Extension with Rust
mimas is designed to live inside a Rust program, and the boundary between the two is meant to be easy to cross: Rust can provide its types, functions, and systems, mimas takes it from there. This chapter covers that boundary – how to expose your Rust code to mimas, what happens to values as they cross, and how to handle the things that can go wrong.
The short version is that a single attribute is usually all it takes:
// rust
#[mimas]
fn roll(sides: i64) -> i64 {
/* ... */
}// mimas
print(roll(20));Nothing about this is dynamic: the signature you write in Rust becomes the signature the mimas compiler enforces at every call site, so a script that misuses your API fails to compile rather than failing at runtime.
The language server checks scripts against your API once your host has run through cargo. See Host APIs.
| Page | Covers |
|---|---|
| Basics | The mimas macro: functions, constants, types, and modules |
| Working With Types | How Rust types map to mimas types, and what each costs |
| Runtime Errors | The ways a native function can fail, recoverably or not |
| Fixtures & Context | How to communicate data from the host into the native functions you provide |
| Freeze | Taking Fixtures a step further and enabling mutable access to the host. |
| Advanced Usage | Registering by hand for the cases the macro can’t infer |