RE: Ticket 162, was: Ambiguity in ABNF for comment

Julian Reschke wrote:
> So how about:
> 
>       quoted-string  = DQUOTE *( qdtext / quoted-pair ) DQUOTE
>       qdtext         = OWS / %x21 / %x23-5B / %x5D-7E / obs-text
>                      ; OWS / VCHAR except DQUOTE / obs-text

It should be 'VCHAR except DQUOTE and "\"'.

>       comment        = "(" *( ctext / quoted-pair / comment ) ")"
>       ctext          = OWS / %x21-27 / %x2A-5B / %x5D-7E / obs-text
>                      ; OWS / VCHAR except "(", ")" and "\" / obs-text

It should be 'VCHAR except "(", ")", and "\"' (one more comma), based on the
style used in the rest of the document.

> Furthermore, am I missing something, or can't we also remove "comment"
> from the right hand side of the "comment" production?

IMO, nested comments are a bad idea because it makes comment (and thus Via
and User-Agent) non-regular. They should be treated as obsolete (like
obs-text), especially since those headers are very frequently parsed with
regular expressions.

- Brian