Re: RDF Schema and XML Schema Part 2: Datatypes

[Eric van der Vlist <vdv@dyomedea.com>]

Jonathan Borden wrote:
> 
> Eric van der Vlist wrote:
> 
> >
> > The latest version of DAML+OIL [1] is proposing some answers to these
> > questions.
> >
> > Some assumptions made here may be considered controversial but the whole
> > construct seems coherent.
> >
> 
> The only problem is that this version of DAML+OIL uses the wrong namespace
> for XML Schema, the RDFism: http://www.w3.org/2000/10/XMLSchema# -- while
> this 'works' for RDF the trailing '#' means that it is a completely
> different namespace ... that is, namespace names cannot be sort of equal, or
> almost equal, they either are or are not equal.

Ooops, I should have thought it was too simple to be true...

> Another problem relates to the assignment of URIs for XSD types which are
> specified as QNames. This issue has been gone over in detail and while I
> have discussed some small changes that IMHO ought be made to the RDF XML
> syntax, the RDF and XML Schema typing mechanisms are unfortunately
> incompatible as they currently stand.

Yes, I have taken part in that discussion too. 

> It is not currently possible in general to identify an XML Schema datatype
> with a URI -- and even if it were such URIs would not be compatible with the
> RDF typedNode XML syntax.

While I don't think it's convenient for the general case, if
http://www.w3.org/2000/10/XMLSchema is the W3C XML Schema for schema (ie
a XML document), http://www.w3.org/2000/10/XMLSchema#string is a
XPointer that identifies the element which ID is "string" and this
happen to be the definition of the string datatype.

In the specific case of the predefined datatypes, I don't think we can
deny that they can be identified as URIs.
 
Eric (ashamed he had missed the trailing "#")
-- 
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Eric van der Vlist       Dyomedea                    http://dyomedea.com
http://xmlfr.org         http://4xt.org           http://examplotron.org
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