Initial pass creating the ES6 feature doc

docs/es6-chromium.md

+<!-- This is feature markdown template
+## Header
+
+**Usage Example:**
+
+``` js
+
+```
+
+**Documentation:** [link]()
+
+**Discussion Notes / Link to Thread:**
+
+hyphen-hyphen-hyphen (change to actual hyphen)
+
+-->
+
+
+<style type="text/css">
+  .doc {
+    font-size: 16px;
+  }
+
+  .doc h2[id] {
+    line-height: 20px;
+    font-size: 16px;
+  }
+
+  .doc h2 > code {
+    font-size: 16px;
+    font-weight: bold;
+  }
+
+  .feature-container {
+    background-color: #e8eef7;
+    border: 1px solid #c3d9ff;
+    margin-bottom: 5px;
+    border-radius: 5px;
+  }
+
+  .feature-container > h2 {
+    cursor: pointer;
+    background-color: #c3d9ff;
+    margin: 0;
+    padding: 5px;
+    border-radius: 5px;
+  }
+
+  .feature-container > *:not(h2){
+    display: none;
+    padding: 0px 10px;
+  }
+
+  .feature-container.open > *:not(h2){
+    display: block;
+  }
+</style>
+
+<script>
+document.addEventListener("DOMContentLoaded", function(event) {

[Dan Beam, 2016/11/30 23:08:54]

prefer single quotes always

[Dan Beam, 2016/12/07 19:41:40]

Done.

+  // Move all headers and corresponding contents to an accordion container.
+  document.querySelectorAll('h2[id]').forEach(function(header){

[Dan Beam, 2016/11/30 23:08:53]

document.querySelectorAll('h2[id]').forEach(function(header){
                                             space here == ^^

[Dan Beam, 2016/12/07 19:41:39]

Done.

+    var container = document.createElement('div');
+    container.classList.add('feature-container');
+    header.parentNode.insertBefore(container, header);
+
+    // Add all the following siblings until it hits an <hr>
+    var ele = header;

[Dan Beam, 2016/11/30 23:08:53]

ele -> el everywhere

[Dan Beam, 2016/12/07 19:41:39]

Done.

+    while(ele && ele.tagName !== 'HR') {

[Dan Beam, 2016/11/30 23:08:53]

while(ele
    ^^
space here

[Dan Beam, 2016/12/07 19:41:39]

Done.

+      var nextEle = ele.nextElementSibling;
+      container.append(ele);
+      ele = nextEle;
+    }
+
+    // Add handler to open accordion on click.
+    header.addEventListener('click', () => {

[Dan Beam, 2016/11/30 23:08:53]

you should arguably wait until we support => before doing this ;)

[Dan Beam, 2016/12/07 19:41:40]

Done.

+      header.parentNode.classList.toggle('open');
+    });
+  });
+
+  // Then remove all <hr>s since everything's accordionized.
+  document.querySelectorAll('hr').forEach(function(ele){
+    ele.parentNode.removeChild(ele);
+  });
+});
+</script>
+
+[TOC]
+
+# ES6 Support In Chromium
+
+This is a list of new/updated features in ES6 specs that is being considered to
+be supported for Chromium development.
+
+>**TBD:** Do we want to differenciate allow/ban status between subprojects? If
+so, how to denote?
+
+>**TBD:** Cross platform-build support?
+
+You can propose changing the status of a feature by sending an email to
+chromium-dev@chromium.org. Include a short blurb on what the feature is and why
+you think it should or should not be allowed, along with links to any relevant
+previous discussion. If the list arrives at some consensus, send a codereview
+to change this file accordingly, linking to your discussion thread.
+
+>Some descriptions and Usage examples are from [kangax](https://kangax.github.
+io/compat-table/es6/) and [http://es6-features.org/](http://es6-features.org/)
+
+# Allowed Features
+
+The following features are allowed in Chromium development.
+
+## `Promise`
+
+Built-in representation of a value that might be determined asynchronously,
+relieving developers from "callback hell".

[Dan Beam, 2016/11/30 23:08:53]

can we steal more from
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Obje...
?

The Promise object is used for asynchronous computations. A Promise represents a
value which may be available now, or in the future, or never.

