Iter Helpers

Requires Node.js 22 or newer.

Composable operators for synchronous and asynchronous iterators in TypeScript: map, filter, batch, concurrentMap, mux, a back-pressured Fifo and more, chained fluently with chain().

Installation

pnpm add @harnyk/iter-helpers

npm install @harnyk/iter-helpers and yarn add @harnyk/iter-helpers work as well. The package ships ESM and CommonJS builds with type definitions.

Quick start

import { chain, range } from "@harnyk/iter-helpers";

const result = await chain(range(1, 6))
    .map((n) => n * 2)
    .skip(1)
    .take(3)
    .toArray();
// => [4, 6, 8]

chain() accepts anything you can iterate with for await: an array, a generator or an async generator. Every method of the chain applies an operator and returns a new chain. Chains are lazy: nothing is read from the source until you consume the chain with toArray(), consume() or for await.

Documentation

Guides, the list of operators, error handling, diagrams and the API reference are at https://harnyk.github.io/iter-helpers/.

License

MIT