@monstermann/fn/dist/set/addOr.js

A utility library for TypeScript.

import { dfdlT } from "@monstermann/dfdl";
import { cloneSet } from "@monstermann/remmi";

//#region src/set/addOr.ts
/**
* `addOr(target, value, or)`
*
* Adds a `value` to the `target` set and returns a new set. If the value already exists in the set, returns the `or` value instead.
*
* ```ts
* addOr(new Set([1, 2]), 3, null); // Set([1, 2, 3])
* addOr(new Set([1, 2]), 2, null); // null
* ```
*
* ```ts
* pipe(new Set([1, 2]), addOr(3, null)); // Set([1, 2, 3])
* pipe(new Set([1, 2]), addOr(2, null)); // null
* ```
*/
const addOr = dfdlT((target, value, or) => {
	if (target.has(value)) return or;
	const result = cloneSet(target);
	result.add(value);
	return result;
}, 3);

//#endregion
export { addOr };