[sc34wg3] CXTM draft for review

Lars Marius Garshol larsga at garshol.priv.no
Mon Apr 14 06:52:44 EDT 2008


* Jirka Kosek
>
> I have just noticed that CXTM and TMDM (and probably other related  
> spec) use
>
> http://www.w3.org/2001/XMLSchema
>
> as namespace for XML Schema Datatypes. While W3C XML Schema spec  
> recommends to use the following namespace if only datatypes from XML  
> schema are reused:
>
> http://www.w3.org/2001/XMLSchema-datatypes

I half-heard this in Oslo, and started wondering what it really meant.  
Does this mean that there are *two* namespaces for XML Schema data  
types, so that there are in fact *two* URIs for each data type?

That sounds *very* odd, because it effectively means that from the  
point of view of both RDF and Topic Maps there are two versions of  
every data type...

Can this really be true?

I see that section 3.1 of XSD-2 really does say this:
http://www.w3.org/TR/xmlschema-2/#namespaces

I note that the RDF spec uses "xsd:" as a prefix for its datatypes  
without actually defining what the expansion of "xsd:" is:
http://www.w3.org/TR/rdf-concepts/

The RDF/XML spec, however, uses the "normal" XSD namespace in its  
example:
http://www.w3.org/TR/2004/REC-rdf-syntax-grammar-20040210/#section-Syntax-datatyped-literals

The RDF/XML test cases do the same:
http://www.w3.org/TR/2004/REC-rdf-testcases-20040210/

So it seems to me that the W3C is ignoring this part of the XSD spec,  
and that perhaps we should, too. Otherwise we'll have translate  
datatype URIs between the two namespaces when converting RDF<->TM,  
which seems a bit ... odd.

--Lars M.


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