groupWith.ts

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

import type { PH, Predicate2 } from './utils/types.ts';
import curryN from './utils/curry_n.ts';
import { slice } from './slice.ts';

// @types
type GroupWith_2<L extends T[] | string, T> = (functor: L) => L[];

type GroupWith_1<L extends T[] | string, T> = (predicate: Predicate2<T>) => L[];

type GroupWith =
  & (<L extends T[] | string, T>(predicate: Predicate2<T>) => GroupWith_2<L, T>)
  & (<L extends T[] | string, T>(
    predicate: PH,
    functor: L,
  ) => GroupWith_1<L, T>)
  & (<L extends T[] | string, T>(predicate: Predicate2<T>, functor: L) => L[]);

function _groupWith<L extends T[] | string, T>(
  predicate: Predicate2<T | string>,
  functor: L,
) {
  const result: T[][] | string[] = [];
  const len = functor.length;
  let i = 0;
  while (i < len) {
    let j = i + 1;
    while (j < len && predicate(functor[j - 1], functor[j])) j++;
    result.push(slice(i, j, functor) as T[] & string);
    i = j;
  }
  return result;
}

export const groupWith = curryN(2, _groupWith) as GroupWith;