Swift

Swift has some of the best features of other languages. These are my thoughts on that after my initial review of the language.

Transcript

1. swift @<your company>
2. agenda
3. agenda interesting language features when will we start using swift here? should we do this again?
4. swift only plays the hits
6. enumeration and tuples
7. for i, v in enumerate(['tic', 'tac', ‘toe’]): print i, v https://docs.python.org/2/tutorial/datastructures.html#looping-techniques
8. for (index, item) in enumerate([“tic”, “tac”, “toe”]) { println(“\(index) : \(item)”) }
10. C# style generics
11. void Swap<T>(ref T lhs, ref T rhs) { T temp = lhs; lhs = rhs; rhs = temp; } http://msdn.microsoft.com/en-us/library/twcad0zb.aspx
12. func swap<T>(inout lhs: T, inout rhs: T) { let temp = a a = b b = temp } https://developer.apple.com/library/prerelease/ios/documentation/swift/conceptual/swift_programming_language/Generics.html
13. T is inferred to be int and string correctly: ! var someInt = 3 var anotherInt = 107 swap(&someInt, &anotherInt) // someInt is now 107, and anotherInt is now 3 var someString = "hello" var anotherString = "world" swap(&someString, &anotherString) // someString is now "world", // and anotherString is now "hello"
14. ! var gameOptions = [“tic”, “tac”, “toe”] ! for (index, item) in enumerate(gameOptions) { println(“\(index) : \(item)”) } generics in collections
15. generics in collections ! var gameOptions:String[] = [“tic”, “tac”, “toe”] ! for (index, item) in enumerate(gameOptions) { println(“\(index) : \(item)”) }
16. generics in collections ! var gameOptions:String[] = [“tic”, “tac”, 42] ! for (index, item) in enumerate(gameOptions) { println(“\(index) : \(item)”) }
17. other familiar things from C# (and other languages)
18. override
19. public override int Area() { return side * side; } http://msdn.microsoft.com/en-us/library/ebca9ah3.aspx
20. // this class is twice a big! override func area() -> Int { return side * side * 2; } https://developer.apple.com/library/prerelease/ios/documentation/swift/conceptual/swift_programming_language/Inheritance.html
21. nullable types
22. // C# int? i = null; ! // swift var i:Int? = nil
23. why “optionals” aka “nullable types”?
24. optionals can be evaluated as bools (LogicValue) in conditionals var i:Int? = nil if (i) { println(“thank god for logic values”) }
25. swift is also like objective-c
26. ARC, blocks, closures, retain cycles!!!
27. // objective-c view controller @property (strong, nonatomic) AAsyncLib *awesomeAsyncLib; ! - (IBAction)awesomeButtonPressed:(id)sender { [self.awesomeAsyncLib doIt:^(NSString *result) { [self showResult:result]; }]; }
28. retain cycle!
29. // objective-c view controller @property (strong, nonatomic) AAsyncLib *awesomeAsyncLib; ! - (IBAction)awesomeButtonPressed:(id)sender { // remember to avoid retain cycle __weak typeof(self)weakSelf = self; ! [self.awesomeAsyncLib doIt:^(NSString *result) { [weakSelf showResult:result]; }]; }
30. // objective-c view controller var awesomeAsyncLib: AAsyncLib ! @IBAction func awesomeButtonPressed:(sender: NSButton) { awesomeAsyncLib.doIt() { // use capture list to avoid retain cycle // use unowned if value can never be nil // use weak if value can possibly be nil (if you need // to check for existence) [unowned self](result: NSString) in [self.showResult(result)]; } } https://developer.apple.com/library/prerelease/ios/documentation/swift/conceptual/swift_programming_language/ AutomaticReferenceCounting.html
31. resources ! hacker news: https://hn.algolia.com/?q=swift#!/story/forever/0/swift ! code migration: https://developer.apple.com/library/prerelease/ios/documentation/swift/conceptual/ buildingcocoaapps/Migration.html ! objc interop: https://developer.apple.com/library/prerelease/ios/documentation/swift/conceptual/ buildingcocoaapps/InteractingWithObjective-CAPIs.html#//apple_ref/doc/uid/TP40014216-CH4-XID_26 ! example app: https://developer.apple.com/library/prerelease/ios/samplecode/Lister-Swift/Introduction/ Intro.html