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.
   

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2. Value Types
   

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3. WWDC 2016
   → Protocol and Value Oriented Programming in UIKit
   Apps
   → What's New in Foundation for Swift
   → Understanding Swift Performance
   

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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
   

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5. MVCΞϓϦέʔγϣϯʹ͓͚ΔValue Types
   

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6. WWDC 2015
   → Protocol-Oriented Programming in Swift
   → Building Better Apps with Value Types in Swift
   

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7. WWDC 2016
   Protocol and Value Oriented Programming in UIKit
   Apps
   

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8. Value Types in MVC-based Application
   * Model => ʢ࢖͑Δ৔ॴͰʣ࢖ͬͯ౰વʢUncontroversialʣ
   * View => ?ɹ
   * Controller => ? ɹ
   

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9. Value Types in MVC-based Application
   * Model => ʢ࢖͑Δ৔ॴͰʣ࢖ͬͯ౰વʢUncontroversialʣ
   * View
   * StructͰͷϨΠΞ΢τॲཧ <= ࠓ೔঺հ͠·͢
   * ΄͔
   * Controller => ? ɹ
   

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10. https://developer.apple.com/library/prerelease/
    content/LucidDreams
    

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13. class DecoratingLayoutCell : UITableViewCell {
    var content: UIView
    var decoration: UIView
    }
    // => UIViewʹ͸ద༻Ͱ͖ͳ͍
    

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14. // CellͱUIViewͷͲͪΒʹ΋ద༻Ͱ͖ΔܗͰఆٛ
    struct DecoratingLayout {
    var content: UIView
    var decoration: UIView
    mutating func layout(in rect: CGRect) {
    content.frame = ...
    decoration.frame = ...
    }
    }
    

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15. class DreamCell : UITableViewCell {
    override func layoutSubviews() {
    // DecoratingLayoutʹΑΓlayout
    var decoratingLayout = DecoratingLayout(
    content: content, decoration: decoration)
    decoratingLayout.layout(in: bounds)
    }
    }
    

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17. struct DecoratingLayout {
    // 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 {...}
    

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19. ViewΛ૊Έ߹ΘͤΔʁ
    

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20. Composition of Views
    "Minimize the number of views that we use."ɹɹ
    ʢViewͷੜ੒͸ίετߴͳͷͰʣ
    => Composition of Values
    

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21. Composition of values
    

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22. Composition of values
    struct CascadingLayout {
    // Layoutʹద߹ͨ͠ܕͷ഑ྻ
    var children: [Child]
    mutating func layout(in rect: CGRect) {...}
    }
    

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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)
    }
    }
    

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24. ηογϣϯͰ͸͜͜·Ͱ
    => αϯϓϧίʔυΛ೷͘ͱ
    

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26. ؆қ·ͱΊ
    * Viewɹ
    * StructΛ࢖ͬͨϨΠΞ΢τॲཧ
    * Value TypesʹΑΔComposition
    * Controllerʢলུʣ
    * Single code pathɹ
    * EnumͰͷঢ়ଶ؅ཧ
    * શମͱͯ͠Local Reasoningʢہॴਪ࿦ʣՄೳͳίʔυ
    

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27. Swift 3Ͱ௥Ճ͞ΕΔFoundation಺ͷ
    Value Typesʹ͍ͭͯ
    

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28. → What's New in Foundation for Swift
    

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29. 0069-swift-mutability-for-foundation.md
    

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30. Swift 3ͰͷFoundationͷมԽ
    * FoundationͷҰ෦ͷReference TypesΛϥοϓ͢ΔValue Types͕௥Ճ
    * ྫ: NSDate => Date
    * "mutability when you need it"ɹ
    * ඪ४ϥΠϒϥϦͷprotocol΁ͷ४ڌ
    * ྫ: Equatable, Comparable, ...
    * ܕηʔϑͷՕॴ͕૿͑Δ
    * NSϓϨϑΟΫε͕औΕΔʢ͜Ε͸ผͷproposalʣ
    

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31. Ұ෦
    

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32. ྫ: Date
    public struct Date :
    ReferenceConvertible,
    Comparable,
    Equatable,
    CustomStringConvertible {
    ...
    }
    // Comparable
    public func Bool {
    return lhs.timeIntervalSinceReferenceDate
    < rhs.timeIntervalSinceReferenceDate
    }
    

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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)
    }
    

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34. ηογϣϯதͷଞͷ࿩୊
    * ͦͷଞͷ֤छAPIͷมߋ಺༰
    * SwiftͱObjective-CؒͷBridging
    * Swift 3༻API΁ͷMigration
    

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35. ͱ͜ΖͰValue Types͸
    * ͲͷΑ͏ͳ࣌ʹར༻͢΂͖ͳͷ͔ʁ
    * ͦͷ࣌ͳͥύϑΥʔϚϯε͕ྑ͍ͷ͔ʁ
    

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36. → Understanding Swift Performance (WWDC 16)
    → Optimizing Swift Performance (WWDC 15)
    * Memory allocation
    * Reference counting
    * Method dispatch
    ͳͲͷ؍఺͔Β಺෦࣮૷΋ަ͑ͯղઆ
    

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37. Summary
    * WWDC 16ͰͷValue Typesʹؔͯ͠ͷ࿩୊Λ঺հ͠·ͨ͠
    * MVCΞϓϦέʔγϣϯʹ͓͚ΔValue Typesͷར༻
    * StructͷCompositionͰLayoutΛදݱ͢Δྫͷ঺հ
    * Swift 3Ͱ௥Ճ͞ΕΔFoundation಺ͷValue Typesʹ͍ͭͯ
    * Dateͷྫͷ঺հ
    

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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
    

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