On Mon, 30 Jul 2007, Alan Barrett wrote:
It sure was. Comments and folding white space were allowed between
any two tokens in RFC 822. And since the syntax for zone was:
("+" / "-") 4DIGIT
a comment was allowed between those two. I don't know how to read
3.1.4 and 3.4.3 in RFC 822 and not come up with that interpretation.
Yes, you are correct.
Hang on... "+" and "-" are not in the list of special characters that
RFC822 section 3.1.4 says are used to delimit tokens. So I would say
that, given input like "+0000", the sign and the digits together make
up an "atom" per the description in section 3.1.4 and the grammar in
section 3.3. The ( ("+" / "-") 4DIGIT ) production in the grammar in
section 5.1 is looking inside a single token, not looking at two tokens.
For another example of grammar productions that look inside a single
lexical token, consider RFC822's definitions of quoted-pair and
quoted-string. I hope nobody argues that the "\" and the CHAR in a
quoted-pair are two tokens and that LWSP is allowed between them.
--apb (Alan Barrett)