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Re: RDF should allow XML datatypes

From: Jonathan Borden <jonathan@openhealth.org>
Date: Tue, 29 Oct 2002 22:06:47 -0500
Message-ID: <007701c27fc1$62ab89e0$7c674544@ne.mediaone.net>
To: "Dave Beckett" <dave.beckett@bristol.ac.uk>
Cc: "www-rdf-comments" <www-rdf-comments@w3.org>, <danbri@w3.org>

Dave Beckett wrote:

>
> Not sure who this is addressed to, but it mostly deals with syntax,
> so I'll reply.  The RDF concepts and abstract syntax editors may also
> have some comments I expect.
>
>
> >>>Jonathan Borden said:
> >
> > RDF datatyping should allow the form:
>
> This is asking for a feature by showing you think it should be
> implemented, which isn't a good way to approach it.
>
> You are obliquely refering to the requirements of WebOnt I assume,
> and in particular, 4.3 as recorded in:
>
http://www.w3.org/2001/sw/WebOnt/webont-issues.html#I4.3-Structured-Datatype
s
>
> which I note, says: "Status Postponed"

The issue was originally prompted by Dan Brickley
http://lists.w3.org/Archives/Public/public-webont-comments/2002Apr/0004.html
and the OWL requirements document.

The issue which is "Postponed" dealt with a "deep" understanding of XML
Schema by OWL, essentially an OWL representation of an XML Schema particle.
A robust solution to this issue would require a fair amount of work, and
indeed would depend on URIrefs for XML Schema particles -- still in
development. Hence postponing the ultimate solution is appropriate.

What I have asked for is far far simpler and perhaps an acceptable interim
solution to OWL's requirements.

>
>
> > http://example.org#foo http://example.org#prop "<this>is some structured
XML</this>"^^http://example.org/SomeSchema#myType
> >
> > where http://example.org/SomeSchema#myType identifies the XML datatype:
> > element this{text}
> >
> > Similarly RDF/XML should provide for:
> >
> > <rdf:Description rdf:about="http://example.org#foo">
> >     <ex:prop rdf:datatype="http://example.org/SomeSchema#myType">
> >             <this>is some structured XML</this>
> >     </ex:prop>
> > </rdf:Description>
> >
> >
> > 1. There is no compelling reason to prohibit this given the current RDF
> > datatyping solution for which this is a minor modification to the
syntax.
>
> As editor of the RDF/XML spec, I feel this is not a minor syntax
> change and in particular does not match our abstract syntax for
> datatyped literals, so would require a change to RDF.

since RDF datatyping doesn't seem to be finalized, I don't seem the great
resistance to relatively small changes.
>
>
> > 2. Allowing this will be very useful for OWL which needs to deal with
> > structured datatypes
>
> "Postponed"?  Plus you can still do it with the rdf:datatype, since
> it allows any lexical form to be given as a string, that includes XML
> infosets serialised to a string.

This is essentially what I am suggesting but to be clear:

"&lt;foo&gt; content &lt;/foo&gt;" is _not_ XML serialized, rather a string.
A serialization of an XML infoset is plainly XML i.e.

<foo> content </foo>

So what is the problem with:

http://example.org#foo http://example.org#bar "<foo> content
</foo>"^^http://example.org#baz

I don't see the problem.

Jonathan
Received on Tuesday, 29 October 2002 22:26:07 GMT

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