3.5 KiB


A new, efficient implementation of Syndicate for JavaScript in both node.js and the browser. The implementation techniques herein are the subject of a forthcoming paper.


Option 1. Create a new program/library using Syndicate/js.

Use npx @syndicate-lang/create DIRECTORY or npm init @syndicate-lang DIRECTORY:

npm init @syndicate-lang myprogram
cd myprogram
npm i .
npm run build
node lib/index.js

Option 2. Add Syndicate/js to an existing program/library.

Install a few packages from the @syndicate-lang scope on

npm i --save-dev @syndicate-lang/syntax @babel/preset-env
npm i --save @syndicate-lang/core

Then, add the @syndicate-lang/syntax/plugin to your .babelrc. Use npx syndicate-babel in place of npx babel to compile your code.

Creating a new Syndicate/js project

Create a skeletal package.json:

  "main": "lib/index.js",
  "scripts": {
    "build": "npx syndicate-babel src --out-dir lib",
    "clean": "rm -rf lib"

The entry point will be lib/index.js; the corresponding source file will be src/index.js.

Two npm run scripts are defined: one which compiles Syndicate/js source files in src to plain JavaScript in lib. The compiler uses Babel; we will configure Babel next.

Create a .babelrc file:

  "presets": [ "@babel/preset-env" ],
  "plugins": [ "@syndicate-lang/syntax/plugin" ]

Now, install the necessary dependencies. Babel and the Syndicate/js extensions are needed at build-time:

npm i --save-dev @syndicate-lang/syntax @babel/preset-env

The Syndicate/js runtime and as many drivers as you would like to use are needed at run-time:

npm i --save @syndicate-lang/core
npm i --save @syndicate-lang/driver-timer

Finally, create the main program file. Create a directory src, and then a file src/index.js:

const { TimeLaterThan } = activate require("@syndicate-lang/driver-timer");

spawn named 'ticker' {
  field this.counter = 0;
  field this.deadline = +(new Date());

  on start { console.log('ticker starting'); }
  on stop  { console.log('ticker stopping'); }

  on asserted TimeLaterThan(this.deadline) {
    console.log('tick', new Date(), this.counter);
    this.deadline += 1000;

  stop on (this.counter == 5);

Now, compile the project:

npm run build

Finally, run the program:

node lib/index.js

The output should be something like:

ticker starting
tick 2018-11-05T14:23:27.713Z 1
tick 2018-11-05T14:23:28.705Z 2
tick 2018-11-05T14:23:29.706Z 3
tick 2018-11-05T14:23:30.706Z 4
tick 2018-11-05T14:23:31.707Z 5
ticker stopping


@syndicate-lang, an implementation of Syndicate for JS.
Copyright (C) 2016-2021 Tony Garnock-Jones

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see