type Stack = Vec<i32>;
type NativeWord = fn(&mut Stack);

enum ForthWord<'a> {
    NativeWord(NativeWord),
    CompiledWord(&'a [ForthWord<'a>])
}

fn plus(stack: &mut Stack) {
    let a = stack.pop().unwrap();
    let b = stack.pop().unwrap();
    stack.push(a + b)
}

fn push1(stack: &mut Stack) {
    stack.push(1)
}

fn main() {
    let push1_word =
}