@push-stream-std/push-concat-map-eager (0.0.4)

Published 2026-07-19 23:31:25 +00:00 by Dvorak

Set up this registry in your project .npmrc file:

@push-stream-std:registry=https://hub.kl1.tenere.ai/api/packages/push-stream-std/npm/

To install the package using npm, run the following command:

npm install @push-stream-std/push-concat-map-eager@0.0.4

or add it to the package.json file:

"@push-stream-std/push-concat-map-eager": "0.0.4"

For more information on the npm registry, see the documentation.

push-concat-map-eager

Like flatMap but with eager inner stream execution.

Published as @push-stream-std/push-concat-map-eager.

Synopsis

import concatMapEager from '@push-stream-std/push-concat-map-eager';

const eager = concatMapEager(x => [x * 2, x * 2 + 1], { concurrency: 4 });

source.pipe(eager).pipe(sink);

// Input:  1, 2, 3
// Output: 2, 3, 4, 5, 6, 7

Install

npm config set @push-stream-std:registry https://hub.kl1.tenere.ai/api/packages/push-stream-std/npm/
npm config set -- //hub.kl1.tenere.ai/api/packages/push-stream-std/npm/:_authToken "$PACKAGE_TOKEN"
npm install @push-stream-std/push-concat-map-eager

Description

A through stream that maps each input value via a mapper function and flattens the result. Inner push-stream results are started eagerly up to a configurable concurrency limit, but emitted results maintain the original input order via indexed buffering. Static values (arrays or scalars) are emitted inline. More efficient than sequential concatMap for I/O-bound work. Uses a head pointer pattern for amortized O(1) queue operations.

API

`concatMapEager(mapper, options)`

Creates an eager concat-map through stream.

mapper (value) => result – Function called for each input value. May return a push-stream source (has pipe()), an array, or a scalar value.
options object (optional):
- concurrency number (default Infinity) – Maximum number of inner streams to run concurrently. Additional inputs are queued until an inner stream completes.
Returns A through stream with pipe(), write(), end(), abort(), resume(), paused, and ended.

Tests

npm test

Tests cover mapping and flattening arrays, concurrency limit enforcement (max active streams), order preservation with array-returning mappers, empty source producing no output, and mapper returning simple scalar values (non-array, non-stream).

Requirements

Node.js 18 or later. ESM only.

License

MIT

push-stream stream concatMap flatMap map parallel

Details

npm

2026-07-19 23:31:25 +00:00

0

MIT

4.0 KiB

Assets (1)

push-concat-map-eager-0.0.4.tgz 4.0 KiB

Versions (5) View all

0.0.7

2026-07-21

0.0.6

2026-07-20

0.0.5

2026-07-20

0.0.4

2026-07-19

0.0.3