Function raceIterators

test/development/basic/next-rs-api.test.ts:92–109

(iterators: AsyncIterableIterator<T>[])

}

function raceIterators<T>(iterators: AsyncIterableIterator<T>[]) {
  const nexts = iterators.map((iterator, i) =>
    iterator.next().then((next) => ({ next, i }))
  )
  return (async function* () {
    while (true) {
      const remaining = nexts.filter((x) => x)
      if (remaining.length === 0) return
      const { next, i } = await Promise.race(remaining)
      if (!next.done) {
        yield next.value
        nexts[i] = iterators[i].next().then((next) => ({ next, i }))
      } else {
        nexts[i] = undefined
      }
    }
  })()
}

async function* filterMapAsyncIterator<T, U>(
  iterator: AsyncIterableIterator<T>,