Value Types in WWDC16

#wwdc16_meetup

Transcript

1. Value Types͔ΒݟΔWWDC16 ɹ WWDC16. Meetup @Wantedly with ೔ܦ৽ฉࣾ 2016/06/30 @shingt iOS / Rails Engineer @ Wantedly, Inc.
2. Value Types
3. WWDC 2016 → Protocol and Value Oriented Programming in UIKit Apps → What's New in Foundation for Swift → Understanding Swift Performance
4. Agenda * MVCΞϓϦέʔγϣϯʹ͓͚ΔValue Types * `Protocol and Value Oriented Programming in UIKit Apps` ΑΓ * Swift 3Ͱ௥Ճ͞ΕΔFoundation಺ͷValue Typesʹ͍ͭͯ * `What's New in Foundation for Swift` ΑΓ
5. MVCΞϓϦέʔγϣϯʹ͓͚ΔValue Types
6. WWDC 2015 → Protocol-Oriented Programming in Swift → Building Better Apps with Value Types in Swift
7. WWDC 2016 Protocol and Value Oriented Programming in UIKit Apps
8. Value Types in MVC-based Application * Model => ʢ࢖͑Δ৔ॴͰʣ࢖ͬͯ౰વʢUncontroversialʣ * View => ?ɹ * Controller => ? ɹ
9. Value Types in MVC-based Application * Model => ʢ࢖͑Δ৔ॴͰʣ࢖ͬͯ౰વʢUncontroversialʣ * View * StructͰͷϨΠΞ΢τॲཧ <= ࠓ೔঺հ͠·͢ * ΄͔ * Controller => ? ɹ
10. https://developer.apple.com/library/prerelease/ content/LucidDreams
13. class DecoratingLayoutCell : UITableViewCell { var content: UIView var decoration: UIView } // => UIViewʹ͸ద༻Ͱ͖ͳ͍
14. // CellͱUIViewͷͲͪΒʹ΋ద༻Ͱ͖ΔܗͰఆٛ struct DecoratingLayout { var content: UIView var decoration: UIView mutating func layout(in rect: CGRect) { content.frame = ... decoration.frame = ... } }
15. class DreamCell : UITableViewCell { override func layoutSubviews() { // DecoratingLayoutʹΑΓlayout var decoratingLayout = DecoratingLayout( content: content, decoration: decoration) decoratingLayout.layout(in: bounds) } }
17. struct DecoratingLayout<Child: Layout> { // contentͱdecorationΛಉ͡ܕʹ͢ΔͨΊͷ੍໿ΛGenericsͰ var content: Child var decoration: Child mutating func layout(in rect: CGRect) { content.frame = ... decoration.frame = ... } } protocol Layout { var frame: CGRect { get set } } extension UIView : Layout {...} extension SKNode : Layout {...}
19. ViewΛ૊Έ߹ΘͤΔʁ
20. Composition of Views "Minimize the number of views that we use."ɹɹ ʢViewͷੜ੒͸ίετߴͳͷͰʣ => Composition of Values
21. Composition of values
22. Composition of values struct CascadingLayout<Child : Layout> { // Layoutʹద߹ͨ͠ܕͷ഑ྻ var children: [Child] mutating func layout(in rect: CGRect) {...} }
23. struct MultiPaneLayout<...>: Layout { mutating func layout(in rect: CGRect) { // CascadingLayoutͱDecoratingLayoutΛ૊Έ߹ΘͤΔ let decoration = CascadingLayout(children: accessories) var composedLayout = DecoratingLayout( content: content, decoration: decoration) // ࠷ऴతͳϨΠΞ΢τॲཧ composedLayout.layout(in: rect) } }