[Dan Beam, 2016/12/07 19:41:40]

Done.

+
+**Usage Example:**
+
+``` js
+function promiseA() {
+  return new Promise((resolve, reject) => setTimeout(resolve, 100));
+}
+
+function promiseB() {
+  return new Promise((resolve, reject) => setTimeout(resolve, 200));
+}
+
+function promiseC() {
+  return new Promise((resolve, reject) => setTimeout(resolve, 300));
+}
+
+Promise.all([promiseA(), promiseB(), promiseC()]).then(([a, b, c]) => {
+  someFunction(a, b, c);
+});

[Dan Beam, 2016/11/30 23:08:54]

can you use less ES6 features in this example?

how about:

/** @type {!Promise} */
var fullyLoaded = new Promise(function(resolve) {
  function isLoaded() { return document.readyState == 'complete'; }

  if (isLoaded()) {
    resolve();
  } else {
    document.onreadystatechange = function() {
      if (isLoaded()) resolve();
    };
  }
});

...

loaded.then(startTheApp);

[Dan Beam, 2016/12/07 19:41:39]

Done.

+```
+
+**Documentation:** [link](http://www.ecma-international.org/ecma-262/6.0
+/#sec-promise-objects)
+
+**Discussion Notes:** Feature already extensively used prior to creation of
+this document.
+
+---
+
+# Banned Features
+
+The following features are banned for Chromium development.
+
+# Features To Be Discussed
+
+The following features are currently disallowed. See the top of this page on
+how to propose moving a feature from this list into the allowed or banned
+sections.
+
+## `let` (Block-Scoped Variables)
+
+Declare variable that exists within the block scope. `let` can generally be

[Dan Beam, 2016/11/30 23:08:52]

`let` declares a variable within the scope of a block.  This differs from `var`,
which uses function level scope.

then we should borrow the example from MDN:

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/...

function varTest() {
  var x = 1;
  if (true) {
    var x = 2;  // same variable!
    console.log(x);  // 2
  }
  console.log(x);  // 2
}

function letTest() {
  let x = 1;
  if (true) {
    let x = 2;  // different variable
    console.log(x);  // 2
  }
  console.log(x);  // 1
}

[Dan Beam, 2016/12/07 19:41:39]

Done.

+used to replace `var` but `let` in global scope, unlike `var`, does not
+introduce a property on the global object.
+
+**Usage Example:**
+
+``` js
+// This will make all buttons output "3".
+for(var i = 0; i < 3; i++) {
+  buttons[i].onclick = function() {
+    console.log(i);
+  };
+}
+
+// This will make buttons output corresponding "i" values.
+for(let i = 0; i < 3; i++) {
+  buttons[i].onclick = function() {
+    console.log(i);
+  };
+}
+
+var bar = 1;
+var bar = 1; // No error thrown.
+
+let foo = 1;
+let foo = 1; // TypeError: Identifier 'foo' has already been declared.
+```
+
+**Documentation:** [link](http://www.ecma-international.org/ecma-262/6.0
+/#sec-let-and-const-declarations)
+
+**Discussion Notes / Link to Thread:**
+
+---
+
+## `const` (Block-Scoped Constants)
+
+Constants (also known as "immutable variables") are variables which cannot be
+re-assigned new content. Note that if the value is an object, the object itself
+is still mutable.
+
+`const` has traditionally been supported as a "function scoped" declaration
+like `var` (except in Internet Explorer), however in VMs supporting ES6 `const`
+is now a block scope declaration.

[Dan Beam, 2016/11/30 23:08:53]

i would drop this an just say "Also note that in Chrome, `const` is block scoped
like `let`" as it doesn't matter what IE does in our case

[Dan Beam, 2016/12/07 19:41:39]

Done.

+
+**Usage Example:**
+
+``` js
+const gravity = 9.81;
+gravity = 0; // TypeError: Assignment to constant variable.
+
+gravity === 9.81; // true

[Dan Beam, 2016/11/30 23:08:53]

can we put an example of an object?

const frobber = {isFrobbing: true};
frobber = {isFrobbing: false};  // TypeError: Assignment to constant variable.
frobber.isFrobbing = false;  // works

See also:
[Object.freeze()](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/freeze).

