1 | [![NPM version](https://img.shields.io/npm/v/esprima.svg)](https://www.npmjs.com/package/esprima)
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2 | [![npm download](https://img.shields.io/npm/dm/esprima.svg)](https://www.npmjs.com/package/esprima)
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3 | [![Build Status](https://img.shields.io/travis/jquery/esprima/master.svg)](https://travis-ci.org/jquery/esprima)
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4 | [![Coverage Status](https://img.shields.io/codecov/c/github/jquery/esprima/master.svg)](https://codecov.io/github/jquery/esprima)
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5 |
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6 | **Esprima** ([esprima.org](http://esprima.org), BSD license) is a high performance,
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7 | standard-compliant [ECMAScript](http://www.ecma-international.org/publications/standards/Ecma-262.htm)
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8 | parser written in ECMAScript (also popularly known as
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9 | [JavaScript](https://en.wikipedia.org/wiki/JavaScript)).
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10 | Esprima is created and maintained by [Ariya Hidayat](https://twitter.com/ariyahidayat),
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11 | with the help of [many contributors](https://github.com/jquery/esprima/contributors).
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12 |
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13 | ### Features
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14 |
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15 | - Full support for ECMAScript 2017 ([ECMA-262 8th Edition](http://www.ecma-international.org/publications/standards/Ecma-262.htm))
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16 | - Sensible [syntax tree format](https://github.com/estree/estree/blob/master/es5.md) as standardized by [ESTree project](https://github.com/estree/estree)
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17 | - Experimental support for [JSX](https://facebook.github.io/jsx/), a syntax extension for [React](https://facebook.github.io/react/)
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18 | - Optional tracking of syntax node location (index-based and line-column)
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19 | - [Heavily tested](http://esprima.org/test/ci.html) (~1500 [unit tests](https://github.com/jquery/esprima/tree/master/test/fixtures) with [full code coverage](https://codecov.io/github/jquery/esprima))
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20 |
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21 | ### API
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22 |
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23 | Esprima can be used to perform [lexical analysis](https://en.wikipedia.org/wiki/Lexical_analysis) (tokenization) or [syntactic analysis](https://en.wikipedia.org/wiki/Parsing) (parsing) of a JavaScript program.
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24 |
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25 | A simple example on Node.js REPL:
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26 |
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27 | ```javascript
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28 | > var esprima = require('esprima');
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29 | > var program = 'const answer = 42';
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30 |
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31 | > esprima.tokenize(program);
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32 | [ { type: 'Keyword', value: 'const' },
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33 | { type: 'Identifier', value: 'answer' },
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34 | { type: 'Punctuator', value: '=' },
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35 | { type: 'Numeric', value: '42' } ]
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36 |
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37 | > esprima.parseScript(program);
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38 | { type: 'Program',
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39 | body:
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40 | [ { type: 'VariableDeclaration',
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41 | declarations: [Object],
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42 | kind: 'const' } ],
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43 | sourceType: 'script' }
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44 | ```
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45 |
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46 | For more information, please read the [complete documentation](http://esprima.org/doc). |
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