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Re: Definition: Group in query editor's draft

From: Axel Polleres <axel.polleres@deri.org>
Date: Thu, 23 Sep 2010 09:46:21 +0200
Cc: "SPARQL Working Group" <public-rdf-dawg@w3.org>
Message-Id: <E125F03D-E68C-46DD-8A2D-E127C5F45C54@deri.org>
To: "Andy Seaborne" <andy.seaborne@epimorphics.com>
Thanks for clarification, an explaining remark in the doc might help.

Axel

On 23 Sep 2010, at 09:36, Andy Seaborne wrote:

> 
> 
> On 22/09/10 06:59, Axel Polleres wrote:
> > I have a small question about the Definition of "Group" in the query draft:
> >
> > "Group((),&Omega;) = { 1 ->  &Omega; }"
> >
> > ... shouldn't that be:
> >
> > "Group((),&Omega;) = { () ->  &Omega; }"
> >
> > i.e., what is the 1 supposed to mean?
> 
> The 1 is any key.  When the set of groups keys is the empty, which
> happnes for
> 
> SELECT (count(*) AS ?c) { ?s ?p ?o }
> 
> then there needs to be a key value for the group.
> 
> It could be said to be slightly more sense to be (1), not 1, as it's a
> list when then the key isn't empty.  The key just needs to be unique,
> and here, there is only one key so it's arbitrary.
> 
>         Andy
> 
> >
> > Thanks for clarification,
> > Axel
> >
> >
> >
> >
> 
Received on Thursday, 23 September 2010 07:47:06 GMT

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