export async function sleep_ms(ms) {
  await new Promise((resolve) => setTimeout(resolve, ms));
}

export async function map_limit(items, worker) {
  const list = Array.isArray(items) ? items : [];

  const res = new Array(list.length);
  let idx = 0;

  async function run_one() {
    while (idx < list.length) {
      const cur = idx;
      idx += 1;
      res[cur] = await worker(list[cur], cur);
    }
  }

  const runners = [];
  for (let i = 0; i < list.length; i += 1) {
    runners.push(run_one());
  }

  await Promise.all(runners);
  return res;
}