Swift 中級編

1.Objective-Cを愛する人のためのSwift
2.Swift小ネタ集

Transcript

1. Swift தڃฤ Nishiyama Yusei (@yuseinishiyama) Swift LT at Yahoo! JAPAN 2014/6/25
2. ࣗݾ঺հ • iOSΞϓϦέʔγϣϯ։ൃऀ • Unity΋গʑ • ࠷ۙ͸OpenCVɺػցֶशͷษڧΛ͍ͯ͠Δ͕਺ֶ͕ΞϨͳͷͰΞϨ • WWDC2014ؔ࿈͸ɺMetalΛ͸͡Ίͱͨ͠GPUपΓΛ௥͍͖͍ͬͯͨ name:Nishiyama Yusei twitter:@yuseinishiyamaɹ github:yuseinishiyama blog:http://yuseinishiyama.com
3. Ϡό͍ Swift৘ใग़ਚͯ͘͠Δײ͕͋Δ ˞·ͱΊ͍͖ͯͨͩ͋Γ͕ͱ͏͍͟͝·͢ɻ
 େมॏๅ͓ͯ͠Γ·͢ɻ
4. ͱΓ͋͑ͣυΩϡϝϯτ
 શ෦ಡΜͰχονͳ৘ใ୳ͦ͏… l4XJGU
   1SPHSBNNJOH
   -BOHVBHFz l6TJOH
   4XJGU
   8JUI
   $PDPB
   BOE
   0CKFDUJWF$z
5. ಡΜͰؾ͍ͮͨ
6. ࢲ͸Objective-C͕େ޷͖Ͱ͢
7. Objective-CΛ
 Ѫ͢ΔਓͷͨΊͷSwift ୈҰ෦
8. ᷿ͷ੠ • Objective-C͸௵͕͠ޮ͔ͳ͍ɻ • Objective-CͷγϯλοΫε͸ฅɻ • SwiftͰObjective-C͔Βղ์͞Εͨɻ • []←͜Ε͕ੜཧతʹແཧɻ • ((()(())))←͜Ε͸େ޷͖͚ͩͲͶʂ
9. Ұํɺࢲ͸…
10. ফ͑ͳ͍Objective-C΁ͷѪ ⾢PCKD@NTH4FOEͷ༐࢟ͱ
 $16ͷ׻ت ࠨਤ ϝοηʔδૹ৴ ಈతଋറ /&9545&1 ๛෋ͳ࣮ߦ࣌৘ใ *.1
11. Swiftʹ
 Objective-Cͷ໘ӨΛ୳͢ຖ೔…
12. ௒ઈ͍ͱ͓͍͠idܕ typedef struct objc_object { class isa; } *id; ! // ͔Θ͍͍...
13. ʮUsing Swift with Cocoa and Objective-Cʯ ΑΓ “Swift imports id as AnyObject.”
14. ͍ͨʂʂ
15. ࢖ͬͯΈΔ // ద౰ͳؔ਺Λએݴͯ͠... func someFunc() { return } ! // idܕ૬౰ͷΦϒδΣΫτΛએݴͯ͠... var anyObj : AnyObject ! // ίϯύΠϧ͸௨Δ͸ͣ... anyObj.someFunc()
16. 'AnyObject' does not have a member named 'someFunc()'
 
