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Re: WD-rdf-syntax-grammar-20010906 in RELAX NG

From: James Clark <jjc@jclark.com>
Date: Mon, 17 Sep 2001 18:07:19 +0700
Message-ID: <010601c13f68$eb1783a0$0e00a8c0@bkk.thaiopensource.com>
To: "www-rdf-comments" <www-rdf-comments@w3.org>, "Dave Beckett" <dave.beckett@bristol.ac.uk>
It seems like rdf:li needs to be excluded from matching propAttr, given the

rdf-containers-syntax-vs-schema/error001.rdf

test case.


----- Original Message -----
From: "James Clark" <jjc@jclark.com>
To: "www-rdf-comments" <www-rdf-comments@w3.org>; "Dave Beckett"
<dave.beckett@bristol.ac.uk>
Sent: Monday, September 17, 2001 4:30 PM
Subject: Re: WD-rdf-syntax-grammar-20010906 in RELAX NG


>
> > > With typedNode, propertyElt and propAttr, the WD actually specifies
any
> > > namespace URI is allowed.  I'm guessing that the intention is actually
> to
> > > allow any namespace URI other than the absent namespace URI and the
RDF
> > > namespace URI. ...
> >
> > Not quite.  The intention is that rdf:type as an attribute must be
> > handled using the typeAttr production, and all others use the
> > propAttr.   For any namespace, that does include the RDF namespace;
> > but non-namespaced attributes or elements are not allowed.  I assume
> > the -(local:*...) terms exclude non-namespaced attributes & elements.
>
> So propAttr is supposed to match anything other than
>
> + a non-namespace attribute
> + rdf:type
>
> ? Don't you also need to exclude rdf:ID, rdf:about, rdf:aboutEach?
> Otherwise an element could have both an rdf:ID and, say, an rdf:about
> attribute, even though the syntax has a choice of rdf:ID and rdf:about,
> because one of them would match propAttr.
>
> What exactly is the list of RDF attribute names that propAttr cannot
match?
> Probably rdf:bagID, rdf:parseType, rdf:resource need to be excluded in
> addition to rdf:ID, rdf:about, rdf:aboutEach. rdf:type.
>
> What about propertyElt and typedNode? Can they match element names from
the
> rdf namespace?
>
> > Thanks for catching this - we need to be clearer.
> >
> > > ...  Maybe this is supposed to be handled by the requirement in
> > > the spec that in A|B priority is given to A.  I would strongly suggest
> that
> > > this priority concept is not a good idea.  I think that making this
> rigorous
> > > would be hard and would require getting into procedural details of the
> > > parsing process, which it would be far better to avoid.
> >
> > I felt awkward adding that priority, but I wanted to make it clear
> > that rdf:type matched only one grammar production.  The other
> > alternatives include -
> >
> >   * specifying something like "rdf:type OR any other property that
> >      isn't  rdf:type"
>
> Specifying "anything other than rdf:type" is easy in RELAX NG and has a
> clean, precise semantics.  In the non-XML syntax it would be just
>
> attribute * - rdf:type { ... }
>
> James
>
>
Received on Monday, 17 September 2001 07:07:24 GMT

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