Usage

range(3); // yields 0, 1, 2, 3
range(0, 3); // yields 0, 1, 2, 3
range(0, 3, "y"); // yields y, y, y, y
range(0, 3, () => "y"); // yields y, y, y, y
range(0, 3, (i) => i); // yields 0, 1, 2, 3
range(0, 3, (i) => `y${i}`); // yields y0, y1, y2, y3
range(0, 3, obj); // yields obj, obj, obj, obj
range(0, 6, (i) => i, 2); // yields 0, 2, 4, 6

Installation

CLI

npx atmx add helper range

Manually

Copy and paste the following method into @/utils/helpers/range.ts:

import { isFunction } from "@/helpers/is-function.ts";

/**
* Creates a generator that will produce an iteration through the
* range of number as requested.
*
* @example
* range(3)                  // yields 0, 1, 2, 3
* range(0, 3)               // yields 0, 1, 2, 3
* range(0, 3, 'y')          // yields y, y, y, y
* range(0, 3, () => 'y')    // yields y, y, y, y
* range(0, 3, i => i)       // yields 0, 1, 2, 3
* range(0, 3, i => `y${i}`) // yields y0, y1, y2, y3
* range(0, 3, obj)          // yields obj, obj, obj, obj
* range(0, 6, i => i, 2)    // yields 0, 2, 4, 6
*/
export function* range<T = number>(
startOrLength: number,
end?: number,
valueOrMapper: T | ((i: number) => T) = (i) => i as T,
step = 1,
): Generator<T> {
const mapper = isFunction(valueOrMapper)
? valueOrMapper
: () => valueOrMapper;
const start = end ? startOrLength : 0;
const final = end ?? startOrLength;
for (let i = start; i <= final; i += step) {
yield mapper(i);
if (i + step > final) {
  break;
}
}
}