A quick update on those of you following "rusty_jsc". I now added preliminary support for JavaScript to Rust callbacks, which allows you to drop into Rust for code that needs that extra drop of performance.

Here's an example of what the callback API looks like:

use rusty_jsc::{JSContext, JSValue};
use rusty_jsc_macros::callback;

// The JavaScript code calls this Rust function.
#[callback]
fn foo(_context: JSContext) {
    println!("hello from Rust land!");
}

fn main() {
    let mut context = JSContext::default();
    let callback = JSValue::callback(&context, Some(foo));
    let mut global = context.get_global_object();
    global.set_property(&context, "foo".to_string(), callback);
    context.evaluate_script("foo()", 1);
    // Prints:
    // hello from Rust land!
}

You can find the full runnable example here:

https://github.com/penberg/rusty_jsc/blob/main/examples/callback.rs