Proof of Concept: Calling Rust from R

NOTE: this is just a proof of concept, not a usable crate collection! You have been warned.

Requirements

This project has been tested in the following environment:

• Ubuntu 18.04
• R = 3.6.1
• Rust 1.39.0 (cargo 1.39.0)

Contributions welcome for making this work on other platforms (e.g. Windows).

Usage

r-bindgen provides a procedural attribute macro generating a suitable FFI function for R-Rust-interop:

#[r_bindgen]
pub fn rust_sort(mut v: Vec<i32>) -> Vec<i32> {
    v.sort();
    v
}

Awesome, isn't it?

Playground

Playground contains a Rust crate that produces a shared library.

In R, we just need to load the generated shared library (use crate-type = ["cdylib"] in your Cargo.toml) and .Call the foreign function:

dyn.load("../target/debug/libplayground.so")
v <- sample(1:64, 64)
.Call("rust_sort", v)

You can run the demo from the playground folder using:

cargo build
R -f R/hello.R

Example package

The example folder demonstrates how a Rust crate can be turned into an R package.

If you want to include documentation, run the R prompt from the example folder:

roxygen2::roxygenise()

From the root of the repository, run:

R CMD build example

Then install the package, e.g. using the R REPL:

install.packages("rustexample_0.1.0.tar.gz")
# You may wish to specify the install location using the lib.loc parameter:
# install.packages("rustexample_0.1.0.tar.gz", lib.loc="path/to/R/libraries")

To try the package, run using the R package:

> library("rustexample")
> rust.sort(c(5, 3, 1, 4, 2))
[1] 1 2 3 4 5
> rust.mean(rnorm(64, mean=5, sd=1))
[1] 5.045658

Crate Overview

• example: Example crate/R package which can be installed
• playground: Example loading a shared library directly
• r_bindgen: Procedural macro for generating suitable FFI functions
• r_internals: Generated Rust bindings for Rinternals.h, implementation detail, should not be used directly
• r_interop: Conversion between R and Rust types

License

This project is licensed under either of the following licenses, at your option:

• Apache License Version 2.0
• MIT License