4XJGUͰ
 ؾ࣋ͪྑ͘։ൃ͢Δ !)FBMUI4XJGU.FFUVQ F[VSB

4XJGUͷදݱྗɺؾ࣋ͪྑ͍ʂʂ

5...2

print(self) • ៸໘༑߳ (ezura) • ޷͖ͳ΋ͷ: protocol, enum • τϥΠϑΥʔτۈ຿ • twitter: @eduraaa

Ұϲ݄΄Ͳલʹ4XJGUѪ޷ձͱ͍͏ษڧձͰ
 ͓࿩͍͍ͤͯͨͩͨ͜͠͞ͱ

https://speakerdeck.com/ezura/swift-falseshi-jie-guan-to-sofalsezhi-xu 4XJGUͷੈք؍ͱͦͷடং 4XJGUͷඪ४ϥΠϒϥϦ ͱͷ஥ྑ͘ͳΓํ

for element in [1, 2, 3] { /* do something */ } [1, 2, 3].forEach { _ in /* do something */ } 1 ... 3 if array.isEmpty { /* do something */ } SequenceType
 (CollectionType) ForwardIndexType BooleanType Comparable IntegerLiteral
 Convertible ArrayLiteral
 Convertible

4XJGUΛܗ࡞Δཁૉɺඪ४ϥΠϒϥϦ ཧղ͢Ε͹ Swift ʹௐ࿨ͨ͠ίʔυΛؾ࣋ͪྑ͘ॻ͚ͦ͏ʂ

෼Ͱඪ४ϥΠϒϥϦͱ༡ΜͰΈΑ͏

5 ͔Β 2 ͷൣғ
 (Range) 5...2

for index in 1...5 { print("\(index) times 5 is \(index * 5)") } let names = ["Anna", "Alex", "Brian", "Jack"] let count = names.count for i in 0..

TUSVDU3BOHF&MFNFOU'PSXBSE*OEFY5ZQF *OU͸'PSXBSE*OEFY5ZQF
 ʹ४ڌ͍ͯ͠ΔͷͰѻ͑ͨ ݫີʹ͸ɺ*OU4JHOFE*OUFHFS5ZQFͰ͢ɻ
 ܧঝؔ܎͸4JHOFE*OUFHFS5ZQF*OUFHFS5ZQF 3BOEPN"DDFTT*OEFY5ZQF#JEJSFDUJPOBM*OEFY5ZQF 'PSXBSE*OEFY5ZQF 1...10 &MFNFOU

Represents a discrete value in a series QSPUPDPM'PSXBSE*OEFY5ZQF Value Value Value … …

Represents a discrete value in a series QSPUPDPM'PSXBSE*OEFY5ZQF 5 6 7 … … Equatable
 +
 func successor() -> Self

ࣗ࡞ͷܕʹ'PSXBSE*OEFY5ZQFΛ
 ४ڌͤ͞Δྫ

enum Week { case Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday } extension Week: ForwardIndexType { // ͜ͷ৔߹ͷ enum ͸ Hashable ʹ҉໧తʹ४ڌ͠·͢ɻ // protocol Hashable : Equatable ͳͷͰ͢Ͱʹ Equatable ʹ४ڌࡁΈͰ͢ɻ func successor() -> Week { switch self { case .Sunday: return .Monday case .Monday: return .Tuesday case .Tuesday: return .Wednesday case .Wednesday: return .Thursday case .Thursday: return .Friday case .Friday: return .Saturday case .Saturday: return self // ऴ୺ } } } 'PSXBSE*OEFY5ZQF ྫ Sunday Monday Tuesday … Saturday 8FFL

enum Week { case Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday } extension Week: ForwardIndexType { // ͜ͷ৔߹ͷ enum ͸ Hashable ʹ҉໧తʹ४ڌ͠·͢ɻ // protocol Hashable : Equatable ͳͷͰ͢Ͱʹ Equatable ʹ४ڌࡁΈͰ͢ɻ func successor() -> Week { switch self { case .Sunday: return .Monday case .Monday: return .Tuesday case .Tuesday: return .Wednesday case .Wednesday: return .Thursday case .Thursday: return .Friday case .Friday: return .Saturday case .Saturday: return self // ऴ୺ } } } Week.Friday == Week.Friday // true (Week.Monday ... .Friday).contains(.Wednesday) // true 'PSXBSE*OEFY5ZQF ྫ

Ұ࿈ͷۭؒͷதͷ཭ࢄ஋ Sunday Monday Tuesday … Saturday ͜ͷੑ࣭Λදݱ͢ΔͨΊͷཁ݅ l࣍ͷ஋Λࣔ͢z

enum Week { case Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday } extension Week: ForwardIndexType { // ͜ͷ৔߹ͷ enum ͸ Hashable ʹ҉໧తʹ४ڌ͠·͢ɻ // protocol Hashable : Equatable ͳͷͰ͢Ͱʹ Equatable ʹ४ڌࡁΈͰ͢ɻ func successor() -> Week { switch self { case .Sunday: return .Monday case .Monday: return .Tuesday case .Tuesday: return .Wednesday case .Wednesday: return .Thursday case .Thursday: return .Friday case .Friday: return .Saturday case .Saturday: return .Sunday // ࠷ॳʹ໭Δ } } } (Week.Saturday ... .Monday).contains(.Sunday) // true 'PSXBSE*OEFY5ZQF ྫ Sunday Monday Tuesday … Saturday

