Rust 1.42 will provide some pattern matching improvements and will be released on Mar 12, for details see https://blog.rust-lang.org/inside-rust/2020/03/04/recent-future-pattern-matching-improvements.html

I think it's a good opportunity to replace the current Vec<&str> apis to [&str; 4] and pattern matching whether the passing argument is of length 3 or 4