[Dan Beam, 2016/12/07 19:41:39]

Done.

+```
+
+**Documentation:** [link](http://www.ecma-international.org/ecma-262/6.0
+/#sec-let-and-const-declarations)
+
+**Discussion Notes / Link to Thread:**
+
+---
+
+## `=>` (Arrow Functions)
+
+Arrow functions provide a concise syntax to create a function, and fix a number
+of difficulties with this (e.g. eliminating the need to write `const self =
+this`. Particularly useful for nested functions or callbacks.
+
+Prefer arrow functions over the function keyword, over `f.bind(this)`, and
+especially over `goog.bind(f, this)`.

[Dan Beam, 2016/11/30 23:08:53]

we don't use closure, so goog.bind() isn't really as popular in our codebase...

[Dan Beam, 2016/12/07 19:41:39]

Done.

+
+Arrow functions has an implicit return when used without a body block.
+
+**Usage Example:**
+
+``` js
+// General usage, eliminating need for .bind(this).
+setTimeout(() => {
+  this.doSomething();
+}, 1000);  // no need for .bind(this) or const self = this.
+
+// Another example...
+window.addEventListener('scroll', (event) => {
+  this.doSomething(event);
+});  // no need for .bind(this) or const self = this.
+
+// Implicit return: returns the value if expression not inside a body block.
+() => 1 // returns 1
+() => {1} // returns undefined - body block does not implicitly return.
+() => {return 1;} // returns 1

[Dan Beam, 2016/11/30 23:08:52]

nit: two spaces before the comment starts (right now you have 1)

[Dan Beam, 2016/12/07 19:41:39]

Done.

+```
+
+**Documentation:** [link](http://www.ecma-international.org/ecma-262/6.0
+/#sec-arrow-function-definitions)
+
+**Discussion Notes / Link to Thread:**
+
+---
+
+## Classes
+
+OOP-style and boilerplate-free class syntax, including inheritance, super(),
+static members, and getters and setters.
+
+**Usage Example:**
+
+``` js

[Dan Beam, 2016/11/30 23:08:52]

class Shape {
  constructor(id, x, y) {
    this.x = x;
    this.y = y;
  }
}

[Dan Beam, 2016/12/07 19:41:39]

Done.

+class Rectangle extends Shape {

[dpapad, 2016/11/23 01:39:38]

Can you also include the definition of the Shape class? It will make the example
more complete. Also, it seems that the move() method belongs in the superclass,
since it only accesses properties of the superclass.

[Dan Beam, 2016/12/07 19:41:39]

Done.

+  constructor(id, x, y, width, height) {
+    super(id, x, y);
+    this.width  = width;
+    this.height = height;
+  }
+  static defaultRectangle() {

[Dan Beam, 2016/11/30 23:08:53]

more nerd points for

static goldenRectangle() {
  var PHI = (1 + Math.sqrt(5)) / 2;
  return new Rectangle('golden', 0, 0, PHI, 1);
}

[Dan Beam, 2016/12/07 19:41:39]

Done.

+    return new Rectangle('default', 0, 0, 100, 100);
+  }
+  move(x, y) {
+    this.x = x;
+    this.y = y;
+  }
+};

[Dan Beam, 2016/11/30 23:08:53]

can you drop the ; from this?  it's only kinda desired when the result of an
expression, i.e.

let Shape = class {
  ...
};

[Dan Beam, 2016/12/07 19:41:39]

Done.

+```
+
+**Documentation:** [link](http://www.ecma-international.org/ecma-262/6.0
+/#sec-class-definitions)
+
+**Discussion Notes / Link to Thread:**
+
+---
+
+## Block Scope Functions
+
+**Usage Example:**
+
+``` js
+{
+  function foo() {
+    return 1;
+  }
+  // foo() === 1
+  {
+    function foo() {
+      return 2;
+    }
+    // foo() === 2
+  }
+  // foo() === 1
+}
+```
+
+**Documentation:** [link](http://www.ecma-international.org/ecma-262/6.0
+/#sec-functiondeclarationinstantiation)
+
+**Discussion Notes / Link to Thread:**
+
+---
+
+## Default Function Parameters
+
+**Usage Example:**
+
+``` js
+function f(x, y = 7, z = 42) {

[Dan Beam, 2016/11/30 23:08:54]

nit: I think this is a more useful example

/**
 * @param {!Element} element An element to hide.
 * @param {boolean=} animate Whether to animatedly hide |element|.
 */
function hide(element, animate = true) {
  function setHidden() { element.hidden = true; }

  if (animate)
    element.animate({...}).then(setHidden);
  else
    setHidden();
}

[Dan Beam, 2016/12/07 19:41:40]

Done.

