrivateMethod() } } } extension MyClass { func myExtensionMethod(numberOfTimes times: Int) { myFilePrivateMethod(numberOfTimes: times) } }
60. class MyClass { private var myProperty = "Hello" private func myPrivateMethod() { print(myProperty) } fileprivate func myFilePrivateMethod(numberOfTimes times: Int) { for _ in 1 ... times { myPrivateMethod() } } } extension MyClass { func myExtensionMethod(numberOfTimes times: Int) { myFilePrivateMethod(numberOfTimes: times) } }
61. class MyClass { private var myProperty = "Hello" private func myPrivateMethod() { print(myProperty) } fileprivate func myFilePrivateMethod(numberOfTimes times: Int) { for _ in 1 ... times { myPrivateMethod() } } } extension MyClass { func myExtensionMethod(numberOfTimes times: Int) { myFilePrivateMethod(numberOfTimes: times) } }
62. public internal fileprivate private
63. 0004 - Remove ++ and —
64. while count < upperLimit { print( myArray[count++]) }
65. while count < upperLimit { print( myArray[count++]) }
66. while count < upperLimit { print( myArray[count]) count += 1 }
67. 0007 - Remove C Style for loops with conditions and incrementors
68. for (int i = 0; i < array.count; i++)
69. for (int i = 0; i < array.count; i++)
70. 0053 - Remove explicit use of let from Function Parameters
71. func double(input: Int) -> Int { // ... }
72. func double(let input: Int) -> Int { // ... }
73. func double(let input: Int) -> Int { // ... }
74. 0003 - Remove var from Function Parameters
75. func double(input: Int) -> Int { input = input * 2 return input }
76. func double(var input: Int) -> Int { input = input * 2 return input }
77. func double(var input: Int) -> Int { input = input * 2 return input }
78. func double(input: Int) -> Int { var localInput = input localInput = localInput * 2 return localInput }
79. func double(input: Int) -> Int { var localInput = input localInput = localInput * 2 return localInput }
80. func double(input: Int) -> Int { var input = input input = input * 2 return input } Name Shadowing
81. func double(input: Int) -> Int { var input = input input = input * 2 return input }
82. 0031 - Adjusting inout Declarations for Type Decoration
83. func double(input: Int) { input = input * 2 }
84. func double(inout input: Int) { input = input * 2 }
85. func double(inout input: Int) { input = input * 2 }
86. func double(input: inout Int) { input = input * 2 }
87. 0053 - Limiting inout capture to @noescape context
88. func escape(f: () -> ()) {} func example(inout x: Int) { escape { _ = x } }
89. func escape(f: () -> ()) {} func example(inout x: Int) { escape { _ = x } }
90. func escape(f: () -> ()) {} func example(inout x: Int) { escape { _ = x } }
91. func escape(f: () -> ()) {} func example(inout x: Int) { escape { _ = x } }
92. func escape(f: () -> ()) {} func example(inout x: Int) { escape { _ = x } }
93. func escape(f: () -> ()) {} func example(inout x: Int) { escape { _ = x } }
94. func escape(f: () -> ()) {} func example(inout x: Int) { escape { _ = x } }
95. func noEscape(@noescape f: () -> ()) {} func example(inout x: Int) { noEscape { _ = x } }
96. func noEscape(@noescape f: () -> ()) {} func example(inout x: Int) { noEscape { _ = x } } safe because @noescape => closure can't be called after function returns
97. func escape(f: () -> ()) {} func example(inout x: Int) { escape { _ = x } }
98. func escape(f: () -> ()) {} func example(inout x: Int) { escape {[x] in _ = x } }
99. func escape(f: () -> ()) {} func example(inout x: Int) { escape {[x] in _ = x } } [x] is a capture list a constant is initialized to have the value of x
100. 0049 - Move @noescape and @autoclosure to be type attributes
101. func noEscape(@noescape f: () -> ()) {}
102. func noEscape(f: @noescape () -> ()) {}
103. func noEscape(f: @autoclosure () -> ()) {}
104. 0002 - Remove currying func declaration syntax
105. 0002 - Remove currying func declaration syntax
106. 0002 - Remove currying func declaration syntax
107. func curried(x: Int)(y: Int) -> Int { return {(y: Int) -> Int in return x * y } } curried(7)(8)
108. func curried(x: Int)(y: Int) -> Int { return {(y: Int) -> Int in return x * y } } curried(7)(8)
109. func curried(x: Int)(y: Int) -> Int { return {(y: Int) -> Int in return x * y } } curried(7)(8)
