ES2020: `import()` – dynamically importing ES modules
Warning: This blog post is outdated. Instead, read section “Loading modules dynamically via import()” in “Exploring JavaScript”. The ECMAScript proposal “import()” by Domenic Denicola is at stage 4 and part of ECMAScript 2020. It enables dynamic loading of ECMAScript modules and is explained in this blog post. ECMAScript modules are static # ECMAScript modules are completely static: you must spec
GitHub - tc39/proposal-async-iteration: Asynchronous iteration for JavaScript
The iterator interface (introduced in ECMAScript 2015) is a sequential data access protocol which enables the development of generic and composable data consumers and transformers. Their primary interface is a next() method which returns a { value, done } tuple, where done is a boolean indicating whether the end of the iterator has been reached, and value is the yielded value in the sequence. Sinc
アロー関数が実装された - JS.next
概要 ES2015を象徴する機能である、アロー関数構文の実装がついにV8で始まった。 無名関数を短く書ける [3.28.31] アロー関数は無名関数の省略記法である。 今までこう書いていたのが、 var fn = function (a, b) { } こうスッキリ書ける。 var fn = (a, b) => { } 「=>」が矢のように見えることから「アロー」関数と言う。 更に短くできる これが、 [1, 2, 3].map( function (v) { return v * v } ) // [1, 4, 9] アロー関数だとこうなるが、 [1, 2, 3].map( (v) => { return v * v } ) // [1, 4, 9] 引数が一つの時には「()」を省略できるので、こう書ける。 [1, 2, 3].map( v => { return v * v } )
Creating defensive objects with ES6 proxies - Human Who Codes
Posted at April 22, 2014 by Nicholas C. Zakas Tags: ECMAScript 6, JavaScript, Proxies This past week I spent an hour debugging an issue that I ultimately tracked down to a silly problem: the property I was referencing didn’t exist on the given object. I had typed request.code and it should have been request.query.code. After sternly lecturing myself for not noticing earlier, a pit formed in my sto
Understanding ECMAScript 6
ECMAScript 6 represents the biggest change to the core of JavaScript in the history of the language. Not only does the sixth edition add new object types, but also new syntax and exciting new capabilities. The result of years of study and debate, ECMAScript 6 reached feature complete status in 2014. While it will take a bit of time before all JavaScript environments support ECMAScript 6, it's stil
Promiseについて - JS.next
概要 Promiseとは非同期処理を上手く扱う為のAPIであり、パターンである。 非同期の処理の完了後に続けて処理を行いたいとき、よくコールバックパターンが使われるが、処理が連続するとコールバック地獄と言われる分かりづらいソースコードになってしまう。 また、複数の非同期処理が完了した時に処理を行うなど、コールバックパターンでは難しい事をスマートにできるのがこのPromiseである。 今まではDOMの方でDOM Promiseとして仕様策定が進められていたり、ライブラリのDeferredが有名だったが、ES2015標準に入ることになり、V8に実装された。 実装されたメソッド Promise.resolve(x) Promise.reject(x) Promise.all( [p1, p2, p3, ......] ) Promise.race( [p1, p2, p3, ......] )
Annotated ES5 - 15.11.1 The Error Constructor Called as a Function
This is not the normative ECMAScript Language specification. The normative spec (ECMA 262) is a PDF file maintained by ECMA TC39 and is available from http://www.ecmascript.org/. An auto-generated HTML version is available, too: http://ecma-international.org/ecma-262/5.1/ This is an annotated, hyperlinked, HTML version of Edition 5.1 of the ECMAScript Specification, the source for which is maintai
ECMAScript.Next ECMAScipt 6
This document discusses the history and evolution of JavaScript and ECMAScript. It begins with the origins of JavaScript in the mid-1990s as LiveScript and Mocha, developed by Netscape. JavaScript was standardized by Ecma International as ECMAScript, with various versions released over time adding new features. The presentation focuses on the latest ECMAScript 6 specification, covering new feature
ECMAScript 6 and Rest Parameter · ariya.io
ECMAScript 6 and Rest Parameter Mar 6, 2013 2 min read #es6 #javascript #web Handling a function with a variable number of arguments is always tricky in JavaScript. At least, we still have this arguments object which can be used to retrieve all arguments used to invoke a function. With the upcoming ECMAScript 6, no such hack is necessary anymore since we can start using its rest parameter feature.
ECMAScript 6 and Object Literal Property Value Shorthand · ariya.io
ECMAScript 6 and Object Literal Property Value Shorthand Feb 28, 2013 2 min read #es6 #javascript #web Constructing an object using the literal syntax is something that is very familiar to every JavaScript developer, quite likely because this reminds everyone of JSON. While every object property needs to be either a key-value pair or getter/setter, this may change in the near future. Another synta
A first look at what might be in ECMAScript 7 and 8
Brendan Eich mentions features that are candidates for ECMAScript 6, 7 and 8: ECMAScript 6: modules and shallow continuations. These things have been known for a while – see [1]. ECMAScript 7: guards, contracts, event loop concurrency. ECMAScript 8: macros, parallel arrays (SIMD) [background]. It is interesting that the goal of some features is to make JavaScript a better compilation target [2]. I
ECMAScript.next: TC39’s July 2012 meeting
TC39 (Technical Committee 39) works on the upcoming ECMAScript.next [1] standard. They have several meetings per year and in July, there was another one. This blog post summarizes the most important decisions. It is based on the following minutes by Rick Waldron: July 24, 2012 July 25, 2012 July 26, 2012 Introduction In this post, I have omitted all decisions that concern minor details or that it
ECMAScript 6: classes
[Update 2015-02-15] Newer version of this blog post: “Classes in ECMAScript 6 (final semantics)” During the July 2012 meeting of TC39 [1], classes have been accepted for ECMAScript 6, the upcoming version of the JavaScript language standard. This blog post explains how those classes work. It is based on Allen Wirfs-Brock’s annotated slides. Overview An ECMAScript 6 class is syntactic sugar for a c
What is the meaning of this?
YUI Blog Development What is the meaning of this? What is the meaning of this? JavaScript is an amalgam of good parts and bad parts. Its best parts came from Self (prototypes) and Scheme (lexically scoped nested functions). But the interaction of those two very good parts produced some bad parts. When a function is called with the function invocation pattern, its this is not bound to the outer fun
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GitHub - zenparsing/esdown: ES6+ to ES5 Compiler
GitHub - tc39/proposal-pipeline-operator: A proposal for adding a useful pipe operator to JavaScript.
Working with grapheme clusters
ECMAScript 6: what’s next for JavaScript? (June 2014)
JavaScript (ECMAScript) 2013
Code Tutorials | Envato Tuts+
