TS Range

range.ts

// No idea why this isn't stdlib
export function range(start: number, stop: number, step: number = 1): number[] {
  if (!Number.isFinite(start) || !Number.isFinite(stop) || !Number.isFinite(step)) {
    throw new TypeError("range(start, stop, step): start/stop/step must be finite numbers");
  }
  if (!Number.isInteger(start) || !Number.isInteger(stop) || !Number.isInteger(step)) {
    throw new TypeError("range(start, stop, step): start/stop/step must be integers");
  }
  if (step === 0) {
    throw new RangeError("range(start, stop, step): step must not be 0");
  }

  const result: number[] = [];

  if (step > 0) {
    for (let n = start; n <= stop; n += step) result.push(n);
  } else {
    for (let n = start; n >= stop; n += step) result.push(n);
  }

  return result;
}