 ίϯύΠϧͰ͖ͳ͍…
17. ͜Μͳͷidܕ͡Όͳ͍ʂʂ
18. υΩϡϝϯτͷαϯϓϧίʔυ var myObject: AnyObject myObject = NSDate() myObject.characterAtIndex(5) // crash, myObject does't respond to that method” ! // υΩϡϝϯτͰ͸࣮ߦ࣌ΤϥʔʹͳΔͱॻ͍ͯ͋Δɻ
19. ΋͏গ͠ௐ΂ͯΈΔ • You can also call any Objective-C method and access any property without casting to a more specific class type. This includes Objective-C compatible methods marked with the @objc attribute. • @objcଐੑ͕͍ͭͨɺObjective-Cޓ׵ͷϝ ιουͰͳ͍ͱ͍͚ͳ͍Β͍͠ɻ
20. ͞Βʹ… • When you define a Swift class that inherits from NSObject or any other Objective-C class, the class is automatically compatible with Objective-C. • Ͳ͏΍ΒObjective-CͷΫϥεΛܧঝͨ͠SwiftͷΫ ϥε͸ࣗಈతʹObjective-Cޓ׵ʹͳΔΒ͍͠ɻ • ͖ͬ͞ͷྫͰݺͼग़͍ͯͨ͠characterAtIndex͸ Objective-Cͷϝιου͔ͩΒಈతʹݺͼग़ͤͨɻ
21. ؾΛऔΓ௚ͯ͠ // Objective-Cޓ׵ͷΫϥεɻ @objc class SomeClass { func someFunc() { return } } ! // AnyObjectʹIntܕͷ஋Λ୅ೖɻ var anyObj : AnyObject = 1 ! // ࣮૷͞Ε͍ͯͳ͍ϝιουͷݺͼग़͠... anyObj.someFunc()
22. -[__NSCFNumber someFunc]: unrecognized selector sent to instance 0x137
23. unrecognized selector
24. ͜ͷ੠͸…
25. idܕͩʂʂʂʂ
26. Selector΋୳͢ let mySEL: Selector = “someFunc" ! // ஫ҙ: Playground্ͩͱΫϥογϡ͢Δɻ
    ! // ※ίϚϯυϥΠϯ͔ΒͷREPLͩͱେৎ෉ɻ
27. ิ଍:
 จࣈྻޓ׵ʹ͢Δϓϩτίϧ // Selector͸ҎԼͷϓϩτίϧʹదԠ͍ͯ͠ΔͷͰɺ // จࣈྻ͔ΒॳظԽͰ͖Δɻ
    protocol StringLiteralConvertible : ExtendedGraphemeClusterLiteralConvertible { typealias StringLiteralType class func convertFromStringLiteral(value: StringLiteralType) -> Self } ! protocol ExtendedGraphemeClusterLiteralConvertible { typealias ExtendedGraphemeClusterLiteralType class func convertFromExtendedGraphemeClusterLiteral(value: ExtendedGraphemeClusterLiteralType) -> Self }
28. Target-Actionύλʔϯ͸݈ࡏ class UIResponder : NSObject { . . . func canPerformAction(action: Selector, withSender sender: AnyObject!) -> Bool // Allows an action to be forwarded to another target. By default checks - canPerformAction:withSender: to either return self, or go up the responder chain. func targetForAction(action: Selector, withSender sender: AnyObject!) -> AnyObject! . . . }
29. ݁࿦ • SwiftͰ΋ಈతͳίʔυ͕͔͚Δɻ • ͱ͸͍͏΋ͷͷɺ݁ہͷͱ͜ΖObjective-CΛ ͔·͍ͯ͠Δ͚ͩɻ • Objective-Cͱͷ࿈ܞΛߟ͑ͳ͍ݶΓɺ
 ੵۃతʹ࢖༻͢Δ΂͖͸ͳͦ͞͏ɻ
30. ͦ΋ͦ΋ɺϝιουͷಈతݺͼग़͠ΛࣙΊ͔ͨΒ
 ߴ଎Խͨ͠ʹҧ͍ͳ͍…
 (੩తʹ͢Ε͹LLVMʹΑΔ࠷దԽͷϝϦοτ΋ड͚Εͦ͏)
31. ωλ੾Ε
 Swiftখωλू ୈೋ෦
32. Special Literals • __FILE__
 ݱࡏͷϑΝΠϧ໊ • __LINE__
 ݱࡏͷߦ਺ • __COLUMN__
 ݱࡏͷྻ਺ • __FUNCTION__
 ࣮ߦதͷؔ਺໊
33. REPLͰ΍Δͱ __FILE__ // => “<REPL>" ! __FUNCTION__// => "$__lldb_expr"
34. ΧϦʔԽͱ෦෼ద༻
35. http://ja.wikipedia.org/wiki/ΧϦʔԽ “ΧϦʔԽ (currying) ͱ͸ɺܭࢉػՊֶ෼ ໺ͷٕ๏ͷҰͭɻෳ਺ͷҾ਺ΛͱΔؔ਺ ΛɺҾ਺͕ʮ΋ͱͷؔ਺ͷ࠷ॳͷҾ਺ʯ Ͱ໭Γ஋͕ʮ΋ͱͷؔ਺ͷ࢒ΓͷҾ਺Λ औΓ݁ՌΛฦؔ͢਺ʯͰ͋ΔΑ͏ͳؔ਺ ʹ͢Δ͜ͱɻ”
36. HaskellɺMLͷΑ͏ʹσϑΥϧτ ͰΧϦʔԽ͞ΕΔΘ͚Ͱ͸ͳ͍ func addTwoNumbers(a: Int, b: Int) -> Int { return a + b } ! var partial = addTwoNumbers(4) ! // ίϯύΠϧΤϥʔ
37. ͜͏ॻ͚͹෦෼ద༻Ͱ͖Δʂ func addTwoNumbers(a: Int)(b: Int) -> Int { return a + b } ! var partial = addTwoNumbers(4) // => (b: Int) -> Int ! var reuslt = partial(b: 5) // => 9
38. Preprocessor Directive • in Swift you use a global constant instead.
 
