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Exercise - Modules

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Now's your chance to use what you've learned about using modules in functions and visibility.

The following code has a few compiler errors. Your assignment in this exercise is to make the code compile successfully without modifying the main function.

mod text_processing {

    mod letters {
        fn count_letters(text: &str) -> usize {
            text.chars().filter(|ref c| c.is_alphabetic()).count()
        }
    }

    mod numbers {
        fn count_numbers(text: &str) -> usize {
           text.chars().filter(|ref c| c.is_numeric()).count()
        }
    }
}

fn count_letters_and_numbers(text: &str) -> (usize, usize) {
    let number_of_letters = ???;
    let number_of_numbers = ???;
    (number_of_letters, number_of_numbers)
}

fn main() {
    assert_eq!(count_letters_and_numbers("221B Baker Street"), (12, 3));
    assert_eq!(count_letters_and_numbers("711 Maple Street"), (11, 3));
    assert_eq!(count_letters_and_numbers("4 Privet Drive"), (11, 1));
}

You can also view this exercise at this Rust Playground link.

To find a solution for this exercise, check out this Rust Playground link.

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