macro_rules! chain_append {
        ($a:expr, $($b:literal .. $c:literal),* $($d:literal),*) => {{
            $a$(.chain($b..$c))*$(.chain(once($d)))*
        }}
    }

error: local ambiguity: multiple parsing options: built-in NTs literal ('b') or literal ('d').
  --> rasp_event/src/url_encoding.rs:46:35
   |
46 |         chain_append!(b'A'..b'Z', b'a'..b'z', b'0'..b'9', b'-', b'_', b',', b'~');
   |                                   ^^^^