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Value Types͔ΒݟΔWWDC16
ɹ
WWDC16. Meetup @Wantedly with ܦ৽ฉࣾ
2016/06/30
@shingt iOS / Rails Engineer @ Wantedly, Inc.
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Value Types
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WWDC 2016
→ Protocol and Value Oriented Programming in UIKit
Apps
→ What's New in Foundation for Swift
→ Understanding Swift Performance
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Agenda
* MVCΞϓϦέʔγϣϯʹ͓͚ΔValue Types
* `Protocol and Value Oriented Programming in
UIKit Apps` ΑΓ
* Swift 3ͰՃ͞ΕΔFoundationͷValue Typesʹ͍ͭͯ
* `What's New in Foundation for Swift` ΑΓ
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MVCΞϓϦέʔγϣϯʹ͓͚ΔValue Types
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WWDC 2015
→ Protocol-Oriented Programming in Swift
→ Building Better Apps with Value Types in Swift
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WWDC 2016
Protocol and Value Oriented Programming in UIKit
Apps
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Value Types in MVC-based Application
* Model => ʢ͑ΔॴͰʣͬͯવʢUncontroversialʣ
* View => ?ɹ
* Controller => ? ɹ
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Value Types in MVC-based Application
* Model => ʢ͑ΔॴͰʣͬͯવʢUncontroversialʣ
* View
* StructͰͷϨΠΞτॲཧ <= ࠓհ͠·͢
* ΄͔
* Controller => ? ɹ
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https://developer.apple.com/library/prerelease/
content/LucidDreams
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class DecoratingLayoutCell : UITableViewCell {
var content: UIView
var decoration: UIView
}
// => UIViewʹద༻Ͱ͖ͳ͍
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// CellͱUIViewͷͲͪΒʹద༻Ͱ͖ΔܗͰఆٛ
struct DecoratingLayout {
var content: UIView
var decoration: UIView
mutating func layout(in rect: CGRect) {
content.frame = ...
decoration.frame = ...
}
}
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class DreamCell : UITableViewCell {
override func layoutSubviews() {
// DecoratingLayoutʹΑΓlayout
var decoratingLayout = DecoratingLayout(
content: content, decoration: decoration)
decoratingLayout.layout(in: bounds)
}
}
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struct DecoratingLayout {
// contentͱdecorationΛಉ͡ܕʹ͢ΔͨΊͷ੍ΛGenericsͰ
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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ViewΛΈ߹ΘͤΔʁ
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Composition of Views
"Minimize the number of views that we use."ɹɹ
ʢViewͷੜίετߴͳͷͰʣ
=> Composition of Values
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Composition of values
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Composition of values
struct CascadingLayout {
// Layoutʹద߹ͨ͠ܕͷྻ
var children: [Child]
mutating func layout(in rect: CGRect) {...}
}
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struct MultiPaneLayout<...>: Layout {
mutating func layout(in rect: CGRect) {
// CascadingLayoutͱDecoratingLayoutΛΈ߹ΘͤΔ
let decoration = CascadingLayout(children: accessories)
var composedLayout = DecoratingLayout(
content: content, decoration: decoration)
// ࠷ऴతͳϨΠΞτॲཧ
composedLayout.layout(in: rect)
}
}
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ηογϣϯͰ͜͜·Ͱ
=> αϯϓϧίʔυΛ͘ͱ
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؆қ·ͱΊ
* Viewɹ
* StructΛͬͨϨΠΞτॲཧ
* Value TypesʹΑΔComposition
* Controllerʢলུʣ
* Single code pathɹ
* EnumͰͷঢ়ଶཧ
* શମͱͯ͠Local ReasoningʢہॴਪʣՄೳͳίʔυ
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Swift 3ͰՃ͞ΕΔFoundationͷ
Value Typesʹ͍ͭͯ
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→ What's New in Foundation for Swift
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0069-swift-mutability-for-foundation.md
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Swift 3ͰͷFoundationͷมԽ
* FoundationͷҰ෦ͷReference TypesΛϥοϓ͢ΔValue Types͕Ճ
* ྫ: NSDate => Date
* "mutability when you need it"ɹ
* ඪ४ϥΠϒϥϦͷprotocolͷ४ڌ
* ྫ: Equatable, Comparable, ...
* ܕηʔϑͷՕॴ͕૿͑Δ
* NSϓϨϑΟΫε͕औΕΔʢ͜Εผͷproposalʣ
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Ұ෦
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ྫ: Date
public struct Date :
ReferenceConvertible,
Comparable,
Equatable,
CustomStringConvertible {
...
}
// Comparable
public func <(lhs: Date, rhs: Date) -> Bool {
return lhs.timeIntervalSinceReferenceDate
< rhs.timeIntervalSinceReferenceDate
}
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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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ηογϣϯதͷଞͷ
* ͦͷଞͷ֤छAPIͷมߋ༰
* SwiftͱObjective-CؒͷBridging
* Swift 3༻APIͷMigration
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ͱ͜ΖͰValue Types
* ͲͷΑ͏ͳ࣌ʹར༻͖͢ͳͷ͔ʁ
* ͦͷ࣌ͳͥύϑΥʔϚϯε͕ྑ͍ͷ͔ʁ
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→ Understanding Swift Performance (WWDC 16)
→ Optimizing Swift Performance (WWDC 15)
* Memory allocation
* Reference counting
* Method dispatch
ͳͲͷ؍͔Β෦࣮ަ͑ͯղઆ
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Summary
* WWDC 16ͰͷValue Typesʹؔͯ͠ͷΛհ͠·ͨ͠
* MVCΞϓϦέʔγϣϯʹ͓͚ΔValue Typesͷར༻
* StructͷCompositionͰLayoutΛදݱ͢Δྫͷհ
* Swift 3ͰՃ͞ΕΔFoundationͷValue Typesʹ͍ͭͯ
* Dateͷྫͷհ
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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