+  return x + y + z;
+}
+// f(1) === 50;
+```
+
+**Documentation:** [link](http://www.ecma-international.org/ecma-262/6.0
+/#sec-functiondeclarationinstantiation)
+
+**Discussion Notes / Link to Thread:**
+
+---
+
+## Rest Parameters
+
+Aggregation of function arguments into one Array variable.
+
+**Usage Example:**
+
+``` js
+function f(x, y, ...a) {
+  // for f(1, 2, 3, 4, 5)...

[dpapad, 2016/11/23 01:39:38]

These comments threw me off. It looks like a commented out "for" loop that is
missing open/closing brackets. The '...' and the indentation are the culprits I
think. How about the following?

function f(x, y, ...a) { console.log(x, y, a); }
f(1, 2, 3, 4, 5) // prints "1 2 [3, 4, 5]"

[Dan Beam, 2016/11/30 23:08:54]

i agree but I think this would be even simpler:

function usesRestParams(a, b, ...theRest) {
  console.log(a);  // 'a'
  console.log(b);  // 'b'
  console.log(theRest);  // [1, 2, 3]
}

usesRestParams('a', 'b', 1, 2, 3);

+    // x = 1, y = 2
+    // a = [3, 4, 5]
+}
+```
+
+**Documentation:** [link](http://www.ecma-international.org/ecma-262/6.0
+/#sec-function-definitions)
+
+**Discussion Notes / Link to Thread:**
+
+---
+
+## Spread Operators
+
+Spreading the elements from an iterable collection into individual literals as
+function parameters.
+
+**Usage Example:**
+
+``` js
+// Spreading an Array
+var params = [ 'hello', true, 7 ];
+var other = [ 1, 2, ...params ]; // [ 1, 2, 'hello', true, 7 ]
+f(1, 2, ...params) === 9;

[dpapad, 2016/11/23 01:39:38]

After reading this line, I am still not sure how does |params| gets represented
inside the function Perhaps it would help if you define that function here and
add console.logs() inside it to illustrate. Also comparing the result to "9"
seems arbitrary, and could not tell how it benefits the example.

[Dan Beam, 2016/11/30 23:08:53]

agreed, can we drop this line until we find a less cryptic example?

[Dan Beam, 2016/12/07 19:41:39]

Done.

+
+// Spreading a String
+var str = 'foo';
+var chars = [ ...str ]; // [ 'f', 'o', 'o' ]
+```
+
+**Documentation:** [link](http://www.ecma-international.org/ecma-262/6.0
+/#sec-argument-lists-runtime-semantics-argumentlistevaluation)
+
+**Discussion Notes / Link to Thread:**
+
+---
+
+## Object Literal Extensions
+
+Convenient new ways for object property definition.
+
+**Usage Example:**
+
+``` js
+// Computed property name
+var x = 'key';
+var obj = {[x]: 1};

[Dan Beam, 2016/11/30 23:08:53]

var prop = 'foo';
var o = {
  [prop]: 'hey',
  ['b' + 'ar']: 'there',
};
console.log(o);  // {foo: 'hey', bar: 'there'}

from
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/O...

[Dan Beam, 2016/12/07 19:41:39]

Done.

+
+// Shorthand property
+var obj = {x, y}; //equivalent to {x:x, y:y}

[dpapad, 2016/11/23 01:39:38]

Where is y defined? I understand that this is not complete code, but let's make
it as less pseudo as possible. Pasting lines 386-390 to a dev console throws an
error. It would be more useful if I can paste it and see |obj| successfully
defined.

