// Rust range syntax variants
// let len = s.len();
// &s[0..5] == &s[0..=4]
// &s[6..11] == &s[0..=10]
// &s[0..2] == &s[..2]
// &s[3..len] == &s[3..]
// &s[0..len] == &s[..]
fn main() {
    let my_string = String::from("hello world");

    // first_word works on slices of `String`s
    let word = first_word(&my_string[..]);

    println!("the first word is: {}", word);

    let my_string_literal = "hello world";

    // first_word works on slices of string literals
    let word = first_word(&my_string_literal[..]);

    println!("the first word is: {}", word);

    // Because string literals *are* string slices already,
    // this works too, without the slice syntax!
    let word = first_word(my_string_literal);

    println!("the first word is: {}", word);
}

// &str accepts both String and str, String type and slices
fn first_word(s: &str) -> &str {
    let bytes = s.as_bytes(); // String to array of bytes

    // enumerate takes the value of iter and returns a tuple for each index
    for (i, &item) in bytes.iter().enumerate() {
        if item == b' ' {
            return &s[0..i]; // Return the slice from 0 to i-1
        }
    }

    &s[..] // Return a slice equal to the input string
}