5...2 ͭ͡͸ɻɻ

let loopRange: Range = 5...2 ͭ͡͸ɻɻ ࣗ࡞ͷܕ

let loopRange: Range = LoopIndex(5)...LoopIndex(2) ͭ͡͸ɻɻ ࣗ࡞ͷܕ

let loopRange: Range = ͭ͡͸ɻɻ ࣗ࡞ͷܕ 5...2 extension LoopIndex : IntegerLiteralConvertible ॳظԽ࣌ʹ
 ੔਺ϦςϥϧΛड͚औΕΔ

Conforming types can be initialized with integer literals. QSPUPDPM*OUFHFS-JUFSBM$POWFSUJCMF

struct LoopIndex { let rawValue: Int init(_ rawValue: Int) { self.rawValue = rawValue } } // OK let loopIndex = LoopIndex(1) // ௨ৗ͸Ͱ͖ͳ͍ // error: cannot convert value of type 'Int' to specified type 'LoopIndex' let beforeConform: LoopIndex = 5 -PPQ*OEFY ࣗ࡞ͷܕ

struct LoopIndex { let rawValue: Int init(_ rawValue: Int) { self.rawValue = rawValue } } extension LoopIndex: IntegerLiteralConvertible { init(integerLiteral value: IntegerLiteralType) { self.init(value) } } let loopIndex: LoopIndex = 1 -PPQ*OEFY*OUFHFS-JUFSBM$POWFSUJCMF 0,

struct LoopIndex { let rawValue: Int init(_ rawValue: Int) { self.rawValue = rawValue } } extension LoopIndex: IntegerLiteralConvertible { init(integerLiteral value: IntegerLiteralType) { self.init(value) } } extension LoopIndex: ForwardIndexType { // ུ } let loopIndex: LoopIndex = 1 let loopRange : Range = 5...2 loopRange.contains(1) // true -PPQ*OEFY*OUFHFS-JUFSBM$POWFSUJCMF 0,

let loopRange: Range = 5...2

5...2 ஫τϦοΩʔͳ͜ͱΛ͢Δͱ͖͸৻ॏʹʂʂ

ͪΐͬͱৼΓฦͬͯΈ·͠ΐ͏

QSPUPDPM'PSXBSE*OEFY5ZQF QSPUPDPM*OUFHFS-JUFSBM$POWFSUJCMF

enum Week { case Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday } 8FFL Sunday Monday Tuesday … Saturday 8FFL

enum Week { case Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday } extension Week: ForwardIndexType { // ͜ͷ৔߹ͷ enum ͸ Hashable ʹ҉໧తʹ४ڌ͠·͢ɻ // protocol Hashable : Equatable ͳͷͰ͢Ͱʹ Equatable ʹ४ڌࡁΈͰ͢ɻ func successor() -> Week { switch self { case .Sunday: return .Monday case .Monday: return .Tuesday case .Tuesday: return .Wednesday case .Wednesday: return .Thursday case .Thursday: return .Friday case .Friday: return .Saturday case .Saturday: return self // ऴ୺ } } } 8FFL'PSXBSE*OEFY5ZQF Sunday Monday Tuesday … Saturday 8FFL

struct LoopIndex { let rawValue: Int init(_ rawValue: Int) { self.rawValue = rawValue } } // OK let loopIndex = LoopIndex(1) // ௨ৗ͸Ͱ͖ͳ͍ // error: cannot convert value of type 'Int' to specified type 'LoopIndex' let beforeConform: LoopIndex = 5 -PPQ*OEFY ࣗ࡞ͷܕ

struct LoopIndex { let rawValue: Int init(_ rawValue: Int) { self.rawValue = rawValue } } extension LoopIndex: IntegerLiteralConvertible { init(integerLiteral value: IntegerLiteralType) { self.init(value) } } let loopIndex: LoopIndex = 1 -PPQ*OEFY*OUFHFS-JUFSBM$POWFSUJCMF -PPQ*OEFY 1

struct LoopIndex { let rawValue: Int init(_ rawValue: Int) { self.rawValue = rawValue } } extension LoopIndex: IntegerLiteralConvertible { init(integerLiteral value: IntegerLiteralType) { self.init(value) } } let loopIndex: LoopIndex = 1 -PPQ*OEFY*OUFHFS-JUFSBM$POWFSUJCMF -PPQ*OEFY 1

⭕࢖͑Δػೳ͕૿͑Δ

΋ͬͱخ͍͜͠ͱ

ϓϩτίϧʹ४ڌ͢Δ͜ͱͰ
 ܕ͕ද֓͢೦ΛΑΓ໌֬ʹදݱͰ͖Δʂ

enum Week { case Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday } extension Week: ForwardIndexType { // ͜ͷ৔߹ͷ enum ͸ Hashable ʹ҉໧తʹ४ڌ͠·͢ɻ // protocol Hashable : Equatable ͳͷͰ͢Ͱʹ Equatable ʹ४ڌࡁΈͰ͢ɻ func successor() -> Week { switch self { case .Sunday: return .Monday case .Monday: return .Tuesday case .Tuesday: return .Wednesday case .Wednesday: return .Thursday case .Thursday: return .Friday case .Friday: return .Saturday case .Saturday: return self // ऴ୺ } } } 8FFL'PSXBSE*OEFY5ZQF Sunday Monday Tuesday … Saturday 8FFL

struct LoopIndex { let rawValue: Int init(_ rawValue: Int) { self.rawValue = rawValue } } extension LoopIndex: IntegerLiteralConvertible { init(integerLiteral value: IntegerLiteralType) { self.init(value) } } let loopIndex: LoopIndex = 1 -PPQ*OEFY*OUFHFS-JUFSBM$POWFSUJCMF -PPQ*OEFY 1

͝ਗ਼ௌ͋Γ͕ͱ͏͍͟͝·ͨ͠

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