groups.ts

import type { IObjectOf } from "@thi.ng/api";
import { charRange } from "./range.js";

/** @internal */
const __defGroup = (...ranges: Iterable<string>[]) => {
	const acc: IObjectOf<boolean> = {};
	for (let range of ranges) {
		for (let c of range) {
			acc[c] = true;
		}
	}
	return Object.freeze(acc);
};

/**
 * Object with whitespace characters as keys and their values set to
 * true. All others undefined.
 */
export const WS: IObjectOf<boolean> = Object.freeze({
	"\t": true,
	"\n": true,
	"\v": true,
	"\f": true,
	"\r": true,
	" ": true,
});

/**
 * Object with 0-9 characters as keys and their values set to true. All
 * others undefined.
 */
export const DIGITS = __defGroup(charRange("0", "9"));

/**
 * Object with hex digit characters (upper & lower case versions) as
 * keys and their values set to true. All others undefined.
 */
export const HEX = __defGroup(
	charRange("0", "9"),
	charRange("A", "F"),
	charRange("a", "f")
);

/**
 * Object with ASCII lowercase characters as keys and their values set
 * to true. All others undefined.
 */
export const LOWER = __defGroup(charRange("a", "z"));

/**
 * Object with ASCII uppercase characters as keys and their values set
 * to true. All others undefined.
 */
export const UPPER = __defGroup(charRange("A", "Z"));

/**
 * Combination of {@link UPPER} and {@link LOWER}.
 */
export const ALPHA = Object.freeze({ ...UPPER, ...LOWER });

/**
 * Combination of {@link ALPHA} and {@link DIGITS} and '_'.
 */
export const ALPHA_NUM: IObjectOf<boolean> = Object.freeze({
	...ALPHA,
	...DIGITS,
	_: true,
});

/**
 * Object with ASCII punctuation characters as keys and their values set
 * to true. All others undefined.
 */
export const PUNCTUATION = __defGroup(
	charRange("!", "/"),
	charRange(":", "@"),
	charRange("[", "`"),
	charRange("{", "~")
);