rash.old/src/parser.rs

fn parse_after_whitespace(char_splitted_command_line: &mut Vec<char>, argv: &mut Vec<String>) -> Vec<String> {
    let current_char_option = char_splitted_command_line.pop();

    if current_char_option.is_none() {
        argv.to_vec()
    } else {
        let current_char = current_char_option.unwrap();

        if current_char.is_whitespace() {
            parse_after_whitespace(char_splitted_command_line, argv)
        } else {
            parse_initial_state(char_splitted_command_line, &mut String::from(current_char.to_string()), argv)
        }
    }
}

fn parse_initial_state(char_splitted_command_line: &mut Vec<char>, current_arg: &mut String, argv: &mut Vec<String>) -> Vec<String> {
    let current_char_option = char_splitted_command_line.pop();

    if current_char_option.is_none() {
        argv.push(current_arg.to_string());
        argv.to_vec()
    } else {
        let current_char = current_char_option.unwrap();
        if current_char.is_whitespace() {
            argv.push(current_arg.to_string());
            parse_after_whitespace(char_splitted_command_line, argv)
        } else {
            current_arg.push(current_char);
            parse_initial_state(char_splitted_command_line, current_arg, argv)
        }
    }
}

fn split_string_in_chars(string_to_split: &String) -> Vec<char> {
    string_to_split.chars().rev().collect()
}

pub fn parse(command_line: &String) -> Vec<String> {
    let mut argv: Vec<String> = Vec::new();
    let mut char_splitted_command_line: Vec<char> = split_string_in_chars(&command_line);
    let mut new_arg = String::new();

    argv = parse_initial_state(&mut char_splitted_command_line, &mut new_arg, &mut argv);

    argv
}