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diff --git a/node_modules/regexpu-core/README.md b/node_modules/regexpu-core/README.md new file mode 100644 index 000000000..1f80cd89d --- /dev/null +++ b/node_modules/regexpu-core/README.md @@ -0,0 +1,62 @@ +# regexpu-core [](https://travis-ci.org/mathiasbynens/regexpu-core) [](https://coveralls.io/r/mathiasbynens/regexpu-core) [](https://gemnasium.com/mathiasbynens/regexpu-core) + +_regexpu_ is a source code transpiler that enables the use of ES6 Unicode regular expressions in JavaScript-of-today (ES5). + +_regexpu-core_ contains _regexpu_’s core functionality, i.e. `rewritePattern(pattern, flag)`, which enables rewriting regular expressions that make use of [the ES6 `u` flag](https://mathiasbynens.be/notes/es6-unicode-regex) into equivalent ES5-compatible regular expression patterns. + +## Installation + +To use _regexpu-core_ programmatically, install it as a dependency via [npm](https://www.npmjs.com/): + +```bash +npm install regexpu-core --save-dev +``` + +Then, `require` it: + +```js +const rewritePattern = require('regexpu-core'); +``` + +## API + +This module exports a single function named `rewritePattern`. + +### `rewritePattern(pattern, flags)` + +This function takes a string that represents a regular expression pattern as well as a string representing its flags, and returns an ES5-compatible version of the pattern. + +```js +rewritePattern('foo.bar', 'u'); +// → 'foo(?:[\\0-\\t\\x0B\\f\\x0E-\\u2027\\u202A-\\uD7FF\\uDC00-\\uFFFF]|[\\uD800-\\uDBFF][\\uDC00-\\uDFFF]|[\\uD800-\\uDBFF])bar' + +rewritePattern('[\\u{1D306}-\\u{1D308}a-z]', 'u'); +// → '(?:[a-z]|\\uD834[\\uDF06-\\uDF08])' + +rewritePattern('[\\u{1D306}-\\u{1D308}a-z]', 'ui'); +// → '(?:[a-z\\u017F\\u212A]|\\uD834[\\uDF06-\\uDF08])' +``` + +_regexpu-core_ can rewrite non-ES6 regular expressions too, which is useful to demonstrate how their behavior changes once the `u` and `i` flags are added: + +```js +// In ES5, the dot operator only matches BMP symbols: +rewritePattern('foo.bar'); +// → 'foo(?:[\\0-\\t\\x0B\\f\\x0E-\\u2027\\u202A-\\uFFFF])bar' + +// But with the ES6 `u` flag, it matches astral symbols too: +rewritePattern('foo.bar', 'u'); +// → 'foo(?:[\\0-\\t\\x0B\\f\\x0E-\\u2027\\u202A-\\uD7FF\\uDC00-\\uFFFF]|[\\uD800-\\uDBFF][\\uDC00-\\uDFFF]|[\\uD800-\\uDBFF])bar' +``` + +`rewritePattern` uses [regjsgen](https://github.com/d10/regjsgen), [regjsparser](https://github.com/jviereck/regjsparser), and [regenerate](https://github.com/mathiasbynens/regenerate) as internal dependencies. + +## Author + +| [](https://twitter.com/mathias "Follow @mathias on Twitter") | +|---| +| [Mathias Bynens](https://mathiasbynens.be/) | + +## License + +_regexpu-core_ is available under the [MIT](https://mths.be/mit) license. |