closures

问题 I am trying to understand how parameters passed to a method are available to nested closures. I'm nervous that something I wrote won't always have the original parameters available. (these are drastically simplified examples) I have a method that I wrote that specifies a closure as a parameter: func saveNameAndAgeToServer(serverParams: [String:String], completionHandler: (age: NSNumber) -> ()) { // Connect to a server // POST a name and dob from serverParams // Receives a current age in

问题 trying to use a throttling function created by Remy Sharp (http://remysharp.com/2010/07/21/throttling-function-calls/)... it works in the standard use like so: $('.thing').click(throttle(function() { console.log('api call'); }, 300); Which is pretty neat, but I wanted to be able to throttle a specific part of code within a function, not on the entire click event, like so: $('.thing').click(function() { console.log('hello!'); throttle(function() { console.log('api call'); }, 300); }); But I

问题 I've got some rather complicated logic: var myArray = []; var tempInterval = 0; // Run for 6 minutes for(i=0;i<360;i++) { // Closure so that 'i' is the right value when setInterval runs tempInterval = (function(i) { interval1 = setInterval(function() { console.log(i); }, (i * 1000)); return interval1; })(i); // Put the setInterval value into an array myArray.push(tempInterval); } I use a Closure because I need the value of i to be 0,1,2,...etc , and if you don't use a closure, it'll be 360 by

问题 I am constructing an approximating function recursively (adaboost). I would like to create the resulting learning function along the way (not to apply the approximation directly to my test data but keep the function that leads to it) unfortunately, it seems that R updates the value to which a variable name refers to long after it is used. #defined in plyr as well id <- function(x) {x} #my first classifier modelprevious <- function(inputx, k) { k(0)} #one step of my superb model modelf <-

问题 I am building am application with a Firestore back end, and I am trying to call a document down with the current user's info for their settings page. I am able to do this no problems when updating an empty array, but am having a terrible time trying to populate a single document. I have a custom object called DxUser : struct DxUser { var email:String? var name:String? var timeStamp:Date? var profileImageURL:String? var ehr: String? var dictionary:[String:Any]? { return [ "email":email, "name"

问题 While watching Learning to Love JavaScript, I got hung up on why this 2nd version wouldn't work. It just returns 'function'. Is a closure not allowed to have a variable directly assigned to it? function getCtr() { var i = 0; return function() { console.log(++i); } } var ctr = getCtr(); ctr(); ctr(); ctr(); /* console 1 2 3 */ /*-------------------------------------- * This doesn't work */ var ctr = function() { var i = 0; return function() { console.log(++i); } } ctr(); ctr(); ctr(); /*

问题 Basically this is a simple project that involves a tableview that is updated according to data that is parsed from JSON from an api. I believe DispatchQueue.main.async and completed: @escaping () -> () have something to do with updating/reloading the tableview but I'm not sure how it works. Explanation would be appreciated on what these two do. import UIKit class ViewController: UIViewController { @IBOutlet weak var tableView: UITableView! var heroes = [HeroStats]() override func viewDidLoad(

问题 I'm encountering an issue where I have two methods, the first calling the second in a loop and the second creating a Future as follows: public class WorkersCoordinator { private static Logger LOGGER = LoggerFactory.getLogger(WorkersCoordinator.class); private final Timeout timeout; private final ActorSystem system; private final List<Class<? extends BaseWorker>> workers; private final Map<Class, ActorRef> refMap; private final WorkResultPackageQueue pkgQueue; private final ActorFactory

问题 I'm building a list of buttons and I want each one to trigger the addForm() function with the current members[member].id . But it happens that only the last button will fire the event. I know it has something to do with closures and as you can see I have adapted the function to use this pattern. What am I doing wrong? function displayConnections(connections) { /*(...)*/ for (var member in members) { connectionsDiv.innerHTML += "<p>" + members[member].firstName + " " + members[member].lastName

问题 Here's a toy example distilled from a complex class: public class MyClass { public function MyClass() { trace('Created'); } public static function makeObjectAsync(callback:Function):void { inner(); function inner():void { var object:MyClass = new MyClass(); // line 10 callback(object); } } } After calling the static function: MyClass.makeObjectAsync(function(object:Myclass):void { ... }) the following run-time exception occurs at line 10: TypeError: Error #1007: Instantiation attempted on a