Static Runtimes

Since the runtime must be mutable, and cannot be safely sent between threads, it can be tricky to use it in a static context.

To this end, rustyscript includes the static_runtime module:

use rustyscript::{static_runtime, RuntimeOptions, Error};

// Can have the default options
static_runtime!(MY_DEFAULT_RUNTIME);

// Or you can provide your own
static_runtime!(MY_CUSTOM_RUNTIME, {
    let mut options = RuntimeOptions::default();
    options.timeout = std::time::Duration::from_secs(5);
    options
});

fn main() -> Result<(), Error> {
    MY_DEFAULT_RUNTIME::with(|runtime| {
        runtime.eval::<()>("console.log('Hello, World!')")
    })
}

Under the hood, a static runtime is effectively:

#![allow(unused)]
fn main() {
thread_local! {
    static MY_RUNTIME: OnceCell<RefCell<Result<Runtime, Error>>>;
}
}

Which provides thread safety, static initialization, interior mutability, and initializer error handling.

Note: While it is possible to initialize a StaticRuntime object directly, it is not recommended, as it bypasses the thread_local safety layer.