arv

At the July TC39 meeting we decided to explore removing @@create in favor of a model where super() in a [[Construct]] call creates the instance object. To correctly know how to create the instance and set the prototype a [[Construct]] call gets an implicit receiver which is the constructor function new was called with.

class Base {
  constructor() {
    var object = Object.create(new*.prototype);  // new binding needs new syntax...
                                                 // bikeshed...
    myWeakMap.set(object, myHiddenData);
    return object;
 }

arv

// Use Gists to store code you would like to remember later on
console.log(window); // log the "window" object to the console

arv

13.10.4 Runtime Semantics: Evaluation

WithStatement : with ( Expression ) Statement

1. Let val be the result of evaluating Expression.
2. Let obj be ToObject(GetValue(val)).
3. ReturnIfAbrupt(obj).
4. Let oldEnv be the running execution context’s LexicalEnvironment.
5. Let newEnv be NewObjectEnvironment(obj, oldEnv).

arv

class B {
  constructor(x) {
    this.x = x;
  }
  static [Symbol.create]() {
    var o = super();
    weakMap.set(o, 123456789);  // Dom wrapper foo
    return o;
 }

arv

<link rel="import" href="../core-scaffold/core-scaffold.html">
<link rel="import" href="../core-header-panel/core-header-panel.html">
<link rel="import" href="../core-menu/core-menu.html">
<link rel="import" href="../core-item/core-item.html">
<link rel="import" href="../core-icon-button/core-icon-button.html">
<link rel="import" href="../core-toolbar/core-toolbar.html">
<link rel="import" href="../core-menu/core-submenu.html">
<link rel="import" href="../google-map/google-map.html">

<polymer-element name="my-element">

arv

if (!Document.prototype.createAttributeNS) {
  Document.prototype.createAttributeNS = function(namespaceURI, qualifiedName) {
    var dummy = this.createElement('dummy');
    dummy.setAttributeNS(namespaceURI, qualifiedName, '');
    var attr = dummy.attributes[0];
    dummy.removeAttributeNode(attr);
    return attr;
  };
}

arv

(function() {
  'use strict';

  function uncurryThis(f) {
    return f.call.bind(f);
  }

  var ShadowRoot = window.ShadowRoot;
  var createShadowRoot = uncurryThis(Element.prototype.createShadowRoot);
  var ownerDocumentGetter = uncurryThis(Object.getOwnPropertyDescriptor(Node.prototype, 'ownerDocument').get);