- From: Bijan Parsia <bparsia@cs.man.ac.uk>
- Date: Thu, 17 Aug 2006 12:46:57 +0100
- To: andy.seaborne@hp.com
- Cc: Pat Hayes <phayes@ihmc.us>, RDF Data Access Working Group <public-rdf-dawg@w3.org>
On Aug 17, 2006, at 12:39 PM, Seaborne, Andy wrote:
> Bijan Parsia wrote:
>> Thanks Andy, that was interesting.
>> On Aug 17, 2006, at 10:20 AM, Seaborne, Andy wrote:
>>> Output from ARQ (using the standalone expression evaluator
>>> because it explains what is going on; ASK queries mask this):
>>>
>>> Reformatted for email.
>>>
>>> ==== Test 1
>>>
>>> arq.qexpr "'-5'^^xsd:positiveInteger < 5" ==> error
>>>
>>> 10:06:46 WARN NodeValue
>>> Datatype format exception: "-5"^^xsd:positiveInteger
>>> Exception: Can't compare "-5"^^<http://www.w3.org/2001/
>>> XMLSchema#positiveInteger> and 5
>> You say that the warnings do not affect the results.
>
> Warnings are output as logging messages. Ignore then for the value
> of the expression. ARQ just outputs some logging stuff for caes
> where the user may find it useful. As ARQ (and Jena and Joseki)
> uses Jakarta Commons Logging (and log4j usually) the user/app can
> pick and choose logging messages anyway.
>
> > But this is
>> wrong behavior, yes?
>> """Specifically, FILTERs eliminate any solutions that, when
>> substituted into the expression, result in either an effective
>> boolean value of false or produce an error. """
>
> This is showing the result of an expression evaluation, not the
> full filter evaluation. That's why I didn't use an ASK query.
Ok, but surely the relevant bit is how this expression evaluation
affects filter evaluation.
> Andy
>
>> So, given data
>> :b :p "-5"^^xsd:positiveInteger.
>> :b :q "5"^^xsd:positiveInteger.
>> and query
>> SELECT ?x {?x :p ?L1. ?x :q ?L2. FILTER ?L1 < ?L2}
>> ARQ returns
>> ?x/:b
>> instead of no answers?
Hence wondering what ARQ does in this specific case.
Cheers,
Bijan.
Received on Thursday, 17 August 2006 11:47:36 UTC