[Dan Beam, 2016/11/30 23:08:54]

var foo = 1;
var bar = 2;
var o = {foo, bar};
console.log(o);  // {foo: 1, bar: 2}

[Dan Beam, 2016/12/07 19:41:38]

Done.

+
+// Method property
+var obj = {
+  foo() {...},
+  bar() {...}
+}

[Dan Beam, 2016/11/30 23:08:54]

var clearSky = {
  // basically the same as clouds: function() { return 0; }
  clouds() { return 0; },
  color() { return 'blue'; },
};
console.log(clearSky.color());  // 'blue'
console.log(clearSky.clouds());  // 0

[Dan Beam, 2016/12/07 19:41:39]

Done.

+```
+
+**Documentation:** [link](http://www.ecma-international.org/ecma-262/6.0
+/#sec-object-initialiser)
+
+**Discussion Notes / Link to Thread:**
+
+---
+
+## Template Literals
+
+Expression interpolation for Strings, with the ability to access raw template
+pieces.
+
+**Usage Example:**
+
+``` js
+// Simple example
+var greeting = 'hello';
+var myName = {first: 'Foo', last: 'Bar'};
+var message = `${greeting},
+my name is ${myName.first + myName.last}`;
+// message == 'hello,\nmy name is FooBar'
+
+// Custom interpolation
+function foo (strings, ...values) {

[Dan Beam, 2016/11/30 23:08:54]

function foo (
drop space  ^

[Dan Beam, 2016/12/07 19:41:40]

Done.

+  // for foo`bar${42}baz`...
+    // strings[0] === 'bar';
+    // strings[1] === 'baz';
+    // values[0] === 42;
+
+  return strings[1] + strings[0] + values[0];
+}
+
+var newString = foo`bar${42}baz`; // 'bazbar42'

[Dan Beam, 2016/11/30 23:08:53]

can you just drop the last 2 examples (and just keep the hello my name is
example)

[Dan Beam, 2016/12/07 19:41:39]

Done.

+```
+
+**Documentation:** [link](http://www.ecma-international.org/ecma-262/6.0
+/#sec-template-literals)
+
+**Discussion Notes / Link to Thread:**
+
+---
+
+## Binary & Octal Literals
+
+**Usage Example:**
+
+``` js
+0b111110111 === 503;
+0o767 === 503;
+```
+
+**Documentation:** [link](http://www.ecma-international.org/ecma-262/6.0
+/#sec-literals-numeric-literals)
+
+**Discussion Notes / Link to Thread:**
+
+---
+
+## `/u` Unicode Regex Literal
+
+**Usage Example:**
+
+``` js
+'𠮷'.match(/./u)[0].length === 2;
+```
+
+**Documentation:** [link](http://www.ecma-international.org/ecma-262/6.0
+/#sec-get-regexp.prototype.sticky)
+
+**Discussion Notes / Link to Thread:**
+
+---
+
+## `\u{}` Unicode String
+
+**Usage Example:**
+
+``` js
+'\u{1d306}' == '\ud834\udf06'; // true
+```
+
+**Documentation:** [link](http://www.ecma-international.org/ecma-262/6.0
+/#sec-literals-string-literals)
+
+**Discussion Notes / Link to Thread:**
+
+---
+
+## `/y` Regex Sticky Matching
+
+Keep the matching position sticky between matches and this way support
+efficient parsing of arbitrary long input strings, even with an arbitrary

[Dan Beam, 2016/11/30 23:08:53]

arbitrarily long input strings?

[Dan Beam, 2016/12/07 19:41:39]

Done.

+number of distinct regular expressions.
+
+**Usage Example:**
+
+``` js
+var re = new RegExp('yy', 'y');
+re.lastIndex = 3;
+var result = re.exec('xxxyyxx')[0];
+result === 'yy' && re.lastIndex === 5; // true

[Dan Beam, 2016/11/30 23:08:54]

i don't understand this example

+```
+
+**Documentation:** [link](http://es6-features.org
+/#RegularExpressionStickyMatching)
+
+**Discussion Notes / Link to Thread:**
+
+---
+
+## Destructuring Assignment
+
+Flexible destructuring of collections or parameters.
+
+**Usage Example:**
+
+``` js
+// Array
+var list = [ 1, 2, 3 ];

[Dan Beam, 2016/11/30 23:08:53]

note: our ES5 style guide requires no spaces around [array] or {object}
literals.  please update every [ ... ] to [...] and { ... } to {...} throughout
this guide

[Dan Beam, 2016/12/07 19:41:39]

Done.

