- From: Bert Bos <bert@w3.org>
- Date: Wed, 25 Jul 2007 11:54:51 +0200
- To: "Cecil Ward" <cecil@cecilward.com>, www-style@w3.org
On Monday 23 July 2007 20:32, Cecil Ward wrote:
> I wish to suggest that the Appendix G Grammar be corrected to avoid
> the difficulties in interpreting whitespace as a combinator within
> selectors.
>
> The production for "combinatory" currently reads:
>
> combinator
>
> : PLUS S*
> :
> | GREATER S*
> | S
>
> ;
>
> I suggest this needs to be amended to read
>
> combinator
>
> : PLUS S*
> :
> | GREATER S*
> | S+
>
> ;
>
> CSS3 seems to agree.
>
> I couldn't possibly say, but for all I know this may possibly have
> influenced the fault seen in issue #4870 in the current CSS validator
> - see http://www.w3.org/Bugs/Public/show_bug.cgi?id=4870 .
Both the Selectors module and appendix G of CSS 2.1 correctly deal with
comments in selectors, but they do it differently. Maybe the grammar in
the Selectors module is indeed easier for programmers...
The question is what tokens occur in these two selectors:
P P
P /*comment*/ P
both have two spaces. The first one clearly results in just three
tokens:
IDENT S IDENT
The question is if the second one results in three tokens or in four:
IDENT S S IDENT
Appendix G shows how to remove comments so that the spaces on either
side of the comment only create a single S token. The grammar in the
Selectors module instead creates two S tokens.
Bert
--
Bert Bos ( W 3 C ) http://www.w3.org/
http://www.w3.org/people/bos W3C/ERCIM
bert@w3.org 2004 Rt des Lucioles / BP 93
+33 (0)4 92 38 76 92 06902 Sophia Antipolis Cedex, France
Received on Wednesday, 25 July 2007 09:55:01 UTC