mergeiterator

mergeiterator

Merges async iterators.

Using

This utility is for merging together async iterators.

merge(collection_of_iterables): Iterable

Pass it a collection of iterables and it'll return an async iterator, which will contain all values from those iterables. Those iterables and the collection of them can be arrays, calls to generators, or any other kind of iterable, synchronous or async, finite or infinite.

import merge from "mergeiterator"

async function DoIt() {
	const array = [1,2,3]
	function *generator() {
		let i = 6
		while (true) yield (i++)
	})
	async function *asyncGenerator() {
		yield await Promise.resolve(4)
		yield Promise.resolve(5)
	})
	for await (const v of merge([array, generator(), asyncGenerator()])) {
		console.log(v)
	}
}
// 1 6 2 7 4 3 8 5 9 10 11 ...

mergeIterator function guarantees, that if some value is yielded by some of iterables that mergeIterator is passed, then that value will be eventually yielded by mergeIterator. It also guarantees that the order of values within the same iterable is preserved.

If some iterable yields a promise, its value will be yielded, not a promise itself.

If some iterable throws an error, that error will be redirected to a caller and other iterables will be closed.

API

Table of Contents

• merge
  • Parameters

merge

Merges async or sync iterables into async one.

Parameters

• sequences AnyIterable<AnyIterable<(Promise<Yield> | Yield), any>, Return>

Returns $AsyncIterator<Yield, Return, void>