+var [ a, , b ] = list;

[Dan Beam, 2016/11/30 23:08:52]

var [a, , b] = [1, 2, 3];  // a = 1, b = 3

[Dan Beam, 2016/12/07 19:41:39]

Done.

+// a = 1, b = 3
+
+// Object
+var {width, height, area: a} = rect;

[Dan Beam, 2016/11/30 23:08:54]

define these variables

[Dan Beam, 2016/12/07 19:41:39]

Done.

+// width = rect.width, height = rect.height, a = rect.area
+
+// Parameters
+function f ([ name, val ]) {
+  console.log(name, val);
+}
+function g ({ name: n, val: v }) {
+  console.log(n, v);
+}
+function h ({ name, val }) {
+  console.log(name, val);
+}
+
+f([ 'bar', 42 ]);
+g({ name: 'foo', val:  7 });
+h({ name: 'bar', val: 42 });

[Dan Beam, 2016/11/30 23:08:53]

put the definition and the call of these functions closer together

function f(...) {
}
f()

function g(...) {
}
g(...)

[Dan Beam, 2016/12/07 19:41:39]

Done.

+
+```
+
+**Documentation:** [link](http://www.ecma-international.org/ecma-262/6.0
+/#sec-destructuring-assignment)
+
+**Discussion Notes / Link to Thread:**
+
+---
+
+## Modules
+
+Support for exporting/importing values from/to modules without global
+namespace pollution.
+
+**Usage Example:**
+
+``` js
+// lib/rect.js
+export function getArea() {...};
+export { width, height, unimportant };
+
+// app.js
+import {getArea, width, height} from 'lib/rect';
+
+```
+
+**Documentation:** [link](http://www.ecma-international.org/ecma-262/6.0
+/#sec-modules)
+
+**Discussion Notes / Link to Thread:**
+
+---
+
+## Symbol Type
+
+Unique and immutable data type to be used as an identifier for object
+properties.
+
+**Usage Example:**
+
+``` js
+const foo = Symbol();
+const bar = Symbol();
+typeof foo === 'symbol'; // true
+typeof bar === 'symbol'; // true
+let obj = {};
+obj[foo] = 'foo';
+obj[bar] = 'bar';
+JSON.stringify(obj); // {}
+Object.keys(obj); // []
+Object.getOwnPropertyNames(obj); // []
+Object.getOwnPropertySymbols(obj); // [ foo, bar ]
+```
+
+**Documentation:** [link](http://www.ecma-international.org/ecma-262/6.0
+/#sec-symbol-constructor)
+
+**Discussion Notes / Link to Thread:**
+
+---
+
+## `for ...of` Loops
+
+Convenient operator to iterate over all values of an iterable object.

[Dan Beam, 2016/11/30 23:08:53]

does this include own keys?  as in: can we explain how this is this different
from for ( in )?

[Dan Beam, 2016/12/07 19:41:39]

Done.

+
+**Usage Example:**
+
+``` js
+// Given an iterable  collection `fibonacci`...
+for (let n of fibonacci) {

[Dan Beam, 2016/11/30 23:08:53]

nit: can you use var instead of let in this example?

[Dan Beam, 2016/12/07 19:41:39]

Done.

