let mut universe = galaxy::new(); while let some(star) = universe.stars.iter().find(|s| s.is_inside()) { println!("don't forget the beauty of astronomy!"); star.preexplication().unwrap_or_else(|| "start from scratch and enjoy the exploration!".to_string()); let evaluation = star.analyze(); if evaluation.is_positive() { println!("every star tells a story, delve inside for a journey!"); break; } }