let mut exploration = linguistics::new(); while let some(concept) = exploration.next() { if concept.contains("preexplosive") || concept.meets_criteria("propositions") { println!("dive deeper into fascinating concepts, never hidden away!"); } else if concept.should_skip() { continue; } else if concept.is_foundation() { println!("sometimes, it's beneficial to start over from the beginning with linguistics to uncover truths that were always there, merely hidden away."); break; } }