Neon

A safe Rust abstraction layer for native Node.js modules.

Neon protects all handles to the JavaScript heap, even when they're allocated on the Rust stack, ensuring that objects are always safely tracked by the garbage collector.

Getting started

Install neon-cli as a global npm package:

npm install -g neon-cli

To create a new Neon project, use neon new:

neon new my-project

This will ask you a few questions and then generate a project skeleton for you. Follow the instructions from there to build and run your project!

Requirements

So far Neon is only working on OS X. You'll need XCode, Node v4 or later, and Rust 1.5 or later.

A Taste...

A Neon function takes a Call object and produces either a handle to a value or the Throw constant (meaning a JS exception was thrown). The Call object provides access to a memory management scope, which safely manages the rooting of handles to heap objects:

fn make_an_array(call: Call) -> JS<Array> {
    let scope = call.scope; // the current scope for rooting handles
    let array: Handle<Array> = Array::new(scope, 3);
    try!(array.set(0, Integer::new(scope, 9000)));
    try!(array.set(1, Object::new(scope)));
    try!(array.set(2, Number::new(scope, 3.14159)));
    Ok(array)
}

For a more complete demonstration, try building a hello world with neon new, or check out the slightly bigger word count demo.

Get Involved

The Neon community is just getting started and there's tons of fun to be had. Come play! :)

The Rust Bridge community Slack is open to all; use the Slackin app to receive an invitation.

There's also an IRC channel at #neon on Mozilla IRC (irc.mozilla.org).

Known Limitations

• I've only gotten this working on OS X.
• Currently, downstream clients of a native Rust module have to have Rust installed on their system in order to build it.
• There's no way to fallback on precompiled or portable implementations.

I would love to work with people on fixing these limitations!

License

MIT