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Re: TR: Re: Constraining Containers - erratum

From: Pierre-Antoine Champin <champin@bat710.univ-lyon1.fr>
Date: Tue, 25 Apr 2000 11:25:05 +0200
Message-ID: <39056471.3050808@bat710.univ-lyon1.fr>
To: Jonas Liljegren <jonas@paranormal.se>, RDF Intrest Group <www-rdf-interest@w3.org>
Jonas Liljegren <jonas@paranormal.se>
> > Actually, I just saw I misunderstood you :
> > you were suggesting
> > 
> > <rdf:Property ID="myprop">
> >     <rdfs:range rdf:resource="&rdf;Seq"/>
> >     <rdfs:containerRange rdf:resource="&rdf;Literal"/>
> > </rdf:Property>
> > 
> > and I suggested
> > 
> > <rdf:Property ID="myprop">
> >     <rdfs:range rdf:resource="&rdf;Literal"/>
> >     <rdfs:containerRange rdf:resource="&rdf;Seq"/>
> > </rdf:Property>
> > 
> > The reason I prefer the second option is that rdfs:range
> > keeps addressing the atomic value(s) of the property, (for
> > either mono- or multi-valued properties)
> > and containerRange addresses the kind of multi-valuation
> > allowed.
> 
> Containers are not only used because a subject has many objects with a
> specific property.
> 
> How would you express the case there you always want the range to be a
> container, even if that container has one or no members?



Then I would write

<rdf:Property ID="myprop">
     <rdfs:range rdf:resource="&rdf;Seq"/>
</rdf:Property>

but then I loose the information about the seq's elements type.

> My suggestion is backwards comaptible. A parser that doesn't support
> containerRange would still validate the model because the semantics of
> rdfs:range remains.


that's right ;
mine is not backward compatible because it allows 2 effective ranges
(atomic type OR container type) though RDFS can't allow that (range is 
unique).





>  I can't think of a good reason to allow both for a specific property.

simplicity. As an RDF user, I would rather type


<dc:Author> Pierre-Antoine </dc:Author>

than

<dc:Author> <rdf:Seq> <rdf:li> Pierre-Antoine </rdf:li> </rdf:Seq> 
</dc:Author>

just because someone pointed out
that there MAY be more than one author !

   Pierre-Antoine
Received on Tuesday, 25 April 2000 05:23:03 GMT

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