| # fast-levenshtein - Levenshtein algorithm in Javascript |
| |
| [](http://travis-ci.org/hiddentao/fast-levenshtein) |
| [](https://badge.fury.io/js/fast-levenshtein) |
| [](https://www.npmjs.com/package/fast-levenshtein) |
| [](https://twitter.com/hiddentao) |
| |
| An efficient Javascript implementation of the [Levenshtein algorithm](http://en.wikipedia.org/wiki/Levenshtein_distance) with locale-specific collator support. |
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| ## Features |
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| * Works in node.js and in the browser. |
| * Better performance than other implementations by not needing to store the whole matrix ([more info](http://www.codeproject.com/Articles/13525/Fast-memory-efficient-Levenshtein-algorithm)). |
| * Locale-sensitive string comparisions if needed. |
| * Comprehensive test suite and performance benchmark. |
| * Small: <1 KB minified and gzipped |
| |
| ## Installation |
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| ### node.js |
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| Install using [npm](http://npmjs.org/): |
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| ```bash |
| $ npm install fast-levenshtein |
| ``` |
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| ### Browser |
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| Using bower: |
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| ```bash |
| $ bower install fast-levenshtein |
| ``` |
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| If you are not using any module loader system then the API will then be accessible via the `window.Levenshtein` object. |
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| ## Examples |
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| **Default usage** |
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| ```javascript |
| var levenshtein = require('fast-levenshtein'); |
| |
| var distance = levenshtein.get('back', 'book'); // 2 |
| var distance = levenshtein.get('我愛你', '我叫你'); // 1 |
| ``` |
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| **Locale-sensitive string comparisons** |
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| It supports using [Intl.Collator](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Collator) for locale-sensitive string comparisons: |
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| ```javascript |
| var levenshtein = require('fast-levenshtein'); |
| |
| levenshtein.get('mikailovitch', 'Mikhaïlovitch', { useCollator: true}); |
| // 1 |
| ``` |
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| ## Building and Testing |
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| To build the code and run the tests: |
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| ```bash |
| $ npm install -g grunt-cli |
| $ npm install |
| $ npm run build |
| ``` |
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| ## Performance |
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| _Thanks to [Titus Wormer](https://github.com/wooorm) for [encouraging me](https://github.com/hiddentao/fast-levenshtein/issues/1) to do this._ |
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| Benchmarked against other node.js levenshtein distance modules (on Macbook Air 2012, Core i7, 8GB RAM): |
| |
| ```bash |
| Running suite Implementation comparison [benchmark/speed.js]... |
| >> levenshtein-edit-distance x 234 ops/sec ±3.02% (73 runs sampled) |
| >> levenshtein-component x 422 ops/sec ±4.38% (83 runs sampled) |
| >> levenshtein-deltas x 283 ops/sec ±3.83% (78 runs sampled) |
| >> natural x 255 ops/sec ±0.76% (88 runs sampled) |
| >> levenshtein x 180 ops/sec ±3.55% (86 runs sampled) |
| >> fast-levenshtein x 1,792 ops/sec ±2.72% (95 runs sampled) |
| Benchmark done. |
| Fastest test is fast-levenshtein at 4.2x faster than levenshtein-component |
| ``` |
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| You can run this benchmark yourself by doing: |
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| ```bash |
| $ npm install |
| $ npm run build |
| $ npm run benchmark |
| ``` |
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| ## Contributing |
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| If you wish to submit a pull request please update and/or create new tests for any changes you make and ensure the grunt build passes. |
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| See [CONTRIBUTING.md](https://github.com/hiddentao/fast-levenshtein/blob/master/CONTRIBUTING.md) for details. |
| |
| ## License |
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| MIT - see [LICENSE.md](https://github.com/hiddentao/fast-levenshtein/blob/master/LICENSE.md) |