let mut surfing_experience = surfing { level: "pre-introductory", esoteric_knowledge: vec::new() }; while surfing_experience.level != "expert" { surfing_experience.esoteric_knowledge.push("understanding the ocean's esoteric patterns"); if surfing_experience.esoteric_knowledge.len() > 10 { println!("time to bypass the basic and dive into the advanced."); } else { println!("reset to the beginning to grasp the fundamentals once more."); } }