expand-brackets

What is expand-brackets?

The expand-brackets npm package is used to expand and parse bracket expressions in strings. It is particularly useful for handling patterns in strings that involve brackets, such as character classes in regular expressions.

What are expand-brackets's main functionalities?

Expand Bracket Expressions

This feature allows you to expand bracket expressions into their constituent characters. For example, the expression '[a-c]' is expanded into ['a', 'b', 'c'].

const expandBrackets = require('expand-brackets');
console.log(expandBrackets('[a-c]')); // Output: ['a', 'b', 'c']

Handle Negated Bracket Expressions

This feature handles negated bracket expressions, expanding them while preserving the negation symbol. For example, '[^a-c]' is expanded into ['^', 'a', 'b', 'c'].

const expandBrackets = require('expand-brackets');
console.log(expandBrackets('[^a-c]')); // Output: ['^', 'a', 'b', 'c']

Custom Bracket Expansion

This feature allows for custom expansion of bracket expressions based on options provided. For example, using the option { expand: true } with '[a-c]' results in ['a', 'b', 'c'].

const expandBrackets = require('expand-brackets');
console.log(expandBrackets('[a-c]', { expand: true })); // Output: ['a', 'b', 'c']

Other packages similar to expand-brackets

braces

The braces package is used for expanding and parsing brace expressions. It offers more comprehensive functionality for handling complex brace patterns, including nested and sequential expansions. Compared to expand-brackets, braces provides a broader range of pattern expansions.

micromatch

Micromatch is a powerful globbing library that supports advanced matching features, including brace and bracket expansions. It is more versatile than expand-brackets, as it can handle a wide variety of glob patterns and matching rules.

minimatch

Minimatch is a lightweight library for matching file paths against glob patterns. It includes support for bracket and brace expansions, making it a good alternative to expand-brackets for file path matching and pattern expansion.

README

expand-brackets

Expand POSIX bracket expressions (character classes) in glob patterns.

Install

Install with npm:

$ npm install --save expand-brackets

Install with yarn:

$ yarn add expand-brackets

Usage

var brackets = require('expand-brackets');
brackets(string[, options]);

Params

The main export is a function that takes the following parameters:

• pattern {String}: the pattern to convert
• options {Object}: optionally supply an options object
• returns {String}: returns a string that can be used to create a regex

Example

console.log(brackets('[![:lower:]]'));
//=> '[^a-z]'

API

brackets

Parses the given POSIX character class pattern and returns a string that can be used for creating regular expressions for matching.

Params

• pattern {String}
• options {Object}
• returns {Object}

.match

Takes an array of strings and a POSIX character class pattern, and returns a new array with only the strings that matched the pattern.

Params

• arr {Array}: Array of strings to match
• pattern {String}: POSIX character class pattern(s)
• options {Object}
• returns {Array}

Example

const brackets = require('expand-brackets');
console.log(brackets.match(['1', 'a', 'ab'], '[[:alpha:]]'));
//=> ['a']

console.log(brackets.match(['1', 'a', 'ab'], '[[:alpha:]]+'));
//=> ['a', 'ab']

.isMatch

Returns true if the specified string matches the given brackets pattern.

Params

• string {String}: String to match
• pattern {String}: Poxis pattern
• options {String}
• returns {Boolean}

Example

const brackets = require('expand-brackets');

console.log(brackets.isMatch('a.a', '[[:alpha:]].[[:alpha:]]'));
//=> true
console.log(brackets.isMatch('1.2', '[[:alpha:]].[[:alpha:]]'));
//=> false

.matcher

Takes a POSIX character class pattern and returns a matcher function. The returned function takes the string to match as its only argument.

Params

• pattern {String}: Poxis pattern
• options {String}
• returns {Boolean}

Example

const brackets = require('expand-brackets');
const isMatch = brackets.matcher('[[:lower:]].[[:upper:]]');

console.log(isMatch('a.a'));
//=> false
console.log(isMatch('a.A'));
//=> true

.makeRe

Create a regular expression from the given pattern.

Params

• pattern {String}: The pattern to convert to regex.
• options {Object}
• returns {RegExp}

Example

const brackets = require('expand-brackets');
const re = brackets.makeRe('[[:alpha:]]');
console.log(re);
//=> /^(?:[a-zA-Z])$/

.create

Parses the given POSIX character class pattern and returns an object with the compiled output and optional source map.

