# `rebar3_cargo`
This plugin for [`rebar3`](https://www.rebar3.org/) 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.
Todo:
- 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, "https://github.com/rusterlium/rebar3_cargo", {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.
