range.ts

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

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

// @types
type Range_2 = (to: number) => number[];

type Range_1 = (from: number) => number[];

type Range =
  & ((from: number) => Range_2)
  & ((from: PH, to: number) => Range_1)
  & ((from: number, to: number) => number[]);

function _range(from: number, to: number) {
  if (
    isNaN(from) ||
    isNaN(to) ||
    !isInteger(from) ||
    !isInteger(to)
  ) {
    throw new Error(
      `The arguments should be finite integer values but got\n\tfrom: ${from}\n\tto: ${to}`,
    );
  }

  const result = [];
  const l = to - from + 1;
  if (l <= 0) return [];
  result.length = l;
  for (let i = 0; i < l; i++) {
    result[i] = from++;
  }
  return result;
}

/** Returns a list of numbers from `from` to `to` **both inclusive**. */
export const range = curryN(2, _range) as Range;