Params

• pattern {String}
• options {Object}
• returns {Object}

Example

const brackets = require('expand-brackets');
console.log(brackets('[[:alpha:]]'));
// { options: { source: 'string' },
//   input: '[[:alpha:]]',
//   state: {},
//   compilers:
//    { eos: [Function],
//      noop: [Function],
//      bos: [Function],
//      not: [Function],
//      escape: [Function],
//      text: [Function],
//      posix: [Function],
//      bracket: [Function],
//      'bracket.open': [Function],
//      'bracket.inner': [Function],
//      'bracket.literal': [Function],
//      'bracket.close': [Function] },
//   output: '[a-zA-Z]',
//   ast:
//    { type: 'root',
//      errors: [],
//      nodes: [ [Object], [Object], [Object] ] },
//   parsingErrors: [] }

Options

options.sourcemap

Generate a source map for the given pattern.

Example

var res = brackets('[:alpha:]', {sourcemap: true});

console.log(res.map);
// { version: 3,
//   sources: [ 'brackets' ],
//   names: [],
//   mappings: 'AAAA,MAAS',
//   sourcesContent: [ '[:alpha:]' ] }

POSIX Character classes

The following named POSIX bracket expressions are supported:

• [:alnum:]: Alphanumeric characters (a-zA-Z0-9])
• [:alpha:]: Alphabetic characters (a-zA-Z])
• [:blank:]: Space and tab ([ t])
• [:digit:]: Digits ([0-9])
• [:lower:]: Lowercase letters ([a-z])
• [:punct:]: Punctuation and symbols. ([!"#$%&'()*+, -./:;<=>?@ [\]^_``{|}~])
• [:upper:]: Uppercase letters ([A-Z])
• [:word:]: Word characters (letters, numbers and underscores) ([A-Za-z0-9_])
• [:xdigit:]: Hexadecimal digits ([A-Fa-f0-9])

See posix-character-classes for more details.

Not supported

• equivalence classes are not supported
• POSIX.2 collating symbols are not supported

Changelog

v4.0.0

Breaking changes

• Snapdragon was updated to 0.12. Other packages that integrate expand-brackets need to also use snapdragon 0.12.
• Minimum Node.JS version is now version 4.

v3.0.0

Breaking changes

• Snapdragon was updated to 0.11. Other packages that integrate expand-brackets need to also use snapdragon 0.11.

v2.0.0

Breaking changes

• The main export now returns the compiled string, instead of the object returned from the compiler

Added features

• Adds a .create method to do what the main function did before v2.0.0

v0.2.0

In addition to performance and matching improvements, the v0.2.0 refactor adds complete POSIX character class support, with the exception of equivalence classes and POSIX.2 collating symbols which are not relevant to node.js usage.

Added features

• parser is exposed, so that expand-brackets parsers can be used by upstream parsers (like micromatch)
• compiler is exposed, so that expand-brackets compilers can be used by upstream compilers
• source maps

source map example

var brackets = require('expand-brackets');
var res = brackets('[:alpha:]');
console.log(res.map);

{ version: 3,
     sources: [ 'brackets' ],
     names: [],
     mappings: 'AAAA,MAAS',
     sourcesContent: [ '[:alpha:]' ] }

About

Related projects

• braces: Bash-like brace expansion, implemented in JavaScript. Safer than other brace expansion libs, with complete support… more | homepage
• extglob: Extended glob support for JavaScript. Adds (almost) the expressive power of regular expressions to glob… more | homepage
• micromatch: Glob matching for javascript/node.js. A drop-in replacement and faster alternative to minimatch and multimatch. | homepage
• nanomatch: Fast, minimal glob matcher for node.js. Similar to micromatch, minimatch and multimatch, but complete Bash… more | homepage

Contributing

Pull requests and stars are always welcome. For bugs and feature requests, please create an issue.

Contributors

Commits	Contributor
69	jonschlinkert
13	danez
2	MartinKolarik
2	es128
1	doowb
1	eush77
1	mjbvz

Building docs

(This project's readme.md is generated by verb, please don't edit the readme directly. Any changes to the readme must be made in the .verb.md readme template.)

To generate the readme, run the following command:

$ npm install -g verbose/verb#dev verb-generate-readme && verb

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:

$ npm install && npm test

Author

Jon Schlinkert

• github/jonschlinkert
• twitter/jonschlinkert

License

Copyright © 2018, Jon Schlinkert. Released under the MIT License.

This file was generated by verb-generate-readme, v0.6.0, on April 30, 2018.

Changelog

v4.0.0

Breaking changes

• Snapdragon was updated to 0.12. Other packages that integrate expand-brackets need to also use snapdragon 0.12.
• Minimum Node.JS version is now version 4.