crazy-parser/src/void.ts

A light-weight parser combinator

import {Parser} from "./index"

export function char(c: string): Parser<undefined>
{
	return new Parser<undefined, Error>((input, state) =>
	{
		if (state.index >= input.length)
			return new Error()

		const char = String.fromCodePoint(input[state.index])

		if (char != c)
			return new Error()

		state.index += 1
	})
}

export function str(s: string): Parser<undefined>
{
	const buffer = Uint32Array.from(Array.from(s).map(c => c.codePointAt(0)))

	return new Parser<undefined, Error>((input, state) =>
	{
		if (state.index + buffer.length > input.length)
			return new Error()

		for (let i = 0; i < buffer.length; i += 1)
			if (input[state.index + i] != buffer[i])
				return new Error()

		state.index += buffer.length
	})
}