110. func curried(x: Int)(y: Int) -> Int { return {(y: Int) -> Int in return x * y } } curried(7)(8)
111. func curried(x: Int)(y: Int) -> Int { return {(y: Int) -> Int in return x * y } } curried(7)(8) 7 * y
112. func curried(x: Int)(y: Int) -> Int { return {(y: Int) -> Int in return x * y } } curried(7)(8) 7 * 8
113. func curried(x: Int)(y: Int) -> Int { return {(y: Int) -> Int in return x * y } } curried(7)(8)
114. func curried(x: Int)(y: Int) -> Int { return {(y: Int) -> Int in return x * y } } curried(7)(8)
115. func curried(x: Int)(y: Int) -> Int { return {(y: Int) -> Int in return x * y } } curried(7)(8)
116. func curried(x: Int) -> (y: Int) -> Int { return {(y: Int) -> Int in return x * y } } curried(7)(8)
117. func curried(x: Int) -> (y: Int) -> Int { return {(y: Int) -> Int in return x * y } } curried(7)(8)
118. func curried(x: Int) -> (y: Int) -> Int { return {(y: Int) -> Int in return x * y } } curried(7)(8)
119. func curried(x: Int) -> (y: Int) -> Int { return {(y: Int) -> Int in return x * y } } curried(7)(8)
120. func curried(x: Int) -> (y: Int) -> Int { return {(y: Int) -> Int in return x * y } } curried(7)(8)
121. Testing
122. Playgrounds
123. Package Manager
124. Objective-C
125. 0022 - Referencing the Obj-C selector of a method
126. class MyClass : NSObject { func callbackMethod(with notification: NSNotification){} func setNotification() { let center = NSNotificationCenter.defaultCenter() center .addObserver(self, selector: "callbackMethod", name: NSApplicationWillResignActiveNotification, object: NSApplication.sharedApplication()) } }
127. class MyClass : NSObject { func callbackMethod(with notification: NSNotification){} func setNotification() { let center = NSNotificationCenter.defaultCenter() center .addObserver(self, selector: "callbackMethod", name: NSApplicationWillResignActiveNotification, object: NSApplication.sharedApplication()) } }
128. class MyClass : NSObject { func callbackMethod(with notification: NSNotification){} func setNotification() { let center = NSNotificationCenter.defaultCenter() center .addObserver(self, selector: "callbackMethod", name: NSApplicationWillResignActiveNotification, object: NSApplication.sharedApplication()) } }
129. class MyClass : NSObject { func callbackMethod(with notification: NSNotification){} func setNotification() { let center = NSNotificationCenter.defaultCenter() center .addObserver(self, selector: "callbackMethod", name: NSApplicationWillResignActiveNotification, object: NSApplication.sharedApplication()) } }
130. class MyClass : NSObject { func callbackMethod(with notification: NSNotification){} func setNotification() { let center = NSNotificationCenter.defaultCenter() center .addObserver(self, selector: "callbackMethod", name: NSApplicationWillResignActiveNotification, object: NSApplication.sharedApplication()) } }
131. class MyClass : NSObject { func callbackMethod(with notification: NSNotification){} func setNotification() { let center = NSNotificationCenter.defaultCenter() center .addObserver(self, selector: "callbackMethod", name: NSApplicationWillResignActiveNotification, object: NSApplication.sharedApplication()) } }
132. class MyClass : NSObject { func callbackMethod(with notification: NSNotification){} func setNotification() { let center = NSNotificationCenter.defaultCenter() center .addObserver(self, selector: #selector(callbackMethod), name: NSApplicationWillResignActiveNotification, object: NSApplication.sharedApplication()) } }
133. class MyClass : NSObject { func callbackMethod(with notification: NSNotification){} func setNotification() { let center = NSNotificationCenter.defaultCenter() center .addObserver(self, selector: #selector(MyClass.callbackMethod), name: NSApplicationWillResignActiveNotification, object: NSApplication.sharedApplication()) } }
134. class MyClass : NSObject { func callbackMethod(){} func callbackMethod(with notification: NSNotification){} func setNotification() { let center = NSNotificationCenter.defaultCenter() center .addObserver(self, selector: #selector(MyClass.callbackMethod), name: NSApplicationWillResignActiveNotification, object: NSApplication.sharedApplication()) } }
