closures

I found the following piece of JavaScript code (maybe here at Stack Overflow?) for implementing a timeout: var delay = (function() { var timer = 0; return function(callback, ms) { clearTimeout(timer); timer = setTimeout(callback, ms); }; })(); I'm new to JavaScript, so I'm still trying to wrap my head around closures. If I call delay(firstCallback, 200) in one place and then delay(secondCallback, 200) right after, the first timeout callback is cleared, while the second callback executes successfully. How do I reuse delay in different instances without overwriting other instances? (Not sure if

I'm trying to remove an event listener for created span elements where the function called is within a closure. I've tried various methods and none seem to work. var MyClass = function () {} MyClass.prototype.addSpan = function (el) { var span = document.createElement('span'); span.innerHTML = "Text here"; el.appendChild(span); span.addEventListener('click', (function (obj) { return function () { obj.removeSpan(); } })(this), false); } MyClass.prototype.removeSpan = function () { alert('removing span'); this.removeEventListener('click', arguments.callee, false); // .... remove span .... }

I'm trying to break up code that makes use of the Jenkins Job DSL plugin into reusable pieces, and I suspect that my question is generic to Groovy and not Jenkins-specific. For example, I want to reuse parts of this block: freeStyleJob() { //generic stuff name "something" description "something else" //custom stuff scm { svn { //etc.... } } } By placing name and description in a utility method (obviously I want to do more than just that in real life). However, I cannot find the proper syntax to create a closure for the current scope. Here is how I think it should look: def jobCommonItems() {

I'm trying to store a closure as a HashMap value. If I pass the closure arg by value, everything works great: use std::collections::hash_map::HashMap; fn main() { let mut cmds: HashMap<String, Box<FnMut(String)->()>> = HashMap::new(); cmds.insert("ping".to_string(), Box::new(|&mut:s| { println!("{}", s); })); match cmds.get_mut("ping") { Some(f) => f("pong".to_string()), _ => () } } ( playpen ) But if I want a closure that takes a reference arg, things go south: use std::collections::hash_map::HashMap; fn main() { let mut cmds: HashMap<String, Box<FnMut(&str)->()>> = HashMap::new(); cmds

Problem & Reason One of my team mate ended up in messy situtaion implementing function hooking in javascript. this is the actual code function ActualMethod(){ this.doSomething = function() { this.testMethod(); }; this.testMethod = function(){ alert("testMethod"); }; } function ClosureTest(){ var objActual= new ActualMethod(); var closeHandler = objActual.doSomething; closeHandler(); closeHandler.apply(objActual,arguments); //the fix i have added this.ActualTest = function() { alert("ActualTest"); }; } In the above code, var closeHandler is created in the context of ClosureTest(), but it holds

Precedence rules for same name and signature function & closure When defining a closure and a function with same name (say, foo ) and signature, it seems as if the closure takes precedence when calling said (seemingly ambiguous) foo . // Int -> () function func foo(num: Int) { print("function \(num)")} // Int -> () closure let foo: (Int) -> () = { print("closure \($0)")} /* or... let foo = { (num: Int) in print("closure \(num)")} */ foo(1) // closure 1 If I option-click the two declarations, they point at each other under the label Related declarations , differing in how they are referred to

This question is largely based on this one: Link The main difference being that I want to pass in arguments to the closure as well. Say I have something like this: func someFunctionThatTakesAClosure(completionClosure: (venues: Dictionary<String, AnyObject>, error: NSError) -> ()) { // function body goes here var error: NSError? let responseDictionary: Dictionary<String, AnyObject> = ["test" : "test2"] completionClosure(venues: responseDictionary, error: error!) } No error here. But when I call this function in my main view controller I have tried several ways but all of the result in different