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Re: BIND tests

From: Andy Seaborne <andy.seaborne@epimorphics.com>
Date: Mon, 24 Jan 2011 09:33:21 +0000
Message-ID: <4D3D4761.4040008@epimorphics.com>
To: Lee Feigenbaum <lee@thefigtrees.net>
CC: SPARQL Working Group <public-rdf-dawg@w3.org>


On 24/01/11 03:22, Lee Feigenbaum wrote:
> Hi everyone,
>
> This mail discharged my ACTION-371
> (http://www.w3.org/2009/sparql/track/actions/371), to look at the bind
> tests.
>
> I looked over the 7 tests in
> http://www.w3.org/2009/sparql/docs/tests/data-sparql11/bind/ and
> believed them to be accurate and reasonable coverage of the BIND keyword.
>
> I added one new test, bind08, which I believe tests correctly the fact
> that BIND occurs _after_ a group is ended, and hence a FILTER appearing
> before BIND cannot act on the BINDed variables. This is the test:
>
> == query ==
>
> PREFIX : <http://example.org/>
>
> SELECT ?s ?p ?o ?z
> {
> ?s ?p ?o .
> FILTER(?z = 3 )
> BIND(?o+1 AS ?z)
> }
>
> == results ==
>
> (no solutions)
>
> Can someone please check the truth of this test? I don't have a BIND
> implementation to test this with at the moment. Also, if you feel that
> this should not be the semantics of BIND as the WG agreed on a couple of
> months ago, please let us know.
>
> Once this test has been looked at, I'd like to propose that we approve
> these 8 bind tests either this Tuesday or (more likely) one week from
> Tuesday.
>
> Lee

Unfortunately, we missed that the WG agreement is at odds with SPARQL 
1.0 [1]

In SPARQL 1.0, a filter applies to the whole group, where "group" means 
syntax units between the {}.

	Andy

[1] http://www.w3.org/TR/rdf-sparql-query/#scopeFilters

[[
A constraint, expressed by the keyword FILTER, is a restriction on 
solutions over the whole group in which the filter appears.
]]
Received on Monday, 24 January 2011 09:34:12 GMT

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