- From: Steve Harris <steve.harris@garlik.com>
- Date: Sat, 3 Apr 2010 08:45:10 +0100
- To: Andy Seaborne <andy.seaborne@talis.com>
- Cc: SPARQL Working Group <public-rdf-dawg@w3.org>
On 2010-04-02, at 22:05, Andy Seaborne wrote:
> The FILTER could be artificially forced using a extra {}
>
> { { ?s rdf:type :T
> FILTER NOT EXISTS { ?s :p ?v . }
> }
> ?s :q ?v
> }
>
> This is unnecessary - the more direct syntax is closer to the OPTIONAL/!BOUND idiom that I think it the important thing to make easier.
!BOUND can only be used inside a FILTER as well (though OPTIONAL is not mobile) and users must be used to this, so I'm not sure this is a significant problem.
The main reason I thought the compromise that was found at F2F3 was good was that it made it clear that NOT EXISTS was executed per solution, like a FILTER, and not as an algebraic operator.
- Steve
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Received on Saturday, 3 April 2010 07:45:40 UTC