W3C home > Mailing lists > Public > public-rdf-wg@w3.org > October 2011

Re: why I don't like named graph IRIs in the DATASET proposal

From: Pat Hayes <phayes@ihmc.us>
Date: Fri, 7 Oct 2011 21:46:48 -0500
Cc: Richard Cyganiak <richard@cyganiak.de>, Pierre-Antoine Champin <pierre-antoine.champin@liris.cnrs.fr>, "public-rdf-wg@w3.org" <public-rdf-wg@w3.org>
Message-Id: <D91BBA5C-D753-4CEE-8EB9-BE8A1F8F24D6@ihmc.us>
To: Ian Davis <ian.davis@talis.com>

On Oct 7, 2011, at 5:06 AM, Ian Davis wrote:

> On Wed, Oct 5, 2011 at 9:14 PM, Pat Hayes <phayes@ihmc.us> wrote:
> 
> But every time you use the name to refer to the graph, you are making an inference. And the way we have set things up with graph labels (see above) it is an *invalid* inference. So forget having RDF 'metadata' using graph labels/names: that is literally impossible, with the current conventions about the fourth IRI in a quad store. There is NO WAY to refer to a graph in RDF, with the current semantics. If we want to do this, we have to change the semantics rules so that the graph label denotes the graph it labels. This is trivial to do, of course, and to me it seems like a no-brainer, but apparently the WG does not agree. Which is fine, but then we all have to live with the consequences.
> 
> 
> Can I not refer to a graph indirectly with a blank node?
> 
> [ rdf:type rdf:Graph ; rdf:graphName "http://example.com/mygraph" ]

Sure, you could do this if you had any confidence that rdf:Graph had some semantic relationship to actual RDF graphs. That however would take a (pretty hefty) semantic extension to the current semantics. And, even if we had this extension, this RDF would, AFAIKS, simply make the bnode denote *some* graph, but would not specify what the graph was. That isn't what I mean by 'naming' a graph. 

Pat

> 
> 
> 
> -- 
> Ian Davis, Chief Technology Officer, Talis Group Ltd.
> http://www.talis.com/ | Registered in England and Wales as 5382297

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Received on Saturday, 8 October 2011 02:47:22 GMT

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