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Re: RDF-ISSUE-80 (rdf:PlainLiteral): Ask OWL and RIF WGs to update the rdf:PlainLiteral spec [RDF General]

From: Sandro Hawke <sandro@w3.org>
Date: Thu, 17 Nov 2011 14:14:08 -0500
To: Richard Cyganiak <richard@cyganiak.de>
Cc: Alex Hall <alexhall@revelytix.com>, Ivan Herman <ivan@w3.org>, RDF Working Group WG <public-rdf-wg@w3.org>
Message-ID: <1321557248.15001.17.camel@waldron>
On Thu, 2011-11-17 at 19:09 +0000, Richard Cyganiak wrote:
> On 17 Nov 2011, at 17:10, Alex Hall wrote:
> > 1. Give a name to the class of untyped literals in RDF, for use in domain/range statements and in data models that require a datatype IRI for all literals.
> > 2. Allow values from the RDF data model, which has 3 slots (lexical, language, datatype) to be expressed in OWL and RIF data models which only have 2 slots (lexical, datatype) by mashing together the lexical and language parts of the RDF model.
> > 
> > The first issue might no longer be a concern with the addition of rdf:LanguageString, but the second issue is still relevant.
> 
> +1
> 
> > Short of modifying the OWL and RIF data models to align with RDF, they'll still require something along the lines of rdf:PlainLiteral, even if it's no longer called rdf:PlainLiteral.
> 
> This is no longer necessary for strings without language tag because they now have two slots (lexical form, “xsd:string”).
> 
> It's still necessary for strings with language tag. The obvious way of getting those into two slots is now to define a “compatibility lexical space” and “compatibility L2V mapping” for rdf:langString. The effect would be that "chat"@en has a normal “RDF lexical form” (“chat”) and a “compatibility lexical form” (“chat@en”). The latter is not part of RDF graphs, but it can be used in “compatibility graphs” or whatever you want to call the two-slot representation.

That makes sense.    I wonder if anyone feels motivated to do it....

    - s

> Best,
> Richard
> 
> 
> 
> > That said, I agree that rdf:PlainLiteral will need a rewrite to accurately reflect changes in RDF 1.1
> > 
> > -Alex
> > 
> >  
> > *I* don't have a problem with that. I don't think rdf:PlainLiteral made sense in the first place. But the OWL and RIF people might care that one of their documents no longer has any foundation in the RDF data model.
> > 
> > And I *do* slightly care that they're squatting in the RDF namespace. Why were they allowed to do that? This could be fixed as part of the update of the rdf:PlainLiteral document.
> > 
> > > Let's just
> > > include some "Historical Notes" in RDF 1.1 that explains what terms like
> > > "Plain Literal" meant, and how they should now be understood.
> > 
> > Well, we currently have this:
> > 
> > [[
> > In earlier versions of RDF, literals with a language tag did not have a datatype IRI, and simple literals could appear directly in the abstract syntax. Simple literals and literals with a language tag were collectively known as plain literals.
> > ]]
> > http://dvcs.w3.org/hg/rdf/raw-file/default/rdf-concepts/index.html#dfn-plain-literal
> > 
> > I would rather not clutter the spec too much with “Historical Notes” that no one will care about five years down the road. The spec already had way too many notes in 2004, and the need to point out every change between 2004 and 1.1 doesn't help.
> > 
> > Best,
> > Richard
> > 
> > 
> > 
> > > Then, I
> > > think, existing systems will be fine.     (Or... perhaps I'm missing
> > > something.)
> > >
> > >    -- Sandro
> > >
> > >> Thanks
> > >>
> > >> Ivan
> > >>
> > >> On Nov 10, 2011, at 18:06 , RDF Working Group Issue Tracker wrote:
> > >>
> > >>>
> > >>> RDF-ISSUE-80 (rdf:PlainLiteral): Ask OWL and RIF WGs to update the rdf:PlainLiteral spec [RDF General]
> > >>>
> > >>> http://www.w3.org/2011/rdf-wg/track/issues/80
> > >>>
> > >>> Raised by: Richard Cyganiak
> > >>> On product: RDF General
> > >>>
> > >>> The ISSUE-12 and ISSUE-71 resolutions, which are now implemented in the RDF Concepts ED [1], have removed the distinction between plain and typed literals from the RDF abstract syntax.
> > >>>
> > >>> This has a major effect on the rdf:PlainLiteral spec [2]. Parts of it are now obsolete, and the rest needs updating.
> > >>>
> > >>> RDF-WG should ask OWL-WG and RIF-WG to update the document.
> > >>>
> > >>> [1] http://dvcs.w3.org/hg/rdf/raw-file/default/rdf-concepts/index.html
> > >>> [2] http://www.w3.org/TR/rdf-plain-literal/
> > >>>
> > >>>
> > >>>
> > >>
> > >>
> > >> ----
> > >> Ivan Herman, W3C Semantic Web Activity Lead
> > >> Home: http://www.w3.org/People/Ivan/
> > >> mobile: +31-641044153
> > >> FOAF: http://www.ivan-herman.net/foaf.rdf
> > >>
> > >>
> > >>
> > >>
> > >>
> > >>
> > >>
> > >
> > >
> > >
> > 
> > 
> > 
> 
> 
Received on Thursday, 17 November 2011 19:14:27 GMT

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