Value Types in WWDC16

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

11. None
12. None

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) } }
16. None

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 {...}
18. None

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

25. None

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