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Re: SWC out of sync on rdf:PlainLiteral

From: Sandro Hawke <sandro@w3.org>
Date: Thu, 04 Mar 2010 08:11:47 -0500
To: Jos de Bruijn <jos.debruijn@gmail.com>
cc: RIF <public-rif-wg@w3.org>
Message-ID: <25149.1267708307@waldron>

> SWC doesn't map plain literals to anything. According to the RDF
> semantics, plain literals without language tags are always mapped to
> themselves, i.e., strings of unicode characters. Now, XSD specifies that
> xs:string literals are also mapped to themselves, and thus they
> correspond 1-to-1 to plain literals w/o language tags.
> Now, it happens to and be the case that the value space of
> rdf:PlainLiteral also includes all strings. Therefore, there is a
> one-to-one correspondence between RDF plain literals and xs:strings of
> the form "xyz", on the one hand, and rdf:PlainLiterals of the form
> "xyz@", on the other.

I'm not talking about the value spaces or the semantics, just the
syntactic correspondence in Table 1.  (In terms of the semantics, yes, I
agree with everything you say above.)

    -- Sandro

> 
> Best, Jos
> 
> On 2010-03-02 20:06, Sandro Hawke wrote:
> > During the telecon today we looked at
> > 
> >    http://www.w3.org/2005/rules/wiki/RDF_Combination_Constant_Equivalence_2
> > 
> > and it seems that while that example is supported by the SWC, SWC isn't
> > saying quite the right thing, here.  It says plain literals without
> > language tags map to xs:string constants, but I think it would be better
> > to map to rdf:PlainLiteral constants.  The difference is actually
> > invisible to any entailment test (I think?  maybe it depends on the
> > entailment regime?), so in a sense RIF doesn't care, but for interchange
> > purposes is does matter.  In particular, SPARQL, when not doing
> > entailment, will notice the difference.   
> > 
> > Do you remember why it's xs:string now?
> > 
> > This isn't a huge problem, but if there's no compelling reason not to
> > change it, I think it's more correct to map to rdf:PlainLiterals.
> > 
> >      -- Sandro
> 
> -- 
> Jos de Bruijn
>   Web:          http://www.debruijn.net/
>   LinkedIn:     http://it.linkedin.com/in/josdebruijn
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>   Google Talk:  jos.debruijn@gmail.com
>   Mobile phone: +43 660 313 5733
Received on Thursday, 4 March 2010 13:11:52 GMT

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