closures

I am moving my code from Obj. C to Swift C and trying to implementing the Twitter sdk.. But, I am getting an error... Can any body tell me what I have done wrong. Please help me with this. I spent 2 days tried everything but didn't work for me. Your block does not have a return statement, therefore the compiler uses the result of the last statement UIApplication.sharedApplication().openURL(url) as return value, which is a Bool and not Void as declared in the block signature. To solve that problem, just add a return statement: { (url: NSURL, oauthToken: String) -> Void in UIApplication

Can someone explain this error and why this works with closure? If you change 'Test' to 'A' inside 'B' class everything works in both cases. beta 7 protocol Test { func someFunc() -> String var someClosure: () -> Int { get } } class A: Test { func someFunc() -> String { return "A String" } var someClosure: () -> Int { return { return 2 } } } class B { let a: Test let aString: () -> String let aInt: () -> Int init(a: Test){ self.a = a aString = a.someFunc // Error: Partial application of protocol method is not allowed aInt = a.someClosure // Works fine } } UPDATE Also here is my weird

I can create a recursive closure: static IntUnaryOperator fibo; fibo = (i) -> i<2 ? 1 : fibo.applyAsInt(i-1)+ fibo.applyAsInt(i-2); But of course, it has sense only as an example. To be useful, such collection should keep already once counted elements and get() them without recounting. The counting of elements should happen in lazy way, at first need. Thus, no member will have to be calculated more than once. In such way we'll a structure that will look like a recursively defined sequence, and will be fast and reusable. When I started to study Java 8 I thought that Stream works in that way.

Is there a way that one can implicitly declare top-level variables as global for use in closures? For example, if working with code such as this: $a = 0; //A TOP-LEVEL VARIABLE Alpha::create('myAlpha') ->bind(DataSingleton::getInstance() ->query('c') ) ->addBeta('myBeta', function($obj){ $obj->bind(DataSingleton::getInstance() ->query('d') ) ->addGamma('myGamma', function($obj){ $obj->bind(DataSingleton::getInstance() ->query('a') ) ->addDelta('myDelta', function($obj){ $obj->bind(DataSingleton::getInstance() ->query('b') ); }); }) ->addGamma('myGamma', function($obj){ $a++; //OUT OF MY SCOPE

I am trying to understand, how exactly variable binding in python works. Let's look at this: def foo(x): def bar(): print y return bar y = 5 bar = foo(2) bar() This prints 5 which seems reasonable to me. def foo(x): def bar(): print x return bar x = 5 bar = foo(2) bar() This prints 2, which is strange. In the first example python looks for the variable during execution, in the second when the method is created. Why is it so? To be clear: this is very cool and works exactly as I would like it to. However, I am confused about how internal bar function gets its context. I would like to understand

Am getting this issue with this struct, on the line which reads "lazy var townSize: Size ={" and can't figure out what the issue is. struct Town { let region = "South" var population = 5422 var numberOfStoplights = 4 enum Size { case Small case Medium case Large } lazy var townSize: Size = { switch self.population { case 0...10000: return Size.Small case 10001...100000: return Size.Medium default: return Size.Large } } func printTownDescription() { print("Population: \(myTown.population), number of stoplights: \(myTown.numberOfStoplights)") } mutating func changePopulation(amount: Int) {

When I try to compile the following code: fn main() { (...) let mut should_end = false; let mut input = Input::new(ctx); input.add_handler(Box::new(|evt| { match evt { &Event::Quit{..} => { should_end = true; } _ => {} } })); while !should_end { input.handle(); } } pub struct Input { handlers: Vec<Box<FnMut(i32)>>, } impl Input { pub fn new() -> Self { Input {handlers: Vec::new()} } pub fn handle(&mut self) { for a in vec![21,0,3,12,1] { for handler in &mut self.handlers { handler(a); } } } pub fn add_handler(&mut self, handler: Box<FnMut(i32)>) { self.handlers.push(handler); } } I get this