Create a looooong teeeeext generator

main.rs

use std::iter::repeat;

fn main() {
    println!("{}", long_string(String::from("hello world"), 3));
    println!("{}", long_string(String::from("lol"), 10));
}

/// Create a loooong teeeext generator that takes in a string and an integer `n`,
/// and multiplies the vowels in the string by `n`.
///
/// Example:
///
/// ```
/// let long = long_string(String::from("hello world"), 3)
/// // long == "heeellooo wooorld"
///
/// let long = long_string(String::from("lol"), 10)
/// // long == "looooooooool"
/// ```
fn long_string(s: String, n: usize) -> String {
    let mut r = String::new();
    for c in s.chars() {
        match c {
            'a' | 'e' | 'i' | 'o' | 'u' => {
                for repeated in repeat(c).take(n) {
                    r.push(repeated)
                }
            }
            _ => r.push(c),
        }
    }

    r
}