GlueGun

This is a README FROM THE FUTURE, in that it described the workflow for something that doesn't exist yet.

Write once, Rust anywhere

GlueGun is a project for authoring pure-Rust libraries that can be integrated into any language on any operating system or environment. GlueGun can help you...

  • publish a cross-language API usable from Java/Kotlin, Python, Swift, JavaScript, C, C++, and Go (and adding more languages is easy);
  • package up common code for use across mobile devices.

GlueGun is highly configurable. The core GlueGun project includes several backends but it's easy to write your own -- or use backends written by others and published to crates.io.

GlueGun in 30s

Imagine you have a hello-world Rust crate that you want to expose it to other languages:

#![allow(unused)]
fn main() {
pub fn greet(name: String) -> String {
    format!("Hello, {name}!")
}
}

With GlueGun, you just run

> cargo gluegun java

to create a hello-world-java crate. You can then run

> cargo run -p hello-world-java -- jar

and it will create a target/hello-world.jar file for you to distribute. Java users can then just run hello_world.Functions.greet("Duke").

Java not enough for you? Try

> cargo gluegun python
> carun run -p gluegun-py -- publish

and you will create a Python wrapper and publish it to PyPI. Pretty cool! Not enough for you? Gluegun ships with support for a bunch of languages.

But wait, there's more!

GlueGun is designed to get you up and going as quickly as possible, but it's infinitely customizable. Perhaps you want to make a Java version that does things a bit different? Or you want to integrate with your internal build system at work? No problem at all.

GlueGun uses the same idiom as git and cargo to support extensibility. When you run cargo gluegun foo, gluegun will search for a gluegun-foo executable, installing one from crates.io if needed. This executable is tasked with creating the adapted cratebased on the interface definition that gluegun extracts from your Rust source.

GlueGun is a kind of "meta project":

  • The core GlueGun parses your Rust code to extract the interface, represented in Interface Definition Language.
  • It then invokes a separate executable to map that IDL to some other language:
    • The GlueGun repository includes a number of languages, but you can make your own just by creating a new crate and uploading it to crates.io. No need to centrally coordinate.

Interesting?