+  console.log(n);
+}
+```
+
+**Documentation:** [link](http://www.ecma-international.org/ecma-262/6.0
+/#sec-for-in-and-for-of-statements)
+
+**Discussion Notes / Link to Thread:**
+
+---
+
+## Object Static Methods
+
+**Usage Example:**
+
+``` js
+// Object.assign
+var o = Object.assign({a:true}, {b:true}, {c:true});
+'a' in o && 'b' in o && 'c' in o; // true
+
+// Object.setPrototypeOf
+Object.setPrototypeOf({}, Array.prototype) instanceof Array; //true
+
+// Object.is
+// Object.getOwnPropertySymbols
+```
+
+**Documentation:** [link](http://www.ecma-international.org/ecma-262/6.0
+/#sec-properties-of-the-object-constructor)
+
+**Discussion Notes / Link to Thread:**
+
+---
+
+## String Static & Prototype methods
+
+**Usage Example:**
+
+``` js
+// String.raw
+// String.fromCodePoint
+
+// String.prototype.codePointAt
+// String.prototype.normalize
+// String.prototype.repeat
+// String.prototype.startsWith
+// String.prototype.endsWith
+// String.prototype.includes
+```
+
+**Documentation:** [link](http://www.ecma-international.org/ecma-262/6.0
+/#sec-properties-of-the-string-constructor)
+
+**Discussion Notes / Link to Thread:**
+
+---
+
+## Array Static & Prototype Methods
+
+**Usage Example:**
+
+``` js
+// Array.from
+// Array.of
+
+// Array.prototype.copyWithin
+// Array.prototype.find
+// Array.prototype.findIndex
+// Array.prototype.fill
+// Array.prototype.keys
+// Array.prototype.values
+// Array.prototype.entries
+```
+
+**Documentation:** [link](http://www.ecma-international.org/ecma-262/6.0
+/#sec-properties-of-the-array-constructor)
+
+**Discussion Notes / Link to Thread:**
+
+---
+
+## Number Properties
+
+**Usage Example:**
+
+``` js
+// Number.isFinite
+// Number.isInteger
+// Number.isSafeInteger
+// Number.isNaN
+// Number.EPSILON
+// Number.MIN_SAFE_INTEGER
+// Number.MAX_SAFE_INTEGER
+```
+
+**Documentation:** [link](http://www.ecma-international.org/ecma-262/6.0
+/#sec-isfinite-number)
+
+**Discussion Notes / Link to Thread:**
+
+---
+
+## Iterators
+
+**Usage Example:**
+
+``` js
+let fibonacci = {
+  [Symbol.iterator]() {
+    let pre = 0, cur = 1;
+    return {
+      next () {
+        [ pre, cur ] = [ cur, pre + cur ];
+        return { done: false, value: cur };
+      }
+    };
+  }
+};
+```
+
+**Documentation:** [link]()
+
+**Discussion Notes / Link to Thread:**
+
+---
+
+## Generators
+
+Special iterators with specified pausing points.
+
+**Usage Example:**
+
+``` js
+function* range(start, end, step) {
+  while (start < end) {
+    yield start;
+    start += step;
+  }
+}
+
+for (let i of range(0, 10, 2)) {
+  console.log(i); // 0, 2, 4, 6, 8
+}
+
+```
+
+**Documentation:** [link](http://www.ecma-international.org/ecma-262/6.0
+/#sec-generator-function-definitions)
+
+**Discussion Notes / Link to Thread:**
+
+---
+
+## `Map`
+
+**Usage Example:**
+
+``` js
+var key = {};
+var map = new Map();
+

[dpapad, 2016/11/23 01:39:38]

Let's boost this example to be a bit more descriptive.

var map = new Map();
map.size === 0; // true
map.get('foo'); // undefined

var key = {};
map.set(key, 123);
map.size === 1; // true
map.has(key); // true
map.get(key); // 123

map.delete(key);
map.has(key); // false;
map.size === 0; // true

[Dan Beam, 2016/11/30 23:08:53]

agreed

[Dan Beam, 2016/12/07 19:41:39]

Done.

+map.set(key, 123);
+
+map.has(key) && map.get(key) === 123; // true
+```
+
+**Documentation:** [link](http://www.ecma-international.org/ecma-262/6.0
+/#sec-map-objects)
+
+**Discussion Notes / Link to Thread:**
+
+---
+
+## `Set`
+
+**Usage Example:**
+
+``` js
+var obj = {};

[dpapad, 2016/11/23 01:39:38]

obj is not used in this example.

[Dan Beam, 2016/12/07 19:41:39]

Done.

