pub fn field_name(bytes: &[u8]) -> Option<&str>Expand description
The name of one field line, if it is one this server will accept.
Lowercase tchar and at least one of them: token restricted by RFC 9114
§4.2’s rule that a field name arriving with an uppercase character makes the
message malformed. Written as that restriction rather than as its own loop,
so the two cannot come to disagree about what a tchar is. Shared with the
suite’s client, which holds the server to the same rule in the other
direction.