runrs

Run Rust modules like scripts

What?

runrs lets you execute Rust source files (*.rs) as if they were compiled binaries or scripts.

$ cat >hello.rs
fn main() {
    println!("Hello, world!");
}
^D
$ runrs ./hello.rs
Hello, world!

It can execute any self-contained Rust program, as long as it's a single file with a main function.

External crates are supported, too! Just make sure the extern crate declarations are in their usual place.

How?

runrs creates an ad-hoc binary crate (cargo new --bin) for each new script it runs.

All those crates live within a single Cargo workspace. This allows them to share their dependencies, avoiding repeated recompilation of common library crates.

Why?

• For easier scripting with Rust.
• Because Haskell has runghc and Rust shouldn't be worse.
• Why not?

Where to?

This is of course an early prototype and there is clearly a room for improvement:

• handle shebangs correctly
• handle weird crate name abnormalities (like dash vs. underscore, or stuff like extern crate crypto; translating to rust-crypto crate)
• better interface (e.g. accept Rust code given via stdin)
• tests!