//this works
let clean_input = remove_non_chars(input);
    for word in clean_input.split_whitespace() {
        *word_count.entry(word).or_insert(0) += 1;
    }
//this doesn't
    for word in remove_non_chars(input).split_whitespace() {
        *word_count.entry(word).or_insert(0) += 1;
    }