135. class MyClass : NSObject { func callbackMethod(){} func callbackMethod(with notification: NSNotification){} func setNotification() { let center = NSNotificationCenter.defaultCenter() center .addObserver(self, selector: #selector(MyClass.callbackMethod), name: NSApplicationWillResignActiveNotification, object: NSApplication.sharedApplication()) } }
136. class MyClass : NSObject { func callbackMethod(){} func callbackMethod(with notification: NSNotification){} func setNotification() { let center = NSNotificationCenter.defaultCenter() center .addObserver(self, selector: #selector(MyClass.callbackMethod(with:)), name: NSApplicationWillResignActiveNotification, object: NSApplication.sharedApplication()) } }
137. 0033 - Import Obj-C constants as Swift types
138. HK_EXTERN NSString * const HKQuantityTypeIdentifierBodyMassIndex; HK_EXTERN NSString * const HKQuantityTypeIdentifierBodyFatPercentage; HK_EXTERN NSString * const HKQuantityTypeIdentifierHeight; HK_EXTERN NSString * const HKQuantityTypeIdentifierBodyMass; HK_EXTERN NSString * const HKQuantityTypeIdentifierLeanBodyMass;
139. HK_EXTERN NSString * const HKQuantityTypeIdentifierBodyMassIndex; HK_EXTERN NSString * const HKQuantityTypeIdentifierBodyFatPercentage; HK_EXTERN NSString * const HKQuantityTypeIdentifierHeight; HK_EXTERN NSString * const HKQuantityTypeIdentifierBodyMass; HK_EXTERN NSString * const HKQuantityTypeIdentifierLeanBodyMass;
140. enum HKQuantityTypeIdentifier : String { case BodyMassIndex case BodyFatPercentage case Height case BodyMass case LeanBodyMass }
141. enum HKQuantityTypeIdentifier : String { case BodyMassIndex case BodyFatPercentage case Height case BodyMass case LeanBodyMass }
142. HK_EXTERN NSString * const HKQuantityTypeIdentifierBodyMassIndex; HK_EXTERN NSString * const HKQuantityTypeIdentifierBodyFatPercentage; HK_EXTERN NSString * const HKQuantityTypeIdentifierHeight; HK_EXTERN NSString * const HKQuantityTypeIdentifierBodyMass; HK_EXTERN NSString * const HKQuantityTypeIdentifierLeanBodyMass;
143. enum HKQuantityTypeIdentifier : String { case BodyMassIndex case BodyFatPercentage case Height case BodyMass case LeanBodyMass }
144. enum HKQuantityTypeIdentifier : String { case BodyMassIndex case BodyFatPercentage case Height case BodyMass case LeanBodyMass }
145. 0005 - Better translation of Obj-C APIs into Swift
146. let color = NSColor.blueColor()
147. let color = NSColor.blueColor()
148. let color = NSColor.blueColor() Prune redundant type names
149. let color = NSColor.blue()
150. rootViewController .presentViewController(alert, animated: true, completion: nil)
151. rootViewController .presentViewController(alert, animated: true, completion: nil) Add default arguments
152. rootViewController .presentViewController(alert, animated: true, completion: nil) Nullable trailing closures default = nil
153. rootViewController .presentViewController(alert, animated: true)
154. rootViewController .presentViewController(alert, animated: true) Shouldn't animated default = true
155. rootViewController.presentViewController(alert)
156. rootViewController.presentViewController(alert) Prune redundant type names
157. rootViewController.present(alert)
158. var empty: Bool
159. var empty: Bool Prepend "is" to Bools
160. var isEmpty: Bool
161. addLineToPoint(myPoint)
162. addLineToPoint(myPoint) func addLineToPoint(_: CGPoint)
163. addLineToPoint(myPoint) func addLineToPoint(_: CGPoint) Add first argument labels
164. addLineToPoint(myPoint) func addLineToPoint(_: CGPoint) Add first argument labels
165. addLine(to: myPoint) func addLine(to point: CGPoint) Add first argument labels
166. addLine(to: myPoint) func addLine(to point: CGPoint) Add first argument labels
167. Add first argument labels
168. Add first argument labels
169. var URLHandler
170. var URLHandler Lower case imported types
171. var urlHandler Lower case imported types
172. enum Currency { case Dollars case Euros case Pounds case Yen } Lower case imported types
173. enum Currency { case Dollars case Euros case Pounds case Yen } Lower case imported types
174. enum Currency { case dollars case euros case pounds case yen } Lower case imported types
