uhwait

A simple async/await gadget that adds seamless message passing to JavaScript.

npm install uhwait

Requires node.js >= v8.9.0. Previous versions of node have an incomplete version of the async_hooks implementation that will not work.

Usage

uhwait is not intended to be used in a practical way, it's was written primarily to educate developers about message passing, actors, and concurrency.

uhwait provides spawn, self, and receive semantics, that when used with async/await (kind of) emulate the behaviour of erlang.

On top of those primitives, the pid object returned by spawn provides pid.send(...args) to send a message to the process, and pid.join() to wait until a process exits.

An actor's 'process' context is fully managed through subsequent async continuations, regardless of nesting. join will properly wait until there are no more continuations remaining. See examples/helloworld.js for details.

const { self, receive, spawn } = require('uhwait');

async function hello() {
  const [msg] = await receive();
  console.log('hello', msg);
  hello();
}

async function watcher(pid) {
  await pid.join();
  console.log(`pid ${pid.id} exited with ${pid.exit_reason}`);
}

const hello = spawn(hello);
spawn(watcher, [hello]);
hello.send('world');
hello.send('world!!');

See examples/ for more.