Async Channels

Channels are queue-like objects (First In First Out) that their enqueue (send) and dequeue (get) functions are asynchronous (async). By passing them between asynchronous functions we can synchronize operations between said functions.

Setup

NodeJS

Released under both npmjs & github packages:

Install:

npm

npm install @eyalsh/async_channels

yarn

yarn add @eyal-shalev/async_channels

import (ES Modules):

import { Channel } from "@eyalsh/async_channels";

require (CommonJS):

const { Channel } = require("@eyalsh/async_channels");

Deno

The library is available to import from deno.land/x/async_channels

import { Channel } from "https://deno.land/x/async_channels/mod.ts";

Browser - CDN / Download

You can import the library from any CDN that mirrors npmjs.com, such as skypack.dev or unpkg.com.

import { Channel } from "https://cdn.skypack.dev/@eyalsh/async_channels";

Or you can download compiled library from GitHub:

import { Channel } from "/path/to/async_channels.esm.js";

Note: an IIFE version also exist, if your application doesn’t support ES modules.

<script src="/path/to/async_channels.iife.js"></script>
<script>
  const {Channel} = async_channels;
</script>

Examples

middleware (ping-pong)
pipeline (even or odd)
pipeline (lorem-ipsum)
Message Queue
static site (todos app)

import { Channel, time } from "https://deno.land/x/async_channels/mod.ts";

function produce(num: number) {
  return Channel.from((async function* () {
    for (let i = 0; i < num; i++) {
      await time.timeout(100).get(); // Do some work...
      yield i;
    }
  })());
}

time.timeout(300).get().then(() => console.log("boo"));

for await (const product of produce(4)) {
  console.log({ product });
}