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Fwd: Re: Disjointness of value spaces

From: Brian McBride <bwm@hplb.hpl.hp.com>
Date: Thu, 31 Oct 2002 17:35:41 +0000
Message-Id: <5.1.0.14.0.20021031173529.09a39600@0-mail-1.hpl.hp.com>
To: RDF Core <w3c-rdfcore-wg@w3.org>


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>To: Brian McBride <bwm@hplb.hpl.hp.com>
>Cc: www-xml-schema-comments@w3.org,
>         Patrick Stickler <patrick.stickler@nokia.com>,
>         Graham Klyne <GK@NineByNine.org>
>Subject: Re: Disjointness of value spaces
>From: ht@cogsci.ed.ac.uk (Henry S. Thompson)
>Date: 31 Oct 2002 16:59:44 +0000
>Lines: 52
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>Brian McBride <bwm@hplb.hpl.hp.com> writes:
>
> > The RDFCore WG are putting the finishing touches to a proposal for
> > using XML Schema Datatypes in RDF graphs.  We hope to have a WD to
> > share with folks soon.
>
>Great.
>
> > In doing this, the following question has arisen concerning the value
> > spaces of the primitive datatypes.
> >
> >
> > Are the value spaces of the primitive datatypes disjoint, i.e. are
> > there any cases where a value may be in more than value space.
>
>Not in the XML Schema REC as published.
>
> > A specific case to consider is:
> >
> >    is http://example.org/ in both xsd:string and xsd:anyURI
> >
>
>Disjoint.
>
> > noting that RFC 2396 states:
> >
> >    [[An identifier is an object that can act as a reference to
> >           something that has identity.  In the case of URI, the object is
> >           a sequence of characters with a restricted syntax.]]
> >
> > Put another way, can we assume that if we have two values, one from
> > the value space of one primitive datatype, and the other from the
> > value space of a different primitive datatype, then they must be
> > different values.
>
>Yes.
>
> > To the best of my knowledge, the RDFCore WG has no preferred answer to
> > this question.  We wish to know the answer to ensure that our
> > specification accurately reflects XML Schema datatypes.
>
>We are in fact preparing an erratum to clarify this, as the current
>wording is somewhat unclear, and in one respect wrong.
>
>ht
>--
>   Henry S. Thompson, HCRC Language Technology Group, University of Edinburgh
>           W3C Fellow 1999--2002, part-time member of W3C Team
>      2 Buccleuch Place, Edinburgh EH8 9LW, SCOTLAND -- (44) 131 650-4440
>             Fax: (44) 131 650-4587, e-mail: ht@cogsci.ed.ac.uk
>                      URL: http://www.ltg.ed.ac.uk/~ht/
>  [mail really from me _always_ has this .sig -- mail without it is forged 
> spam]
Received on Thursday, 31 October 2002 12:33:05 EST

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