hs-rust-learn 0.1.0

hs's rust test learn
Documentation 
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fn main () {
    let mut s1 = String::from("alibaba");
    let len = calc_length(&mut s1);
    println!("{} length is {}", s1, len);

    // let s2 = s1[..];
    let word_index = find_first_word(&s1);
    println!("{}", word_index);

    let word_index2 = find_first_word("qq 123");
    println!("{}", word_index2);
    // let s2 = s1;
    // s1.clear();

}
fn calc_length(s: &mut String) -> usize {
    s.push_str(" hello");
    s.len()
}

fn find_first_word(s: &str) -> &str {
    let bytes = s.as_bytes();
    for (i, &item) in bytes.iter().enumerate() {
        if item == b' ' {
            return &s[..i];
        }
    }
    &s[..]
}