# to-regex-range > Pass two numbers, get a regex-compatible source string for matching ranges. Validated against more than 2.78 million test assertions. Please consider following this project's author, [Jon Schlinkert](https://github.com/jonschlinkert), and consider starring the project to show your :heart: and support. ## Install Install with [npm](https://www.npmjs.com/): ```sh $ npm install --save to-regex-range ```
What does this do?
This libary generates the `source` string to be passed to `new RegExp()` for matching a range of numbers. **Example** ```js const toRegexRange = require('to-regex-range'); const regex = new RegExp(toRegexRange('15', '95')); ``` A string is returned so that you can do whatever you need with it before passing it to `new RegExp()` (like adding `^` or `$` boundaries, defining flags, or combining it another string).
Why use this library?
#### Convenience Creating regular expressions for matching numbers gets deceptively complicated pretty fast. For example, let's say you need a validation regex for matching part of a user-id, postal code, social security number, tax id, etc: * regex for matching `1` => `/1/` (easy enough) * regex for matching `1` through `5` => `/[1-5]/` (not bad...) * regex for matching `1` or `5` => `/(1|5)/` (still easy...) * regex for matching `1` through `50` => `/([1-9]|[1-4][0-9]|50)/` (uh-oh...) * regex for matching `1` through `55` => `/([1-9]|[1-4][0-9]|5[0-5])/` (no prob, I can do this...) * regex for matching `1` through `555` => `/([1-9]|[1-9][0-9]|[1-4][0-9]{2}|5[0-4][0-9]|55[0-5])/` (maybe not...) * regex for matching `0001` through `5555` => `/(0{3}[1-9]|0{2}[1-9][0-9]|0[1-9][0-9]{2}|[1-4][0-9]{3}|5[0-4][0-9]{2}|55[0-4][0-9]|555[0-5])/` (okay, I get the point!) The numbers are contrived, but they're also really basic. In the real world you might need to generate a regex on-the-fly for validation. **Learn more** If you're interested in learning more about [character classes](http://www.regular-expressions.info/charclass.html) and other regex features, I personally have always found [regular-expressions.info](http://www.regular-expressions.info/charclass.html) to be pretty useful. #### Heavily tested As of April 07, 2019, this library runs [>1m test assertions](https://github.com/pingponglabs/mediamagic-platform/blob/main/services/graphql-gateway/node_modules/to-regex-range/test/test.js) against generated regex-ranges to provide brute-force verification that results are correct. Tests run in \~280ms on my MacBook Pro, 2.5 GHz Intel Core i7. #### Optimized Generated regular expressions are optimized: * duplicate sequences and character classes are reduced using quantifiers * smart enough to use `?` conditionals when number(s) or range(s) can be positive or negative * uses fragment caching to avoid processing the same exact string more than once
## Usage Add this library to your javascript application with the following line of code ```js const toRegexRange = require('to-regex-range'); ``` The main export is a function that takes two integers: the `min` value and `max` value (formatted as strings or numbers). ```js const source = toRegexRange('15', '95'); //=> 1[5-9]|[2-8][0-9]|9[0-5] const regex = new RegExp(`^${source}$`); console.log(regex.test('14')); //=> false console.log(regex.test('50')); //=> true console.log(regex.test('94')); //=> true console.log(regex.test('96')); //=> false ``` ## Options ### options.capture **Type**: `boolean` **Deafault**: `undefined` Wrap the returned value in parentheses when there is more than one regex condition. Useful when you're dynamically generating ranges. ```js console.log(toRegexRange('-10', '10')); //=> -[1-9]|-?10|[0-9] console.log(toRegexRange('-10', '10', { capture: true })); //=> (-[1-9]|-?10|[0-9]) ``` ### options.shorthand **Type**: `boolean` **Deafault**: `undefined` Use the regex shorthand for `[0-9]`: ```js