closures

问题 Crockford introduces a pattern in the deentityify method to create a module. He claims: The module pattern takes advantage of function scope and close to create relationships that are binding and private. In this example, only the deentityify method has access to the entity data structure. Distilling to remove his custom functions, I think the code boils down to... String.prototype.deentityify = function() { var entity = { quot: '"', lt: '<', gt: '>' }; return function() { return this.replace

问题 This seems impossible (and it might be), but I'm trying to get into more TDD and I keep hitting a wall with closures. Say I have the following: function createSomething(init) { function privateMethod(param) { return init[param]; //assuming this is more complicated, how can you test it? } function getData() { return init.data; } function getValue(name) { if (name === "privateNode" || typeof name !== "string") { return "permissionDenied"; } return privateMethod(name); } return { getData :

问题 I'm currently working on a LISP interpreter written in Java. Now I stuck at the closures. I want to enable closures like this: (define a 1000) (define closure (lambda (a) (lambda (b) (+ a b)))) (define x (closure 10)) (x 20) --> 30 So, (x 20) should return 30 . But, guess what, it returns 1020 in my interpreter. I think the mistake is in my lambda class. It looks like this: public class LLambda extends LOperation { private LList parameters; private LList definitions; public LLambda(LList

问题 Recently i faced one problem in hackerrank which has to calculate multiplication operation and has to return the answer. For example function multiply(a,b) { return a*b; } Now here is the problem the function might call in different ways such as multiply(4,5); multiply(4)(5); multiply(4)(5)(6); I know we have to closure apporach for the second one which is multiply(4)(5). I had written code for that function multiply(a,b) { return function(b) { return a*b; } } Now what if its been multiply

问题 When rethinking my everyday programming patterns to be more swifty , there is one, that I really struggle with: observing changes . After a lot of thinking and research I have yet to find a satisfying solution . That is one, that is easy to use, leverages the full potential of swift's strong type system, is compatible with value types and allows for static dispatch. Maybe the latter one is not possible and that's the reason why my search is unsuccessful so far. If so, I would like to know why

问题 This question is based on the answer given by one of my favourite posters Mehrdad Afshari in this question about closure. I am having a hard time understand why C# generates the code the way it does...... Here is the code in question static void Main(string[] args) { List<string> list = new List<string> { "hello world", "TED", "goodbye world" }; IEnumerable<string> filteredList1 = list; IEnumerable<string> filteredList2 = list; var keywords = new[] { "hello", "world" }; foreach (var keyword

问题 In the following use case, I'm trying to animate the lineWidth of an SKShapeNode . SKEase is part of the wonderful SpriteKitEasing github repo from Craig Grummitt. One of its facilities is a Float changing ease action that appears to change the value of a float over time. However I can't figure out how to use it. Xcode gives the following suggestions when typing it in: let lineWeight = SKEase.createFloatTween(<start: CGFloat, end: CGFloat, time: TimeInterval, easingFunction: AHEasingFunction,

问题 Given the following simplified program: #[macro_use] extern crate log; extern crate ansi_term; extern crate fern; extern crate time; extern crate threadpool; extern crate id3; mod logging; use std::process::{exit, }; use ansi_term::Colour::{Yellow, Green}; use threadpool::ThreadPool; use std::sync::mpsc::channel; use std::path::{Path}; use id3::Tag; fn main() { logging::setup_logging(); let n_jobs = 2; let files = vec!( "/tmp/The Dynamics - Version Excursions/01-13- Move on Up.mp3", "/tmp/The

问题 I am newbie in JavaScript, I have an idea, to create class (function), I know how it works in JS (prototypes and so on), but I need to do something like incrementing Id in databases. My idea is to create static method, I think closure will suit great here and whenever new object is created it should return incremented id. I don't know what is the right way to implement this, or maybe this is bad practice. Please provide simple example. 回答1: Closure is a good idea: var MyClass = (function() {

问题 I am trying to reproduce some code from the book "Javascript: The Good Parts" by Douglas Crockford. The idea is to use closures for object encapsulation and avoid Javascript's inherent global variables. var serial_maker = function ( ) { // Produce an object that produces unique strings. A // unique string is made up of two parts: a prefix // and a sequence number. The object comes with // methods for setting the prefix and sequence // number, and a gensym method that produces unique //