175. 0036 - Requiring Leading Dot Prefixes for Enum Instance Member Implementations
176. enum Currency { case dollars case euros case pounds case yen var symbol: String { switch self { case dollars: return "$" default: return "I don't know" } } }
177. enum Currency { case dollars case euros case pounds case yen var symbol: String { switch self { case .dollars: return "$" default: return "I don't know" } } }
178. enum Currency { case dollars case euros case pounds case yen var symbol: String { switch self { case dollars: return "$" default: return "I don't know" } } }
179. enum Currency { case dollars case euros case pounds case yen var symbol: String { switch self { case .dollars: return "$" default: return "I don't know" } } }
180. enum Currency { case dollars case euros case pounds case yen var symbol: String { switch self { case .dollars: return "$" default: return "I don't know" } } }
181. 0043 - Declare variables in 'case' labels with multiple patterns
182. enum MyEnum { case case1(Int,Float) case case2(Float,Int) } switch value { case let .case1(x, 2), let .case2(2, x): print(x) case .case1, .case2: break }
183. enum MyEnum { case case1(Int,Float) case case2(Float,Int) } switch value { case let .case1(x, 2), let .case2(2, x): print(x) case .case1, .case2: break }
184. enum MyEnum { case case1(Int,Float) case case2(Float,Int) } switch value { case let .case1(x, 2), let .case2(2, x): print(x) case .case1, .case2: break }
185. enum MyEnum { case case1(Int,Float) case case2(Float,Int) } switch value { case let .case1(x, 2), let .case2(2, x): print(x) case .case1, .case2: break }
186. enum MyEnum { case case1(Int,Float) case case2(Float,Int) } switch value { case let .case1(x, 2), let .case2(2, x): print(x) case .case1, .case2: break }
187. enum MyEnum { case case1(Int,Float) case case2(Float,Int) } switch value { case let .case1(x, 2), let .case2(2, x): print(x) case .case1, .case2: break }
188. enum MyEnum { case case1(Int,Float) case case2(Float,Int) } switch value { case let .case1(x, 2), let .case2(2, x): print(x) case .case1, .case2: break }
189. 0001 - Allow (most) keywords as argument labels
190. calculateRevenue(for sales: Int, in currency: Currency)
191. calculateRevenue(for sales: Int, in currency: Currency)
192. calculateRevenue(for numberOfCopies, in .dollars)
193. 0009 - Require self for accessing instance members
194. struct Friend { let name: String let location: String func nameBadge() { print("I'm", name, "from", location) } }
195. struct Friend { let name: String let location: String func nameBadge() { print("I'm", name, "from", location) } }
196. struct Friend { let name: String let location: String func nameBadge() { print("I'm", name, "from", location) } }
197. struct Friend { let name: String let location: String func nameBadge() { print("I'm", self.name, "from", self.location) } }
198. struct Friend { let name: String let location: String func nameBadge() { print("I'm", self.name, "from", self.location) } } Require self for accessing instance members REJECTED
199. 0011 - Replace typealias keyword with associatedtype for associated type declarations
200. 0011 - Replace typealias keyword with associatedtype for associated type declarations
201. protocol Prot { typealias Container : SequenceType } extension Prot { typealias Element = Container.Generator.Element }
202. protocol Prot { typealias Container : SequenceType } extension Prot { typealias Element = Container.Generator.Element }
203. protocol Prot { associatedtype Container : SequenceType } extension Prot { typealias Element = Container.Generator.Element }
204. 0092 Typealiases in protocols and protocol extensions
205. protocol Sequence { associatedtype Iterator : IteratorProtocol typealias Element = Iterator.Element }
206. protocol Sequence { associatedtype Iterator : IteratorProtocol typealias Element = Iterator.Element }
207. func sum<T: Sequence where T.Element == Int>(sequence: T) -> Int { return sequence.reduce(0, combine: +) }
208. extension Sequence { typealias Element = Iterator.Element func concat(other: Self) -> [Element] { return Array<Element>(self) + Array<Element>(other) } }