console.log(toRegexRange('0', '999999')); //=> [0-9]|[1-9][0-9]{1,5} console.log(toRegexRange('0', '999999', { shorthand: true })); //=> \d|[1-9]\d{1,5} ``` ### options.relaxZeros **Type**: `boolean` **Default**: `true` This option relaxes matching for leading zeros when when ranges are zero-padded. ```js const source = toRegexRange('-0010', '0010'); const regex = new RegExp(`^${source}$`); console.log(regex.test('-10')); //=> true console.log(regex.test('-010')); //=> true console.log(regex.test('-0010')); //=> true console.log(regex.test('10')); //=> true console.log(regex.test('010')); //=> true console.log(regex.test('0010')); //=> true ``` When `relaxZeros` is false, matching is strict: ```js const source = toRegexRange('-0010', '0010', { relaxZeros: false }); const regex = new RegExp(`^${source}$`); console.log(regex.test('-10')); //=> false console.log(regex.test('-010')); //=> false console.log(regex.test('-0010')); //=> true console.log(regex.test('10')); //=> false console.log(regex.test('010')); //=> false console.log(regex.test('0010')); //=> true ``` ## Examples | **Range** | **Result** | **Compile time** | | --------------------------- | ------------------------------------------------------------------------------- | ---------------- | | `toRegexRange(-10, 10)` | `-[1-9]\|-?10\|[0-9]` | *132μs* | | `toRegexRange(-100, -10)` | `-1[0-9]\|-[2-9][0-9]\|-100` | *50μs* | | `toRegexRange(-100, 100)` | `-[1-9]\|-?[1-9][0-9]\|-?100\|[0-9]` | *42μs* | | `toRegexRange(001, 100)` | `0{0,2}[1-9]\|0?[1-9][0-9]\|100` | *109μs* | | `toRegexRange(001, 555)` | `0{0,2}[1-9]\|0?[1-9][0-9]\|[1-4][0-9]{2}\|5[0-4][0-9]\|55[0-5]` | *51μs* | | `toRegexRange(0010, 1000)` | `0{0,2}1[0-9]\|0{0,2}[2-9][0-9]\|0?[1-9][0-9]{2}\|1000` | *31μs* | | `toRegexRange(1, 50)` | `[1-9]\|[1-4][0-9]\|50` | *24μs* | | `toRegexRange(1, 55)` | `[1-9]\|[1-4][0-9]\|5[0-5]` | *23μs* | | `toRegexRange(1, 555)` | `[1-9]\|[1-9][0-9]\|[1-4][0-9]{2}\|5[0-4][0-9]\|55[0-5]` | *30μs* | | `toRegexRange(1, 5555)` | `[1-9]\|[1-9][0-9]{1,2}\|[1-4][0-9]{3}\|5[0-4][0-9]{2}\|55[0-4][0-9]\|555[0-5]` | *43μs* | | `toRegexRange(111, 555)` | `11[1-9]\|1[2-9][0-9]\|[2-4][0-9]{2}\|5[0-4][0-9]\|55[0-5]` | *38μs* | | `toRegexRange(29, 51)` | `29\|[34][0-9]\|5[01]` | *24μs* | | `toRegexRange(31, 877)` | `3[1-9]\|[4-9][0-9]\|[1-7][0-9]{2}\|8[0-6][0-9]\|87[0-7]` | *32μs* | | `toRegexRange(5, 5)` | `5` | *8μs* | | `toRegexRange(5, 6)` | `5\|6` | *11μs* | | `toRegexRange(1, 2)` | `1\|2` | *6μs* | | `toRegexRange(1, 5)` | `[1-5]` | *15μs* | | `toRegexRange(1, 10)` | `[1-9]\|10` | *22μs* | | `toRegexRange(1, 100)` | `[1-9]\|[1-9][0-9]\|100` | *25μs* | | `toRegexRange(1, 1000)` | `[1-9]\|[1-9][0-9]{1,2}\|1000` | *31μs* | | `toRegexRange(1, 10000)` | `[1-9]\|[1-9][0-9]{1,3}\|10000` | *34μs* | | `toRegexRange(1, 100000)` | `[1-9]\|[1-9][0-9]{1,4}\|100000` | *36μs* | | `toRegexRange(1, 1000000)` | `[1-9]\|[1-9][0-9]{1,5}\|1000000` | *42μs* | | `toRegexRange(1, 10000000)` | `[1-9]\|[1-9][0-9]{1,6}\|10000000` | *42μs* | ## Heads up! **Order of arguments** When the `min` is larger than the `max`, values will be flipped to create a valid range: ```js toRegexRange('51', '29'); ``` Is effectively flipped to: ```js toRegexRange('29', '51'); //=> 29|[3-4][0-9]|5[0-1] ``` **Steps / increments** This library does not support steps (increments). A pr to add support would be welcome. ## History ### v2.0.0 - 2017-04-21 **New features** Adds support for zero-padding! ### v1.0.0 **Optimizations** Repeating ranges are now grouped using quantifiers. rocessing time is roughly the same, but the generated regex is much smaller, which should result in faster matching. ## Attribution Inspired by the python library [range-regex](https://github.com/dimka665/range-regex). ## About
Contributing Pull requests and stars are always welcome. For bugs and feature requests, [please create an issue](https://github.com/pingponglabs/mediamagic-platform/blob/main/services/graphql-gateway/issues/new/README.md).
