# `rebar3_cargo`

This plugin for [`rebar3`]( enables the automatic building of Rust crates in an Erlang application.
The plugin will build all crates in the `crates` directory and copy all binary outputs to `priv/crates/<cratename>/<version>/<release-mode>/<binary>`.
See the test application in this repository for an example of a port program and NIF module implemented in Rust.

## Todo list

As of this writing `rebar3_cargo` will build crates on
linux and passes tests, however it is still under construction.

- allow cargo/rust compile flags
- `--target` flag handling
- Appveyor CI
- maybe external crate support using cargo clone

# Using the plugin
Use the plugin by adding the following to `rebar.config`:

``` erlang
{plugins, [
    { rebar3_cargo, ".*", {git, "", {branch, "master"}}}

{provider_hooks, [
    {pre, [
        {compile, {cargo, build}}
    {post, [
        {clean, {cargo, clean}},
        {eunit, {cargo, test}}

This will automatically download and use `rebar3_cargo`.  Crates will be compiled whenever the containing app is compiled.
The cargo `--release` switch will be used when the `prod` profile is active.  For example:

``` sh
rebar3 as prod compile

# Application structure with Rust crates
To add crates to an Erlang application, place them in a `crates/` folder, and reference them in a Cargo Workspace.  All crates found within will be built and resulting artifacts will be placed in the `priv/crates/` folder.