addon-sdk/source/lib/sdk/util/iteration.js@6474c204b198 (annotated)
addon-sdk/source/lib/sdk/util/iteration.js
Wed, 31 Dec 2014 06:09:35 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Wed, 31 Dec 2014 06:09:35 +0100
- changeset 0
- 6474c204b198
- permissions
- -rw-r--r--
Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.
| michael@0 | 1 | /* This Source Code Form is subject to the terms of the Mozilla Public |
| michael@0 | 2 | * License, v. 2.0. If a copy of the MPL was not distributed with this |
| michael@0 | 3 | * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ |
| michael@0 | 4 | 'use strict'; |
| michael@0 | 5 | |
| michael@0 | 6 | module.metadata = { |
| michael@0 | 7 | "stability": "experimental" |
| michael@0 | 8 | }; |
| michael@0 | 9 | |
| michael@0 | 10 | // This is known as @@iterator in the ES6 spec. Until it is bound to |
| michael@0 | 11 | // some well-known name, find the @@iterator object by expecting it as |
| michael@0 | 12 | // the first property accessed on a for-of iterable. |
| michael@0 | 13 | const iteratorSymbol = (function() { |
| michael@0 | 14 | try { |
| michael@0 | 15 | for (var _ of Proxy.create({get: function(_, name) { throw name; } })) |
| michael@0 | 16 | break; |
| michael@0 | 17 | } catch (name) { |
| michael@0 | 18 | return name; |
| michael@0 | 19 | } |
| michael@0 | 20 | throw new TypeError; |
| michael@0 | 21 | })(); |
| michael@0 | 22 | |
| michael@0 | 23 | exports.iteratorSymbol = iteratorSymbol; |
| michael@0 | 24 | |
| michael@0 | 25 | // An adaptor that, given an object that is iterable with for-of, is |
| michael@0 | 26 | // suitable for being bound to __iterator__ in order to make the object |
| michael@0 | 27 | // iterable in the same way via for-in. |
| michael@0 | 28 | function forInIterator() { |
| michael@0 | 29 | for (let item of this) |
| michael@0 | 30 | yield item; |
| michael@0 | 31 | } |
| michael@0 | 32 | |
| michael@0 | 33 | exports.forInIterator = forInIterator; |
