mimas
mimas is a statically typed, embeddable scripting language for Rust. It carries over much of Rust's syntax and ergonomics, reshaping the rest to deliver what a scripting layer is good for: fast iteration, logic you can change without a rebuild, and a runtime that ships anywhere your program runs.
Static typing with inference, user-defined types, exhaustive pattern matching, and more of the same features that empower you in Rust.
let area: float? = match my_shape {
Shape::Circle(r) => r * r * std::math::PI,
Shape::Rectangle(w, h) => w * h,
_ => null,
};Rigorous, not rigid. Strong inference lets you focus on your goals, not your types. Writing is intuitive, and sub-second compile times keep you in motion.
let nums = [5, 3, 8, 1];
let big = for n in nums { if n > 4 collect n; };
print(f"found {big.len()}: {big}"); // -> found 2: [5, 8]Stay fast. Static analysis fuels the VM, putting mimas at the front of the pure-Rust scripting runtimes. See the benchmarks for more.
physics struct field access, float math
| mimas | 928ms |
|---|---|
| fabricator | 2.29s |
| rune | 2.81s |
| boa | 3.75s |
| koto | 6.06s |
| steel | 6.56s |
| dyon | 8.37s |
| rustpython | 10.88s |
| rhai | 12.68s |
Pure-Rust runtimes, measured on an AMD Ryzen 7 9800X3D running Linux. mimas v0.1.0 · Rhai (perf) v1.26.0 · Rune v0.14.2 · Koto v0.16.1 · Dyon v0.51.2 · Steel v0.8.3 · Boa v0.22.0 · RustPython v0.5.0 · Fabricator git cef73ca
Share your Rust types and functions with the mimas macro, all while maintaining type safety. The macro alone is all you need for mimas to find it.
// rust
#[mimas]
struct User(String);
#[mimas]
impl User {
fn greet(self) {
println!("Hello, {}!", self.0);
}
}// mimas
let user = User("mimas");
user.greet(); // Hello, mimas!- Guaranteed “Results” – mimas treats any panic as a bug, both in the compiler and the VM.
- Tested top to bottom – over 1,700 tests cover every corner of the codebase. Even the tests are tested, thanks to cargo mutants.
- Helpful diagnostics – bugs are caught at their source with clear reports powered by miette:
error: non-exhaustive match ╭─[tools/src/main.mim:3:1] 2 │ 3 │ ╭─▶ match Color::random() { 4 │ │ Color::Red => print("Red!"), 5 │ │ Color::Blue => print("Blue!"), 6 │ ├─▶ } · ╰──── missing pattern `Color::Green` 7 │ ╰──── ╰─▶ advice: `Color::Green` defined here ╭─[tools/src/color.mim:6:5] 5 │ Blue, 6 │ Green, · ──┬── · ╰── this variant has no matching arm 7 │ } ╰────