 ϓϦϓϩηοαͰ͸ͳ͘ɺάϩʔόϧఆ਺Λ࢖͏ɻ • Complex macros are used in C and Objective-C but have no counterpart in Swift.
 
 ؔ਺ܗࣜͷϚΫϩʹ͋ͨΔΑ͏ͳ΋ͷ͸ଘࡏ͠ͳ ͍ɻ
39. ϝιουͷ໋໊ن໿
40. ૢ࡞ʴલஔࢺελΠϧ͸
 ౿ऻ͞ΕΔ໛༷ class myCounter { func incrementBy(amout: Int, numberOfTimes: Int) { // increment } } ! let counter = myCounter() ! // σϑΥϧτͰ͸ɺୈҰҾ਺ͷ֎෦Ҿ਺໊͸লུ͞ΕΔɻ counter.incrementBy(1, numberOfTimes:1)
41. ୈೋҾ਺Ҏ߱΋
 Ҿ਺໊Λলུ͍ͨ͠৔߹ class myCounter { // ΞϯμʔείΞͰΦʔόʔϥΠυͯ͠͠·͏ɻ func incrementBy(amout: Int, _ numberOfTimes: Int) { // increment } } ! let counter = myCounter() ! counter.incrementBy(1, 1)
42. Overflowͷѻ͍ • SwiftͷσϑΥϧτͷڍಈͰ͸Φʔόʔϑϩʔ ͨ͠৔߹Τϥʔ͕ൃੜ͢Δɻ • ΦʔόϑϩʔΛڐ༰͢Δ৔߹ɺ
 Ξϯύαϯυ(&)͔Β࢝·Δࢉज़ԋࢉࢠΛ࢖༻ ͢Δඞཁ͕͋Δɻ • &+, &-, &*, &/, &% ←͍ͭ͜Β
43. ݺͼग़͠ݩʹؼͬͯ͜ͳ͍
 ؔ਺ͷએݴ ! @noreturn func tryMe() { exit(EXIT_FAILURE) } ! // ΋ͪΖΜexitࣗମ΋@noreturn
    @noreturn func exit(_: CInt)
44. ·ͱΊ
45. ܕਪ࿦෇͖ͷ੩తܕ෇͚ݴޠ Swift࠷ߴʂʂʂ(৸ฦΔ)
46. ͋Γ͕ͱ͏͍͟͝·ͨ͠