@imhonglu/pattern-builder NPM

@imhonglu/pattern-builder

Introduction

A RegExp builder library that can be used without dependencies.
All patterns are converted to regular expressions through the toRegExp method.

Installation

npm install @imhonglu/pattern-builder

Usage

Here's an example of creating a userinfo pattern from URI Spec.

For detailed usage, please refer to the API Reference.

// constants.ts
import { characterSet, concat, hexDigit } from "@imhonglu/pattern-builder";

// pct-encoded = "%" HEXDIG HEXDIG
export const pctEncoded = concat(
	"%",
	hexDigit.clone().exact(2),
);

// unreserved = ALPHA / DIGIT / "-" / "." / "_" / "~"
export const unreserved = characterSet(
	alpha,
	digit,
	/[\-._~]/,
);

// sub-delims = "!" / "$" / "&" / "'" / "(" / ")"
//            / "*" / "+" / "," / ";" / "="
export const subDelims = characterSet(/[!$&'()*+,;=]/);

// userinfo.ts
import { oneOf, characterSet } from "@imhonglu/pattern-builder";
import { pctEncoded, subDelims, unreserved } from "./constants.js";

const pattern = oneOf(pctEncoded, characterSet(unreserved, subDelims, ":"))
		.nonCapturingGroup()
		.oneOrMore()
	.anchor()
	.toRegExp();

console.log(pattern.test("user:pass")); // true
console.log(pattern.test("@")); // false
console.log(pattern.test("@:@")); // false