Re: [xml] Schema validity failure for valid document

[Kasimier Buchcik <kbuchcik 4commerce de>]

Hi,

Daniel Veillard wrote:
> On Tue, Jan 11, 2005 at 12:14:19PM +0100, Kasimier Buchcik wrote:
>
> > Hi,
> >
> > Daniel Veillard wrote:
> >
> > > > What about the following:
> > > > 1. xmlRegExecErrInfo would return an array of automaton transition
> > > > indices (well, if the transitions are accessible through an index).
> > > > 2. We could then iterate through all the given transitions and extract
> > > > the info using accessor functions like:
> > > > const xmlChar * xmlRegExecGetValue(int transitionId)
> > > > void * xmlRegExecGetData(int transitionId)
> > >
> > >
> > > Too complex. Depending on the compilation you may address transitions 
> > > with integers or with pointers. I don't think exposing that deep a level
> >
> > I don't agree that it's too complex and exposing. If the atoms holding
> > the information would be always accessible through integer indices in
> > xmlregexp.c (and I think any struct can be put in an array and be given
> > an index), accessor functions would be the most encapsulating and
> > extensible access to those informations I can think of. Plus, access of
> > information items through integer indices is a highly abstract thingy.
> > So not exposing at all IMHO.
>
>
>   I think it exposes too much of the implementation that it would prevent
> different implementation stategies. For example if I wanted to integrate
> RNG derivation based kind of validation stategies, then you don't have
> transitions in a given state but an expression of the remaining formal
> automata accepted at that point. This is crossing the interface exposing
> the implementation stategy, and I prefer to avoid this. Extracting potential
> accepted tokens does not expose the implementation stategy.

OK. Maby it's just the fact that I don't have the complete overview of
what it is intended for.

> > > is safe. Maybe we can give informations when building the automata,
> > > associating an error string to a transition (or a state) and providing
> > > back that optional error string from xmlRegExecErrInfo if reached. That
> >
> > We are already associating the schema type to the transition. But
> > having an extra field as a marker per transition would be good.
>
>
>   Do you want an integer or a char pointer ?

Hmm, an integer. I hate such decisions ;-) Do it your way.

> > > sounds way simpler to implement and use. When building those "dead" 
> > > transition
> > > you know what they represent and what to report if transiting though them.
> >
> > In this case yes, the negated namespace wildcard is the only one with a
> > dead-end; so it's distinguishable.
>
>
>   Okay, but dead-end state are unlikely to be generated by normal regexp
> process but since we expose automata APIs I prefer a more generic apparoach.
> It also sounds the right solution from a formal point of view, it should
> still work if we change the automata generated for whatever reason.

Regards,

Kasimier