209. extension Sequence { typealias Element = Iterator.Element func concat(other: Self) -> [Element] { return Array<Element>(self) + Array<Element>(other) } }
210. 0048 Generic Type Aliases
211. typealias StringDictionary<T> = Dictionary<String, T> typealias DictionaryOfStrings<T : Hashable> = Dictionary<T, String> typealias IntFunction<T> = (T) -> Int typealias Vec3<T> = (T, T, T) typealias BackwardTriple<T1,T2,T3> = (T3, T2, T1)
212. typealias StringDictionary<T> = Dictionary<String, T> typealias DictionaryOfStrings<T : Hashable> = Dictionary<T, String> typealias IntFunction<T> = (T) -> Int typealias Vec3<T> = (T, T, T) typealias BackwardTriple<T1,T2,T3> = (T3, T2, T1)
213. typealias StringDictionary<T> = Dictionary<String, T> typealias DictionaryOfStrings<T : Hashable> = Dictionary<T, String> typealias IntFunction<T> = (T) -> Int typealias Vec3<T> = (T, T, T) typealias BackwardTriple<T1,T2,T3> = (T3, T2, T1)
214. typealias StringDictionary<T> = Dictionary<String, T> typealias DictionaryOfStrings<T : Hashable> = Dictionary<T, String> typealias IntFunction<T> = (T) -> Int typealias Vec3<T> = (T, T, T) typealias BackwardTriple<T1,T2,T3> = (T3, T2, T1)
215. typealias StringDictionary<T> = Dictionary<String, T> typealias DictionaryOfStrings<T : Hashable> = Dictionary<T, String> typealias IntFunction<T> = (T) -> Int typealias Vec3<T> = (T, T, T) typealias BackwardTriple<T1,T2,T3> = (T3, T2, T1)
216. 0046 Establish consistent label behavior across all parameters including first labels
217. func increase(ourNumber: Int, delta: Int) -> Int { } increase(6, delta: 3)
218. func increase(ourNumber: Int, delta: Int) -> Int { } increase(6, delta: 3)
219. func increase(ourNumber: Int, delta: Int) -> Int { } increase(6, delta: 3)
220. func increase(ourNumber: Int, delta: Int) -> Int { } increase(6, delta: 3)
221. func increase(ourNumber: Int, delta: Int) -> Int { } increase(ourNumber: 6, delta: 3)
222. func increase(_ ourNumber: Int, delta: Int) -> Int { } increase(6, delta: 3)
223. 0023 - Swift API Guidelines
224. Swift API Design Guidelines
225. myArray.sort()
226. sort() sorted()
227. sortInPlace() sort()
228. sort() sorted()
229. sort() sorted() Name functions and methods according to their side-effects
230. x.distance(to: y) i.successor() Those without side-effects should read as noun phrases
231. x.sort() x.append(y) Those with side-effects should read as imperative noun phrases
232. sort() sorted()/sorting() Use the “ed/ing” rule to name the nonmutating counterpart of a mutating method
233. Prefer methods to free functions
234. Prefer methods to free functions Protocol Extensions in Swift 2
235. Prefer methods to free functions Protocol Extensions in Swift 2 Except …
236. min(x, y, z) When there's no obvious self
237. print(x) When the function is an unconstrained generic
238. sin(x) When the function is part of the established domain notation
239. Methods can share a base name
240. Methods can share a base name Good when they do analogous things
241. Methods can share a base name Not good (tableView!) when they don't
242. Choose good parameter names
243. func move(from startingIndex: Int, to endingIndex: Int) Choose good parameter names
244. Take advantage of default values
245. Take advantage of default values func hello(name: String = "World")
246. Take advantage of default values init(name: String, hometown: String? = nil)
247. Prefer to locate parameters with defaults at the end init(name: String, hometown: String? = nil)
248. External Argument Labels func move(from startingIndex: Int, to endingIndex: Int)
249. move(from: here to: there)
250. Argument Labels Exceptions
251. min(number1, number2) Omit labels when arguments can't be distinguished
252. Double(someInt) Omit labels in full width inits
253. Double(_ anInt: someInt) Omit labels in full width inits
254. func move(from startingIndex: Int, to endingIndex: Int) When the preposition applies to the whole
255. func moveTo(x: Int, y: Int) When the preposition applies to the whole
256. x.removeBoxes(having Length: 12) When the preposition applies to the whole
257. Swift 3 focus on source stability
260. Next finish Generics stable ABI
265. Understanding Your Toddler iOSConf 2016 Daniel H Steinberg @dimsumthinking