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RE: [Fwd: xmlns, uri+name pairs or just uris..? Clarification n eeded.]

From: Graham Klyne <GK@Dial.pipex.com>
Date: Mon, 31 Jul 2000 21:27:57 +0100
Message-Id: <4.3.2.7.2.20000731210652.00aab5c0@pop.dial.pipex.com>
To: "McBride, Brian" <bwm@hplb.hpl.hp.com>
Cc: RDF-list <www-rdf-interest@w3.org>
Brian,

At 08:33 PM 7/31/00 +0100, McBride, Brian wrote:
>Hi Graham,
>
> > It seems to me that the requirement to find the
> > namespace-related
> > portion of a URI in isolation is not reasonable.  It's also
> > not clear to me
> > what purpose it serves.
>
>SiRPAC's java API only ever passes through the full URI - it
>never passes through the URI split into the namespace part
>and the rest.  If an RDF processor wishes to determine what
>schema applies, perhaps to do validation or schema directed
>editing, it needs to be able to figure out the right namespace.

OK, that is an answer to my second question.  I do wonder if it's a real 
requirement.

It seems reasonable to me that an application doing schema directed 
processing might have some kind of a priori knowledge of the schemas being 
used (by embedded labels, implied by the application, or other means), from 
which the URIs defined by each such schema can be deduced.

(There's still a potential messy problem of two schemas that define the 
same URI.)

>So either the java api needs to change or there needs to be
>a way to figure out the namespace.  I guess I'm uncomfortable
>with Dan's suggestion of the parser adding statements to the
>model - not its job to modify the model it is given really.

OK, it's not the parser's job to *modify* the model.  But, for example, 
additional labels might be defined to be part of the model defined by some 
given syntax.  Much as having ID on a statement property is sometimes taken 
to define inclusion of reification of that statement in the resulting model.

>Further, independent of the API, there are situations when it would be
>helpful for an RDF processor to be able to determine the
>namespace of a resource from its URI, e.g. when it encounters
>a subPropertyOf property in a schema.  The processor may well
>wish to determine the schema of the super property, e.g. to
>determine domain and range constraints.

Indeed.  But "in isolation" was part of my comment.  See above.

#g

------------
Graham Klyne
(GK@ACM.ORG)
Received on Monday, 31 July 2000 16:47:52 GMT

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