zip.ts

// Copyright (c) 2020 Jozty. All rights reserved. MIT license.

import { zipWith } from './zipWith.ts';
import curryN from './utils/curry_n.ts';
import type { PH } from './utils/types.ts';

// @types
type Zip_2<T1> = <T2>(list2: T2[]) => [T1, T2][];

type Zip_1<T2> = <T1>(list1: T1[]) => [T1, T2][];

type Zip =
  & (<T1>(list1: T1[]) => Zip_2<T1>)
  & (<T2>(list1: PH, list2: T2[]) => Zip_1<T2>)
  & (<T1, T2>(list1: T1[], list2: T2[]) => [T1, T2][]);

function _zip<T1, T2>(list1: T1[], list2: T2[]): [T1, T2][] {
  return zipWith((a, b) => [a, b], list1, list2);
}

/**
 * Creates a new list out of two passed lists `list1`, `list2` by pairing up
 * equally-positioned pair in both the lists.
 * The returned is truncated to the length of the shorter of the two input lists.
 *
 *      Fae.zip([100, 200, 300], [1, 2, 3]) // [[1, 100], [2, 200], [3, 300]]
 */
export const zip = curryN(2, _zip) as Zip;