update.ts

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

import { adjust } from './adjust.ts';
import { always } from './always.ts';
import curryN from './utils/curry_n.ts';
import type { InferPrimitive, PH } from './utils/types.ts';

// @types
type Update_1<T> = (index: number) => T[];

type Update_2<T> = (value: T) => T[];

type Update_3<T> = (list: T[]) => T[];

type Update_2_3 =
  & (<T>(value: T) => Update_3<InferPrimitive<T>>)
  & (<T>(value: PH, list: T[]) => Update_2<T>)
  & (<T>(value: T, list: T[]) => T[]);

type Update_1_3<T> =
  & ((index: number) => Update_3<T>)
  & ((index: PH, list: T[]) => Update_1<T>)
  & ((index: number, list: T[]) => T[]);

type Update_1_2<T> =
  & ((index: number) => Update_2<T>)
  & ((index: PH, value: T) => Update_1<T>)
  & ((index: number, value: T) => T[]);

type Update =
  & ((index: number) => Update_2_3)
  & (<T>(index: PH, value: T) => Update_1_3<InferPrimitive<T>>)
  & (<T>(index: PH, value: PH, list: T[]) => Update_1_2<T>)
  & (<T>(index: number, value: T) => Update_3<InferPrimitive<T>>)
  & (<T>(index: number, value: PH, list: T[]) => Update_2<T>)
  & (<T>(index: PH, value: T, list: T[]) => Update_1<T>)
  & (<T>(index: number, value: T, list: T[]) => T[]);

function _update<T>(index: number, value: T, list: T[]) {
  return adjust(index, always(value), list);
}

/**
 * Returns a new array with copy of `list` and `value` replaced at `index`.
 *
 *      Fae.adjust(2, Fae.add(1), [0, 1, 2, 3]) // [0, 1, 3, 3]
 *      Fae.adjust(-3, Fae.add(1), [0, 1, 2, 3]) // [0, 2, 2, 3]
 */
export const update = curryN(3, _update) as Update;