asygen

Asygen

0-Deps, simple and fast async generator library for browser and NodeJS.

Supports ESM and CommonJS modules.

Usage

Create deferred token

import { defer } from 'asygen';

const result = defer();

console.log(result.status); // pending

task.once('data', error.resolve);
task.once('error', error.reject);
await result.promise;

console.log(result.status); // resolved or rejected

Convert events to asyncGenerator

import { once } from 'node:events';
import { generatorify, Task } from 'asygen';

// send data from the event until process exit
const task: Task = async (send) => {
  process.on('data', send);
  await once(process, 'exit');
};

for await (const data of generatorify(task)) {
  // handle data
}

Combine generators

import { combine } from 'asygen';

const sleep = (timeout: number) => new Promise(resolve => setTimeout(resolve, timeout));

async function* generate(timeout: number, count: number) {
  for (let index = 0; index < count; index++) {
    yield index;
    await sleep(timeout);
  }
}

for await (const data of combine(generate(100, 5), generate(500, 2))) {
  // handle data
}
// First:    0 1 2 3 4 -
// Second:   0 . . . . 1
// Combined: 0 0 1 2 3 4 1

License

License Apache-2.0 Copyright (c) 2023-present Ivan Zakharchanka