jsjoins

jsjoins

A JavaScript concurrency library based on the join calculus.

The join calculus is a formal model for message passing concurrency. The name comes from its most powerful feature: join patterns (also known as chords). In the join calculus, programs do not actively request to receive a messages on a certain channel. Instead, they use join patterns, which declaratively specify reactions to specific message patterns (much like method declarations in object-oriented programming). The power of join patterns is that they can be used to atomically process messages from multiple channels.

This project includes a library implementation of join patterns (see src/index.js), as well as a JavaScript syntax extension for declaring channels and join patterns (see src/joinjs.ohm and src/joinjs.js).

Usage

Creating channels:

var joins = require('jsjoins');
var mySyncChannel = joins.Channel();
var myAsyncChannel = joins.AsyncChannel();

Sending messages:

mySyncChannel('hello!');
mySyncChannel({description: 'whatever'});

myAsyncChannel.send('hello!');
myAsyncChannel.send(99);

Join patterns:

joins.when(mySyncChannel).do(function() {
  console.log('simple handler');
});

joins.when(mySyncChannel).and(myAsyncChannel).do(function() {
  return 'value returned to synchronous send';
});