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Re: New syntax spec

From: Dave Beckett <dave.beckett@bristol.ac.uk>
Date: Thu, 13 Sep 2001 14:01:22 +0100
To: www-rdf-comments <www-rdf-comments@w3.org>
CC: Rick Jelliffe <ricko@allette.com.au>
Message-ID: <976.1000386082@tatooine.ilrt.bris.ac.uk>
>>>Rick Jelliffe said:
> 
> But surely that is wrong, because
>    [attributes]=set(idAboutAttr?, bagIdAttr?, propertyAttr*)
> then expands to
>    [attributes]=set(idAboutAttr?, bagIdAttr?, (typeAttr | propAttr)*)
> which, allowing multiple typeAttr, is impossible?
> 
> An XML element can only have one attribute with a single name***
> 
> Do you mean this:
>    [attributes]=set(idAboutAttr?, bagIdAttr?, typeAttr?, propAttr* )

True (and this is a bit better) but since propAttr also matches
"rdf:type", how do I express that when rdf:type is seen, typeAttr
should be accepted in priority to propAttr.

Maybe I could define propAttr as all namespaced attributes except for
those with namespace 'rdf-ns' and local name 'type'.  Which is rather
a mess. 


> Also, I think by "any" namespace you always mean "any except RDF".
> And does this syntax exhaust the RDF namespace? 

No I don't mean except RDF.  You can put RDF-namespaced properties
anywhere that properties can be used - attributes or elements.


<snip/>

> *** Actually, one could think of getting around this using
>   <x  xmlns:r1="namespace for rdf" xmlns:r2="namespace for rdf"
>         r1:type=" ..." r2:type="..." />
> but Namespace in XML explicitly disallows this in 5.3
> "Uniqueness of Attributes"
> http://www.w3.org/TR/REC-xml-names/

Yes, there would be different solutions if the standards upon which
we are based were not the way they are.  C'est la vie.

Dave
Received on Thursday, 13 September 2001 09:01:23 GMT

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