use rhai::{packages::*, Engine, EvalAltResult, INT}; fn main() -> Result<(), Box<EvalAltResult>> { let mut engine = Engine::new_raw(); engine.load_package(ArithmeticPackage::new().get()); let result = engine.eval::<INT>("40 + 2")?; println!("Answer: {}", result); // prints 42 Ok(()) }