window.event の標準化及び使用の是非について | teratail
Q1.について 標準化されていないと思います。 私も、7.2 The Window object - HTML Standardを見ましたが、 該当するような箇所は見つかりませんでした。 w3cの仕様でもそうですね。 Q2.について 他のイベントが発火したら書き換えられる不安定なもの、という意味では、 イベントハンドラで処理している間に他のスレッドから書き換えられる事は、 仕様上は無いので、問題なさそうです。 ブラウザにバグがあって仕様を満たしていない場合は、 どうしようもありませんが。 Javascriptでのスレッドは、メインのスレッド1つと、Web Workerのスレッドしかなく、 Web Workerからはwindowオブジェクトを参照、操作できないためです。 Javascriptがシングルスレッドという事について 仕様のどの部分によるものか、私も気になっていましたので、 この機会
GitHub - ljharb/String.prototype.matchAll: Spec-compliant polyfill for String.prototype.matchAll ESnext proposal.
const assert = require('assert'); const matchAll = require('string.prototype.matchall'); const str = 'aabc'; const nonRegexStr = 'ab'; const globalRegex = /[ac]/g; const nonGlobalRegex = /[bc]/i; // non-regex arguments are coerced into a global regex assert.deepEqual( [...matchAll(str, nonRegexStr)], [...matchAll(str, new RegExp(nonRegexStr, 'g'))] ); assert.deepEqual([...matchAll(str, globalRegex
ECMAScript 2015 Language SpecificationのIntroductionから4章まで - Qiita
ECMAScript 2015 Language Specification一人輪読会資料。（やりたいチームメンバーがいればいつでもウェルカムなので、もしかしたらそのうち普通の輪読会になるかも） Introduction このECMA標準はECMAScript 2015を定義するものである 1997年に第1版が出て、今回で第6版 ECMAScript2015のゴール 大規模アプリケーション開発、ライブラリ開発、多言語のコンパイルターゲットとしての利用へのより良いサポート ECMAScriptの歴史 Wikipedia見たほうが図があっていいかも 1 Scope この標準はECMAScript2015多目的プログラミング言語を定義している 2 Conformance 適合条件っぽい。 conformance => 適合・準拠 ECMAScriptに適合する実装は、 （ES5と変わらないとこ）
sirisian/ecmascript-types: ECMAScript Optional Static Typing Proposal
With TypedArrays and classes finalized, ECMAScript is in a good place to finally discuss types again. The demand for types as a different approach to code has been so strong in the past few years that separate languages have been created to deal with the perceived shortcomings. Types won't be an easy discussion, nor an easy addition, since they touch a large amount of the language; however, they a
Tasks, microtasks, queues and schedules
Posted 17 August 2015 - hold onto your butts for this one, it's spec-heavy When I told my colleague Matt Gaunt I was thinking of writing a piece on microtask queueing and execution within the browser's event loop, he said "I'll be honest with you Jake, I'm not going to read that". Well, I've written it anyway, so we're all going to sit here and enjoy it, ok? Actually, if video's more your thing, P
25981 – ES6 integration
https://mail.mozilla.org/pipermail/es-discuss/2014-July/038406.html When an event loop is created, invoke the algorithm in 8.5 Initialization. Step 7 should obtain zero scripts. This results in 8.4.2 NextTask being invoked. 8.4.2 NextTask is adjusted as follows: The "implementation defined unhandled exception processing" in step 1 must be the "report an error" logic in the HTML spec. The "implemen
@@toStringTag spoofing for null and undefined
According to 19.1.3.6 Object.prototype.toString() 1, it's possible to do this: function Foo(){} Foo.prototype[Symbol.toStringTag] = "Null"; Object.prototype.toString.call(new Foo()); // "[object Null]" It seems like "Null" and "Undefined" should be added to the step 17(b) list of exceptions to prevent spoofing of null and undefined values using this approach. I couldn't think of a reason why the c
Template site objects and WeakMap
In ES6 spec, template site objects are strongly referenced by the realm.[[templateMap]]. So naive implementation leaks memory because it keeps all the site objects in the realm. However, we can alleviate this situation. Because template site objects are frozen completely, it behaves as if it's a primitive value. It enables the implementation to reference it from the realm weakly. When all disclose
ECMAScript 2015 is now an Ecma Standard
Ecma international has announced that its General Assembly has approved ECMA-262-6 The ECMAScript 2015 Language Specification as an Ecma standard www.ecma-international.org/news/index.html The official document is now available from Ecma in HTML at www.ecma-international.org/ecma-262/6.0 and as a PDF at www.ecma-international.org/ecma-262/6.0/ECMA-262.pdf I recommend that people immediately start
Extensible Operators and Literals for JavaScript
Extensible Operators and Literals for JavaScriptAI-enhanced description The document discusses various value types and their implementations in JavaScript, focusing on new literal syntax and overloadable operators. It explains operator overloading, strict equality operators, and the proposed cacheable multimethods as a solution to double dispatch issues. Additionally, it provides examples of opera
GitHub - leebyron/spec-md: 📖 Additions to Markdown for writing specification documents
Renders Markdown with some additions into an HTML format commonly used for writing technical specification documents. Markdown additions include code syntax highlighting, edit annotations, and the definition of algorithms and grammar productions. Philosophy Spec Markdown is first and foremost Markdown. As such, it follows Markdown's philosophy of intending to be as easy to read and easy to write a
リリース、障害情報などのサービスのお知らせ
最新の人気エントリーの配信
j次のブックマーク
k前のブックマーク
lあとで読む
eコメント一覧を開く
oページを開く
GitHub - tc39/proposal-class-public-fields: Stage 2 proposal for public class fields in ECMAScript
GitHub - lars-t-hansen/ecmascript_sharedmem: Placeholder for old shared memory spec
GitHub - tc39/proposal-string-left-right-trim: A proposal to the ECMAScript standard for including left and right trim of whitespace to strings
Bug 4432 – String.prototype.split should revert to ES5 behavior, using ToUint32 to coerce limit argument
GitHub - domenic/unhandled-rejections-browser-spec: Spec patches for HTML and ES for tracking unhandled promise rejections with events
Define a process for feature proposals (RFCs) · Issue #16 · tessel/project
GitHub - tc39/proposal-regex-escaping: Proposal for investigating RegExp escaping for the ECMAScript standard
GitHub - tc39/ecma402: Status, process, and documents for ECMA 402
GitHub - tc39/Function-prototype-toString-revision: :fishing_pole_and_fish: ECMA-262 proposal to update Function.prototype.toString
