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Re: Comments on RDF Spaces document

From: Pat Hayes <phayes@ihmc.us>
Date: Tue, 29 May 2012 20:42:49 -0500
Cc: public-rdf-wg@w3.org
Message-Id: <96D405D8-E682-4C49-96CB-F9961921177D@ihmc.us>
To: Andy Seaborne <andy.seaborne@epimorphics.com>

On May 28, 2012, at 8:01 AM, Andy Seaborne wrote:

> On 28/05/12 13:11, Ivan Herman wrote:
>>> I don't see why. The only spec that has any reason to mention quads
>>> is N-Quads. (Well, JSON-LD may too but it uses a definition that's
>>> different from Sandro's.) Other uses of quads are implementation
>>> strategies and those don't belong into the specs.
>> Correct. My question was whether this WG would define NQuads as well
>> or not. If we do define NQuads (and I do not believe this has been
>> decided pro or con) then we have to properly define Quads and that in
>> relations to any formalism we have on named graphs. If we decide that
>> NQuads are not to be formally defined by this WG, then indeed this
>> section may become unnecessary.
>> Ivan
> Firstly, I think we really ought to define N-Quads; it's in use and extending the N-Triples work to N-Quads is valuable.
> Secondly, it does not mean we have to give quads as first class items in the extended data model.
> N-Quads-the-format can be defined by:
> <s> <p> <o> <g> .
> is just a way of saying triple <s> <p> <o> in space <g>.  

Do we have to say that last part? Why not just define quads and leave it at that? (What is a "space" exactly? Do spaces have a semantics? Is my space the same kind of space as your space? Etc..) 


> That fits nicely into the way Turtle use state variables to explain parsing.
> We do not strictly need to define a quad and then define how it is associated with a graph pair - just do it in one step.
> It's a matter of simplicity - if quads are defined as a first class concept, we have to keep the dataset-based part of the specs in step with the quads-based parts (e.g. the empty graph case) .  c.f. MT and the rules.
> SPARQL Query does not mention quads.
> SPARQL syntax does for update (it's a rule name in the grammar)
> SPARQL Update uses this as explanation for templates in the form
> { ... GRAPH .... } and constructs a dataset out of them.
> The definition of Graph Store doesn't mention quads.
> 	Andy

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Received on Wednesday, 30 May 2012 01:43:23 UTC

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