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, and consider starring the project to show your :heart: and support.

Install

Install with npm:

``sh
$ npm install --save to-regex-range
`

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

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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])
`

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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}
`

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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

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New features

Adds support for zero-padding!

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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.

About

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You might also be interested in these projects:

* expand-range: Fast, bash-like range expansion. Expand a range of numbers or letters, uppercase or lowercase. Used… more | homepage
* fill-range: Fill in a range of numbers or letters, optionally passing an increment or step to… more | step to use, or create a regex-compatible range with options.toRegex`"" class="text-primary hover:underline" target="_blank" rel="noopener noreferrer">homepage
* micromatch: Glob matching for javascript/node.js. A drop-in replacement and faster alternative to minimatch and multimatch. | homepage
* repeat-element: Create an array by repeating the given value n times. | homepage
* repeat-string: Repeat the given string n times. Fastest implementation for repeating a string. | homepage

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| Commits | Contributor |
| --- | --- |
| 63 | jonschlinkert |
| 3 | doowb |
| 2 | realityking |

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Jon Schlinkert

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Copyright © 2019, Jon Schlinkert.
Released under the MIT License.

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_This file was generated by verb-generate-readme, v0.8.0, on April 07, 2019._