#![feature(generator_trait, generators)]
use std::ops::{Generator, GeneratorState};

pub fn main() {
    let mut g = move || {
        'a: while {yield return 'a: while {break 'a; true} {}; true} {yield}
    };

    let mut n = 0;
    unsafe {
        loop {
            n += 1;
            if n == 10 { break }
            match g.resume() {
                GeneratorState::Yielded(y) => println!("YIELD {:?}", y),
                GeneratorState::Complete(r) => { println!("RETURNED {:?}", r); break},
            }
        }
    }
}