@cprecioso/async-iterable-helpers

Lazy, composable helpers for working with sync and async iterables. Wrap any iterable, build a pipeline of transforms, and consume it with a sink. Nothing is evaluated until a sink runs, and mapping, filtering, and reducing functions may all be async.

Similar to RxJS, but treated as ordered sequences of values rather than streams of events, and implicitly unwrapping Promises.

Install

npm install @cprecioso/async-iterable-helpers

Usage

Start with a creator to get a Wrapper, chain .pipe() calls to transform the sequence, and finish with .sink() to consume it:

import { from, filter, map, toArray } from "@cprecioso/async-iterable-helpers";

const result = await from([1, 2, 3, 4])
  .pipe(filter((n) => n % 2 === 0))
  .pipe(map(async (n) => n * 10))
  .sink(toArray());

// result: [20, 40]

A Wrapper is itself an AsyncIterable, so you can also use it directly with for await:

for await (const n of from([1, 2, 3]).pipe(map((n) => n * 2))) {
  console.log(n); // 2, 4, 6
}

API

Check the API reference at https://cprecioso.github.io/async-iterable-helpers/