@monstermann/fn/dist/array/mapEach.js

A utility library for TypeScript.

import { is } from "../function/is.js";
import { dfdlT } from "@monstermann/dfdl";
import { cloneArray } from "@monstermann/remmi";

//#region src/array/mapEach.ts
/**
* `mapEach(array, mapper)`
*
* Applies the `mapper` function to each element in `array`, returning a new array with the mapped elements.
*
* ```ts
* mapEach([1, 2, 3, 4], (x) => x * 2); // [2, 4, 6, 8]
* ```
*
* ```ts
* pipe(
*     [1, 2, 3, 4],
*     mapEach((x) => x * 2),
* ); // [2, 4, 6, 8]
* ```
*/
const mapEach = dfdlT((target, mapper) => {
	let result;
	for (let i = 0; i < target.length; i++) {
		const prev = target[i];
		const next = mapper(prev, i, target);
		if (is(prev, next)) continue;
		result ??= cloneArray(target);
		result[i] = next;
	}
	return result ?? target;
}, 2);

//#endregion
export { mapEach };