Rustler

Documentation | Getting Started | Example

Rustler is a library for writing Erlang NIFs in safe Rust code. That means there should be no ways to crash the BEAM (Erlang VM). The library provides facilities for generating the boilerplate for interacting with the BEAM, handles encoding and decoding of Erlang terms, and catches rust panics before they unwind into C.

The library provides functionality for both Erlang and Elixir, however Elixir is favored as of now.

Features:

• Safety - The code you write in a Rust NIF should never be able to crash the BEAM.
• Interop - Decoding and encoding rust values into Erlang terms is as easy as a function call.
• Type composition - Making a Rust struct encodable and decodable to Erlang or Elixir can be done with a single attribute.
• Resource objects - Enables you to safely pass a reference to a Rust struct into Erlang code. The struct will be automatically dropped when it's no longer referenced.

Getting started

The easiest way of getting started, is using the Mix project generator.

• Run mix archive.install https://github.com/hansihe/rustler_archives/raw/master/rustler_installer.ez to install the tool.
• Run mix rustler.new <path> and follow the instructions.

NOTE: At the moment you need Rust nightly-2016-05-07. With multirust, you need to run multirust override nightly-2016-05-07 in the generated project directory for things to work as expected.

How it looks like

This is the code for a minimal NIF that adds two numbers and returns the result. ```rust

![feature(plugin)]

![plugin(rustler_codegen)]

[macro_use]

extern crate rustler; use rustler::{ NifEnv, NifTerm, NifResult, NifEncoder };

rustlerexportnifs!( "Elixir.TestNifModule", [("add", 2, add)], None );

fn add<'a>(env: &'a NifEnv, args: &Vec) -> NifResult> { let num1: i64 = try!(args[0].decode()); let num2: i64 = try!(args[1].decode()); Ok((num1 + num2).encode(env)) } ```

License

Licensed under either of

• Apache License, Version 2.0, (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.