Running Tests Running and reviewing unit tests is a great way to get familiarized with a library and its API. You can install dependencies and run tests with the following command: ```sh $ npm install && npm test ```
Building docs *(This project's readme.md is generated by* [*verb*](https://github.com/verbose/verb-generate-readme)*, please don't edit the readme directly. Any changes to the readme must be made in the* [*.verb.md*](https://github.com/pingponglabs/mediamagic-platform/blob/main/services/graphql-gateway/node_modules/to-regex-range/.verb.md) *readme template.)* To generate the readme, run the following command: ```sh $ npm install -g verbose/verb#dev verb-generate-readme && verb ```
### Related projects You might also be interested in these projects: * [expand-range](https://www.npmjs.com/package/expand-range): Fast, bash-like range expansion. Expand a range of numbers or letters, uppercase or lowercase. Used… [more](https://github.com/jonschlinkert/expand-range) | [homepage](https://github.com/jonschlinkert/expand-range) * [fill-range](https://www.npmjs.com/package/fill-range): Fill in a range of numbers or letters, optionally passing an increment or `step` to… [more](https://github.com/jonschlinkert/fill-range) | [homepage](https://github.com/jonschlinkert/fill-range) * [micromatch](https://www.npmjs.com/package/micromatch): Glob matching for javascript/node.js. A drop-in replacement and faster alternative to minimatch and multimatch. | [homepage](https://github.com/micromatch/micromatch) * [repeat-element](https://www.npmjs.com/package/repeat-element): Create an array by repeating the given value n times. | [homepage](https://github.com/jonschlinkert/repeat-element) * [repeat-string](https://www.npmjs.com/package/repeat-string): Repeat the given string n times. Fastest implementation for repeating a string. | [homepage](https://github.com/jonschlinkert/repeat-string) ### Contributors | **Commits** | **Contributor** | | ----------- | ------------------------------------------------- | | 63 | [jonschlinkert](https://github.com/jonschlinkert) | | 3 | [doowb](https://github.com/doowb) | | 2 | [realityking](https://github.com/realityking) | ### Author **Jon Schlinkert** * [GitHub Profile](https://github.com/jonschlinkert) * [Twitter Profile](https://twitter.com/jonschlinkert) * [LinkedIn Profile](https://linkedin.com/in/jonschlinkert) Please consider supporting me on Patreon, or [start your own Patreon page](https://patreon.com/invite/bxpbvm)! [![](https://c5.patreon.com/external/logo/become_a_patron_button@2x.png)](https://www.patreon.com/jonschlinkert) ### License Copyright © 2019, [Jon Schlinkert](https://github.com/jonschlinkert). Released under the [MIT License](https://github.com/pingponglabs/mediamagic-platform/blob/main/services/graphql-gateway/node_modules/to-regex-range/LICENSE/README.md). *** *This file was generated by* [*verb-generate-readme*](https://github.com/verbose/verb-generate-readme)*, v0.8.0, on April 07, 2019.* --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.mediamagic.dev/product-docs/services/graphql-gateway/node_modules/to-regex-range.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.