my first working neon class

greeter.rs

#[macro_use]
extern crate neon;
extern crate neon_sys;

use neon::mem::Handle;
use neon::vm;
use neon::js::{JsFunction, JsString, Value, Object};
use neon::js::class::{JsClass, Class};

struct Greeter {
    greeting: String
}

declare_class! {
    class JsGreeter for Greeter {
        init(call) {
            let scope = call.scope;
            let greeting = try!(try!(call.arguments.require(scope, 0)).to_string(scope)).value();
            Ok(Greeter {
                greeting: greeting
            })
        }

        method hello(call) {
            let scope = call.scope;
            let name = try!(try!(call.arguments.require(scope, 0)).to_string(scope)).value();
            let msg = vm::lock(call.arguments.this(scope), |greeter| {
                format!("{}, {}!", greeter.greeting, name)
            });
            Ok(try!(JsString::new_or_throw(scope, &msg[..])).upcast())
        }
    }
}

register_module!(m, {
    let class: Handle<JsClass<JsGreeter>> = try!(JsGreeter::class(m.scope));
    let constructor: Handle<JsFunction> = try!(class.constructor(m.scope));
    try!(m.exports.set("Greeter", constructor));
    Ok(())
});