- From: Holger Knublauch <holger@topquadrant.com>
- Date: Tue, 18 Apr 2017 11:31:17 +1000
- To: "public-rdf-sha." <public-rdf-shapes@w3.org>
Hi Peter,
thanks for the updates. I had to make a further correction to one of
your files, which did not parse as valid Turtle. Meanwhile I have re-run
my tests and updated the results, showing two failures:
1) On the shared property shape test - we had discussed this topic
before - and my interpretation remains that the report should contain
the result twice. I have added a corresponding test case for that
variation. Moving forward I see the following options:
a) The spec is clear
- that only one have to be produced (in which case variation 2 is
removed)
- that two results have to be produced (in which case variation 1
is removed)
b) The spec leaves the interpretation open (in which case we should not
have a test case at all)
c) The spec has an error and we need to make adjustments
I have no strong opinion either way and don't believe this scenario will
happen often in practice.
2) The pre-binding question is probably beyond what most people here
understand so I have contacted Andy for his input.
I will put both topics on the agenda for the upcoming WG meeting.
Holger
On 17/04/2017 23:36, Peter F. Patel-Schneider wrote:
> On 04/16/2017 05:55 PM, Holger Knublauch wrote:
>> Hi Peter,
>>
>> thanks for submitting 3 new test cases [1]. I made a couple of syntactic
>> corrections which you can track on github. Among the more critical changes were:
>>
>> - the sh:value of the values.ttl test is ex:i, not 5, because the query does
>> not return ?value and in that case the engine reverts to using the value node
>> (which is the focus node in this case), see [2]
> Yes, I forgot to set value. Thanks for the fix, and the fix to
> sh:sourceConstraint.
>
> I added another test where both $this and ?value are set from one VALUES
> construct.
>
>> - I have deactivated the bind.ttl test case [3] because it is unclear what it
>> is supposed to demonstrate. My current Jena-based engine returns no violation
>> there, while your test seems to expect one violation. Could you explain the
>> motivation for the test and the reason for your expected result?
> This is a complex example.
>
> The empty BGP at the start of the query is removed because of the
> simplification step 18.2.2.8 so $this is not bound at the beginning of the
> query. The SELECT * WHERE { } does not bind $this because $this is not
> in-scope in it, even though $this has a value from the empty BGP in it.
> Because $this does not have a value the BIND leaves ?that unbound. Because
> ?that is unbound, the BGP matches against the triple ex:j a ex:bad in the
> data graph. As there is a solution there is a violation of the shape.
>
> I modified the test to use ?value instead of ?that and to return ?value to
> better utilize the behaviour of pre-binding.
>
>> - I have deactivated the shared.ttl test case [4] because it does not reflect
>> the SHACL spec. The given validation result expects that the sh:node
>> constraint is producing a violation with sh:ClassConstraintComponent as
>> sourceConstraintComponent. However, the validation of sh:node (as explained in
>> [5]) produces results with sh:NodeConstraintComponent as results. In other
>> words, the results only report on conformance of the sh:node, and do not
>> "walk" into it. Please feel free to submit an update to that test.
> Yes, I was incorrectly thinking that sh:node constraints also reported their
> component violations, not just an overall violation. I have modified the
> test to demonstrate the shared violation.
>
>> Regards,
>> Holger
>>
>>
>> [1]
>>
> https://github.com/w3c/data-shapes/pull/50/files/f857d2014900854ea1a0cf2ad498c9d0ae03cc0b..de60116e88470f51320e2442cce8698d7a44c6c8
>> [2] https://www.w3.org/TR/shacl/#sparql-constraints-variables
>> [3]
>>
> https://github.com/w3c/data-shapes/tree/gh-pages/data-shapes-test-suite/tests/sparql/pre-binding
>> [4]
>>
> https://github.com/w3c/data-shapes/tree/gh-pages/data-shapes-test-suite/tests/core/validation-reports
>> [5] https://www.w3.org/TR/shacl/#NodeConstraintComponent
>>
>
> peter
Received on Tuesday, 18 April 2017 01:31:53 UTC