+var set = new Set();
+
+set.add(123);
+set.add(123);

[dpapad, 2016/11/23 01:39:38]

set.size == 1; // true

[Dan Beam, 2016/11/30 23:08:53]

agreed

[Dan Beam, 2016/12/07 19:41:40]

Done.

+
+set.has(123); // true
+```
+
+**Documentation:** [link](http://www.ecma-international.org/ecma-262/6.0
+/#sec-set-objects)
+
+**Discussion Notes / Link to Thread:**
+
+---
+
+## `WeakMap`
+
+WeakMap does not prevent garbage collection if nothing else refers to an object
+within the collection.
+
+**Usage Example:**
+
+``` js
+var key = {};
+var weakmap = new WeakMap();
+
+weakmap.set(key, 123);
+
+weakmap.has(key) && weakmap.get(key) === 123; // true
+```
+
+**Documentation:** [link](http://www.ecma-international.org/ecma-262/6.0
+/#sec-weakmap-objects)
+
+**Discussion Notes / Link to Thread:**
+
+---
+
+## `WeakSet`
+
+WeakSet does not prevent garbage collection if nothing else refers to an object
+within the collection.
+
+**Usage Example:**
+
+``` js
+var obj1 = {};
+var weakset = new WeakSet();
+
+weakset.add(obj1);
+weakset.add(obj1);
+
+weakset.has(obj1); // true
+```
+
+**Documentation:** [link](http://www.ecma-international.org/ecma-262/6.0
+/#sec-weakset-objects)
+
+**Discussion Notes / Link to Thread:**
+
+---
+
+## Typed Arrays
+
+A lot of new typed Arrays...
+
+**Usage Example:**
+
+``` js
+new Int8Array();
+new UInt8Array();
+new UInt8ClampedArray()

[Dan Beam, 2016/11/30 23:08:53]

nit: new UInt8ClampedArray();

[Dan Beam, 2016/12/07 19:41:40]

Done.

+// ...You get the idea. Click on the Documentation link below to see all.
+```
+
+**Documentation:** [link](http://www.ecma-international.org/ecma-262/6.0
+/#sec-typedarray-objects)
+
+**Discussion Notes / Link to Thread:**
+
+---
+
+## `Proxy`
+
+Hooking into runtime-level object meta-operations.
+
+**Usage Example:**
+
+``` js
+let target = {
+  foo: 'Welcome, foo'
+};
+let proxy = new Proxy(target, {
+  get (receiver, name) {
+    return name in receiver ? receiver[name] : `Hello, ${name}`;
+  }
+});

[Dan Beam, 2016/11/30 23:08:53]

var keyTracker = new Proxy({}, {
  keysCreated: 0,

  get (receiver, key) {
    if (key in receiver) {
      console.log('key already exists');
    } else {
      ++this.keysCreated;
      console.log(this.keysCreated + ' keys created!');
      receiver[key] = true;
    }
  },
});

keyTracker.key1;  // 1 keys created!
keyTracker.key1;  // key already exists
keyTracker.key2;  // 2 keys created!

[Dan Beam, 2016/12/07 19:41:39]

Done.

+proxy.foo === 'Welcome, foo'; // true
+proxy.world === 'Hello, world'; // true
+```
+
+**Documentation:** [link](http://www.ecma-international.org/ecma-262/6.0
+/#sec-proxy-object-internal-methods-and-internal-slots)
+
+**Discussion Notes / Link to Thread:**
+
+---
+
+## `Reflection`
+
+Make calls corresponding to the object meta-operations.
+
+**Usage Example:**
+
+``` js
+let obj = { a: 1 };
+Object.defineProperty(obj, 'b', { value: 2 });
+obj[Symbol('c')] = 3;
+Reflect.ownKeys(obj); // ['a', 'b', Symbol(c)]
+```
+
+**Documentation:** [link](http://www.ecma-international.org/ecma-262/6.0
+/#sec-reflection)
+
+**Discussion Notes / Link to Thread:**
+
+---
+
+## Math Methods
+
+A lot of new Math methods.
+
+**Usage Example:**
+
+``` js
+// See Doc
+```
+
+**Documentation:** [link](http://www.ecma-international.org/ecma-262/6.0
+/#sec-math)
+
+**Discussion Notes / Link to Thread:**
+
+---