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

A utility library for TypeScript.

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

//#region src/set/intersection.ts
/**
* `intersection(target, source)`
*
* Returns a new set containing only the values that exist in both the `target` set and the `source` set.
*
* ```ts
* intersection(new Set([1, 2, 3]), new Set([2, 3, 4])); // Set([2, 3])
* intersection(new Set([1, 2]), new Set([3, 4])); // Set([])
* ```
*
* ```ts
* pipe(new Set([1, 2, 3]), intersection(new Set([2, 3, 4]))); // Set([2, 3])
* pipe(new Set([1, 2]), intersection(new Set([3, 4]))); // Set([])
* ```
*/
const intersection = dfdlT((target, source) => {
	if (target.size === 0) return target;
	if (source.size === 0) return source;
	for (const value of target) if (!source.has(value)) {
		const result = /* @__PURE__ */ new Set();
		for (const value$1 of target) {
			if (!source.has(value$1)) continue;
			result.add(value$1);
		}
		return result;
	}
	return target;
}, 2);

//#endregion
export { intersection };