Re: why 4.3 Structured Datatypes should wait

In short, this argument might just as well hold for RDF datatypes which also
seem to use URIs for XML Schema simple datatypes.

(this is a real problem though)

why not extend RDF datatypes to enable complex/structured datatypes ala XML
literals e.g.

ex:foo ex:prop ex:structured"<this>is a <simple/> structured
datatype</this>" .

where ex:structured is defined to be something like:

<!ELEMENT this (PCDATA|simple)*>

I could live with typed XML literals for the time being.

I do agree that the current situation with URIs for XML Schema particles is


> In short: because the XML Schema WG hasn't
> yet decided how XML schema components fit
> into URI space.
> cf.
> * TAG interested in progress on URIs for schema components (NUNs)
> Dan Connolly (Thu, Oct 17 2002)
> To elaborate a bit, yes, it would be nice to say...
>  @prefix : <http://example/vocab#>.
>  @prefix xs: <>.
>  :description rdfs:domain :Product;
>    rdfs:range :ProductDescription.
>  :ProductDescription a xs:ElementDeclaration;
>    xs:name "desc";
>    xs:typeDefinition [ a xs:ElementOnly;
>      xs:contentModel [ xs:sequence (:name :photoref :blurb)].
> so that
>   <desc>
>     <name>SuperCam</name>
>     <photo ref="supercam1.jpg"/>
>     <blurb>best camera since sliced bread!</blurb>
>   </desc>
> was an element of the class :ProductDescription.
> In fact, there's a nifty UML diagram in the XML Schema spec,
> and if our UML/OWL stuff works out, it should be a slam-dunk
> to model stuff like schema components and properties,
> and to say that XML Schema documents have the corresponding
> RDF graph semantics.
> But the bad news is: the current XML Schema specs
> don't determine URIs for schema components such
> as :ProductDescription. They get as far as
> a (namespace name, localname, whichsortathing) tuple,
> but they don't tell you the name for the thing.
> I suppose we could write an expression for
> "the element declaration schema component with
> localname 'desc' in the namespace 'http://example/vocab' "
> ala
>   [ a xs:ElementDeclaration;
>      xs:name "desc";
>      xsmap:namespace <http://example/vocab>
>   ]
> but... is that what you really want to do?
> So I'd like to keep 4.3 postponed; perhaps
> our requirements document should show this
> as a goal we didn't meet... or more straightforwardly:
> let the issues list cite this message, and
> let an update of the requirement document cite all the
> postponed issues, as we go to last call.
> --
> Dan Connolly, W3C

Received on Wednesday, 23 October 2002 23:02:50 UTC