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71 lines
2.1 KiB
71 lines
2.1 KiB
# es6-symbol |
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## ECMAScript 6 Symbol polyfill |
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For more information about symbols see following links |
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- [Symbols in ECMAScript 6 by Axel Rauschmayer](http://www.2ality.com/2014/12/es6-symbols.html) |
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- [MDN Documentation](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol) |
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- [Specification](http://people.mozilla.org/~jorendorff/es6-draft.html#sec-symbol-constructor) |
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### Limitations |
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Underneath it uses real string property names which can easily be retrieved, however accidental collision with other property names is unlikely. |
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### Usage |
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If you'd like to use native version when it exists and fallback to [ponyfill](https://ponyfill.com) if it doesn't, use *es6-symbol* as following: |
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```javascript |
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var Symbol = require('es6-symbol'); |
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``` |
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If you want to make sure your environment implements `Symbol` globally, do: |
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```javascript |
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require('es6-symbol/implement'); |
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``` |
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If you strictly want to use polyfill even if native `Symbol` exists (hard to find a good reason for that), do: |
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```javascript |
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var Symbol = require('es6-symbol/polyfill'); |
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``` |
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#### API |
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Best is to refer to [specification](http://people.mozilla.org/~jorendorff/es6-draft.html#sec-symbol-objects). Still if you want quick look, follow examples: |
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```javascript |
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var Symbol = require('es6-symbol'); |
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var symbol = Symbol('My custom symbol'); |
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var x = {}; |
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x[symbol] = 'foo'; |
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console.log(x[symbol]); 'foo' |
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// Detect iterable: |
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var iterator, result; |
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if (possiblyIterable[Symbol.iterator]) { |
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iterator = possiblyIterable[Symbol.iterator](); |
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result = iterator.next(); |
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while(!result.done) { |
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console.log(result.value); |
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result = iterator.next(); |
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} |
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} |
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``` |
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### Installation |
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#### NPM |
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In your project path: |
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$ npm install es6-symbol |
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##### Browser |
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To port it to Browser or any other (non CJS) environment, use your favorite CJS bundler. No favorite yet? Try: [Browserify](http://browserify.org/), [Webmake](https://github.com/medikoo/modules-webmake) or [Webpack](http://webpack.github.io/) |
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## Tests [![Build Status](https://travis-ci.org/medikoo/es6-symbol.png)](https://travis-ci.org/medikoo/es6-symbol) |
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$ npm test
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