Swift 1.2 The long-awaited language updates

Presented at Cocoa勉強会関西 #61

Transcript

1. Swift 1.2 5IF
   MPOHBXBJUFE
   MBOHVBHF
   VQEBUFT
2. cockscomb
4. Swift 1.2 5IF
   MPOHBXBJUFE
   MBOHVBHF
   VQEBUFT
5. if let
6. let condition = true let aNumber: Int? = 3 let anotherNumber: Int? = 7 if condition { if let a = aNumber { if let b = anotherNumber { if a < b { println(a + b) } } } } Swift 1.1
7. let condition = true let aNumber: Int? = 3 let anotherNumber: Int? = 7 if condition, let a = aNumber, let b = anotherNumber where a < b { println(a + b) } Swift 1.2
8. let constant must be initialized before use
9. let hour = NSCalendar.currentCalendar() .component(.CalendarUnitHour, fromDate: NSDate()) var meridiem: String if hour < 12 { meridiem = "AM" } else { meridiem = "PM" } println(meridiem) Swift 1.1
10. let hour = NSCalendar.currentCalendar() .component(.CalendarUnitHour, fromDate: NSDate()) let meridiem: String if hour < 12 { meridiem = "AM" } else { meridiem = "PM" } println(meridiem) Swift 1.2
11. Set
12. let abc: NSSet = NSSet(objects: "A", "B", "C") if NSSet(objects: "A").isSubsetOfSet(abc) { println(abc) } Swift 1.1
13. let abc: Set<String> = ["A", "B", "C"] if abc.isSupersetOf(["A"]) { println(abc) } Swift 1.2
14. Static methods and properties
15. class StaticPropertiesAndMethods { static func printDate() { println(date) } static let date = NSDate() } StaticPropertiesAndMethods.printDate() // => "2015-04-10 07:01:00 +0000" Swift 1.2
16. Non-Void return types in Void contexts
17. let wantsVoid: (() -> Void) = { "non-Void here" return } Swift 1.1
18. let wantsVoid: (() -> Void) = { "non-Void here" } Swift 1.2
19. zip
20. let ordinals = ["first", "second", "third"] let values = [1, 2, 3] var ordinalsDict: [String: Int] = [:] for (number, key) in enumerate(ordinals) { if number < values.count { ordinalsDict[key] = values[number] } } println(ordinalsDict) // => ["first": 1, "second": 2, "third": 3] Swift 1.1
21. let ordinals = ["first", "second", "third"] let values = [1, 2, 3] var ordinalsDict: [String: Int] = [:] for (key, value) in zip(ordinals, values) { ordinalsDict[key] = value } println(ordinalsDict) // => ["first": 1, "second": 2, "third": 3] Swift 1.2
22. Type casting
23. let any: AnyObject = 3 let number: Int = any as Int @objc protocol SomeProtocol { func something() -> String } class SomeClass: SomeProtocol { func something() -> String { return "Something awesome" } } let some: AnyObject = SomeClass() if some is SomeProtocol { println((some as SomeProtocol).something()) } Swift 1.1
24. let any: AnyObject = 3 let number: Int = any as! Int protocol SomeProtocol { func something() -> String } class SomeClass: SomeProtocol { func something() -> String { return "Something awesome" } } let some: AnyObject = SomeClass() if some is SomeProtocol { println((some as! SomeProtocol).something()) } Swift 1.2
25. @noescape
26. class Prefix { let string: String let prefix: String? init(string: String, prefix: String? = nil) { self.string = string self.prefix = prefix } func perform() -> String { return prefix.map { $0 + self.string } ?? string } } println(Prefix(string: "String", prefix: "NS").perform()) // => "NSString" println(Prefix(string: "String").perform()) // => "String" Swift 1.1
27. class Prefix { let string: String let prefix: String? init(string: String, prefix: String? = nil) { self.string = string self.prefix = prefix } func perform() -> String { return prefix.map { $0 + string } ?? string } } println(Prefix(string: "String", prefix: "NS").perform()) // => "NSString" println(Prefix(string: "String").perform()) // => "String" Swift 1.2
28. enum Optional<T> : Reflectable, NilLiteralConvertible { case None case Some(T) func map<U>(f: @noescape (T) -> U) -> U? } Swift 1.2
29. @autoclosure assert(someProperty != nil) @autoclosure(escaping) assert(self.someProperty != nil)
30. flatMap
31. let mapped = ["A B C", "D E", "F"].map { $0.componentsSeparatedByString(" ") } println(mapped) // => [[A, B, C], [D, E], [F]] let flatMapped = ["A B C", "D E", "F"].flatMap { $0.componentsSeparatedByString(" ") } println(flatMapped) // => [A, B, C, D, E, F] Swift 1.2
32. func toInt(value: String) -> Int? { return value.toInt() } let one: String? = "1" let mapOne = one.map { toInt($0) } println(mapOne) // => Optional(Optional(1)) let flatMapOne = one.flatMap { toInt($0) } println(flatMapOne) // => Optional(1) Swift 1.2
33. NSEnumerator.generate() -> NSFastGenerator
34. let fonts = "/System/Library/Fonts" let files = NSFileManager() .enumeratorAtPath(fonts)! while let path: AnyObject = files.nextObject() { println(path) } Swift 1.1
35. let fonts = "/System/Library/Fonts" let files = NSFileManager() .enumeratorAtPath(fonts)! for path in files { println(path) } Swift 1.2
36. Others
37. Breaking changes • as as? as! • Remove implicit conversions from NSString/ NSArray/NSDictionary to String/Array/ Dictionary • countElements → count
38. Performances • Tools • Incremental build • Type checker • Swift • Improved many cases • Whole Module Optimization
39. Objective-C • Nullability • nullable • nonnull • NS_ASSUME_NONNULL_BEGIN, NS_ASSUME_NONNULL_END
40. The future has come
41. What’s next?