24. ηογϣϯͰ͸͜͜·Ͱ => αϯϓϧίʔυΛ೷͘ͱ
26. ؆қ·ͱΊ * Viewɹ * StructΛ࢖ͬͨϨΠΞ΢τॲཧ * Value TypesʹΑΔComposition * Controllerʢলུʣ * Single code pathɹ * EnumͰͷঢ়ଶ؅ཧ * શମͱͯ͠Local Reasoningʢہॴਪ࿦ʣՄೳͳίʔυ
27. Swift 3Ͱ௥Ճ͞ΕΔFoundation಺ͷ Value Typesʹ͍ͭͯ
28. → What's New in Foundation for Swift
29. 0069-swift-mutability-for-foundation.md
30. Swift 3ͰͷFoundationͷมԽ * FoundationͷҰ෦ͷReference TypesΛϥοϓ͢ΔValue Types͕௥Ճ * ྫ: NSDate => Date * "mutability when you need it"ɹ * ඪ४ϥΠϒϥϦͷprotocol΁ͷ४ڌ * ྫ: Equatable, Comparable, ... * ܕηʔϑͷՕॴ͕૿͑Δ * NSϓϨϑΟΫε͕औΕΔʢ͜Ε͸ผͷproposalʣ
31. Ұ෦
32. ྫ: Date public struct Date : ReferenceConvertible, Comparable, Equatable, CustomStringConvertible { ... } // Comparable public func <(lhs: Date, rhs: Date) -> Bool { return lhs.timeIntervalSinceReferenceDate < rhs.timeIntervalSinceReferenceDate }
33. func whenToLeave() -> Date { ... } let when = whenToLeave().addingTimeInterval(-5.0 * 60.0) // Comparableʹ४ڌ͍ͯ͠ΔͨΊ if Date() < when { // Կؾʹselectorແ͠Ͱهड़Ͱ͖ΔΑ͏ʹͳ͍ͬͯΔTimer timer = Timer(fireDate: when, interval: 0, repeats: false) { print("Almost time to go!") } RunLoop.main.add(timer, forMode: .commonModes) }
34. ηογϣϯதͷଞͷ࿩୊ * ͦͷଞͷ֤छAPIͷมߋ಺༰ * SwiftͱObjective-CؒͷBridging * Swift 3༻API΁ͷMigration
35. ͱ͜ΖͰValue Types͸ * ͲͷΑ͏ͳ࣌ʹར༻͢΂͖ͳͷ͔ʁ * ͦͷ࣌ͳͥύϑΥʔϚϯε͕ྑ͍ͷ͔ʁ
36. → Understanding Swift Performance (WWDC 16) → Optimizing Swift Performance (WWDC 15) * Memory allocation * Reference counting * Method dispatch ͳͲͷ؍఺͔Β಺෦࣮૷΋ަ͑ͯղઆ
37. Summary * WWDC 16ͰͷValue Typesʹؔͯ͠ͷ࿩୊Λ঺հ͠·ͨ͠ * MVCΞϓϦέʔγϣϯʹ͓͚ΔValue Typesͷར༻ * StructͷCompositionͰLayoutΛදݱ͢Δྫͷ঺հ * Swift 3Ͱ௥Ճ͞ΕΔFoundation಺ͷValue Typesʹ͍ͭͯ * Dateͷྫͷ঺հ
38. Reference * Value and Reference Types - Swift Developer Blog * https://developer.apple.com/swift/blog/?id=10 * WWDC 15 * Building Better Apps with Value Types in Swift * https://developer.apple.com/videos/play/wwdc2015/414/ * Protocol-Oriented Programming in Swift * https://developer.apple.com/videos/wwdc/2015/408/ * Optimizing Swift Performance * https://developer.apple.com/videos/play/wwdc2015/409/ * WWDC 16 * Protocol and Value Oriented Programming in UIKit Apps * https://developer.apple.com/videos/play/wwdc2016/419/ * What's New in Foundation for Swift * https://developer.apple.com/videos/play/wwdc2016/207/ * Understanding Swift Performance * https://developer.apple.com/videos/play/wwdc2016/416/ * https://github.com/apple/swift-corelibs-foundation