Documentation

# Quick Start

npm install zeroreg

# or
pnpm add zeroreg
yarn add zeroreg
bun add zeroreg

import { digit } from 'zeroreg'

// Match a phone number: 123-456-7890
const phone = digit(3).then('-').then(digit(3)).then('-').then(digit(4))

phone.test('123-456-7890')  // true
phone.toRegex()             // /\d{3}-\d{3}-\d{4}/

import { email, url, phone } from 'zeroreg/patterns'

email.test('hello@world.com')     // true
url.test('https://github.com')    // true
phone.test('+1-234-567-8900')     // true

# Character Classes

Match specific types of characters.

import { digit, letter, charIn, literal } from 'zeroreg'

// Match exactly 3 digits
digit(3).test('123')  // true

// Match a vowel
charIn('aeiou').test('e')  // true

// Match a literal dot (escaped automatically)
literal('.').test('.')  // true

# Quantifiers

Control how many times a pattern matches.

import { digit, letter, optional } from 'zeroreg'

// One or more digits
digit().oneOrMore().test('123')  // true

// Optional plus sign, then digits
optional('+').then(digit().oneOrMore()).test('+123')  // true
optional('+').then(digit().oneOrMore()).test('123')   // true

// Between 2 and 4 letters
letter().between(2, 4).test('abc')  // true

# Groups

Capture parts of your match or group patterns together.

import { capture, digit, oneOf, group, literal } from 'zeroreg'

// Extract year, month, day
const datePattern = capture(digit(4), 'year')
  .then('-')
  .then(capture(digit(2), 'month'))
  .then('-')
  .then(capture(digit(2), 'day'))

const match = '2024-03-15'.match(datePattern.toRegex())
match.groups.year   // '2024'
match.groups.month  // '03'
match.groups.day    // '15'

// Match "cat" or "dog" or "bird"
oneOf('cat', 'dog', 'bird').test('dog')  // true

# Anchors

Match positions in the string, not characters.

# Output Methods

Convert your pattern to different formats and use it.

import { digit } from 'zeroreg'

const pattern = digit().oneOrMore()

// Test if string matches
pattern.test('abc123')  // true

// Get all matches
pattern.matchAll('abc 123 def 456')  // [['123'], ['456']]

// Replace all matches
pattern.replace('abc 123 def 456', 'X')  // 'abc X def X'

// Get native RegExp with flags
pattern.toRegex('gi')  // /\d+/gi

# Pre-built Patterns

Import ready-to-use patterns for common use cases.

import { email, url, phone, date, uuid, ... } from 'zeroreg/patterns'