On Wed, Oct 06, 2010 at 01:18:47PM -0400, Stefan Berger wrote:
Daniel Veillard <veillard@redhat.com> wrote on 10/06/2010 12:00:04 PM:
Re: [libvirt] [patch 4/5] nwfilter: Extend schema to accept state attribute
On Fri, Oct 01, 2010 at 08:28:53PM -0400, Stefan Berger wrote:
Extend the nwfilter.rng schema to accept state attributes.
Signed-off-by: Stefan Berger <stefanb@us.ibm.com> [...] + + <define name='stateflags-type'> + <data type="string"> + <param name="pattern">((NEW|ESTABLISHED|RELATED|INVALID)(, (NEW|ESTABLISHED|RELATED|INVALID))*|NONE)</param> + </data> + </define> </grammar>
Hum, we really want to accept something like NEW,NEW,NEW,NEW ? I understand that we may want to add RELATED to another state, but that regexp could probably be refined, isn't it ?
The only solution that I could come up with is to explicitly enumerate all possible combinations of the above 4 words (15 combinations). This solution would then also force the user to provide them in a particular order:
(A)|(B)|(C)|(D)|(A,B)|(A,C)|(A,D)|(B,C)|(B,D)|(C,D)|(A,B,C)|(A,B,D)|(A,C,D)|(B,C,D)|(A,B,C,D)
When not forcing the user into a sequence we'd need something like this here:
(A)|(B)|(C)|(D)|(A,B)|(A,C)|(A,D)|(B,C)|(B,D)|(C,D)|(A,B,C)|(A,B,D)|(A,C,D)|(B,C,D)|(A,B,C,D)|
(B,A)|(C,A),(D,A),(C,B),(D,B),(D,C),(A,C,B)|(A,D,B)|(A,D,C)|(B,D,C)|(A,B,D,C)| ...
I think the proposed solution is not as 'strict' as it should be but compared to the other two solutions I think it is 'ok' -- unless there is a fundamentally different way of writing this type of regex.
yeah, that's not possible as far as I know, I was somehow hoping that not all sets made sense ((NEW|ESTABLISHED|RELATED|INVALID)(,(NEW|ESTABLISHED|RELATED|INVALID)){0,3}|NONE) would at bound the regexp, but that's in no way simpler... Let's kee the current version unless someone gets a brilliant idea in the meantime :-) Daniel -- Daniel Veillard | libxml Gnome XML XSLT toolkit http://xmlsoft.org/ daniel@veillard.com | Rpmfind RPM search engine http://rpmfind.net/ http://veillard.com/ | virtualization library http://libvirt.org/