The Error class used when get or send are aborted before completion.

Channel

InvalidTransitionError

The Error class used when an invalid transition is performed.

SendOnClosedError

The Error class used when the send transition is performed on a closed channel.

time.Ticker

A Ticker holds a channel that delivers “ticks” of a clock at intervals.

time.Timer

UnreachableError

Variables

defaultBroadcastSendMode

pipe.otherTopics

time.after

after waits for the duration to elapse and then sends the current time on the returned channel. It is equivalent to (new Timer(d)).c. If efficiency is a concern, use new Timer() instead and call Timer.stop if the timer is no longer needed.

time.tick

tick is a convenience wrapper for new Ticker(d) providing access to the ticking channel only. While tick is useful for clients that have no need to shut down the Ticker, be aware that without a way to shut it down the underlying Ticker cannot be recovered by the garbage collector; it "leaks".

time.timeout

timeout creates a channel that will close after duration milliseconds.

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 });
}

isBroadcastSendMode
isSelectOperation
isSelectSendOperation
merge
pipe.duplicate
pipe.filter
pipe.flat
pipe.flatMap
pipe.forEach
pipe.groupBy
pipe.map
pipe.reduce
pipe.subscribe
select
tagged.select	A tagged-template version of select.

BroadcastChannelOptions
ChannelOptions	Extra options for new channels.
ClosedReceiver
pipe.ChannelDuplicateOptions
pipe.ChannelPipeOptions	Options for pipe operations.
SelectOptions	Extra options used for the `select` function.

BroadcastChannelPipeOptions
BroadcastSendMode
BroadcastSubscribeOptions
Closer
pipe.ChannelDuplicateSendMode
pipe.SubscribeOptions
pipe.SubscribeReturnType
Receiver
SelectDefaultResult
SelectGetOperation
SelectOperation
SelectOperationResult
SelectResult
SelectSendOperation
Sender
Subscribable
tagged.SelectHandler
tagged.SelectOperation

Namespaces

Classes

Enums