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Re: SWC out of sync on rdf:PlainLiteral

From: Sandro Hawke <sandro@w3.org>
Date: Thu, 04 Mar 2010 12:30:07 -0500
To: Jos de Bruijn <jos.debruijn@gmail.com>
cc: RIF <public-rif-wg@w3.org>
Message-ID: <8855.1267723807@waldron>
> So, do you propose to change (in Table 1):
> 
> Constant in the xs:string symbol space 	"literal string"^^xs:string
> 
> to:
> 
> Constant in the rdf:PlainLiteral symbol space 	"literal
> string@"^^rdf:PlainLiteral
> 
> ?

Exactly.   Also, a few lines down, there's a bullet:

   * Strings, i.e., constants of the form "my string"^^xs:string may be
     written as "my string".

which would be changed to:

   * Plain literals without language tags, i.e., constants of the form
     "my string@"^^rdf:PlainLiteral may be written as "my string".

Which makes me wonder what other specs, if any, that affects, and what
Hassan & Stella's code does.  Basically, that affects the mapping from
Presentation Syntax to XML Syntax.

> That would be fine for me.

Good...

     -- Sandro

> Cheers, Jos
> 
> On 2010-03-04 14:11, Sandro Hawke wrote:
> >> 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
> >>   Skype:        josdebruijn
> >>   Google Talk:  jos.debruijn@gmail.com
> >>   Mobile phone: +43 660 313 5733
> 
> -- 
> Jos de Bruijn
>   Web:          http://www.debruijn.net/
>   LinkedIn:     http://it.linkedin.com/in/josdebruijn
>   Skype:        josdebruijn
>   Google Talk:  jos.debruijn@gmail.com
>   Mobile phone: +43 660 313 5733
Received on Thursday, 4 March 2010 17:30:14 GMT

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