- From: Bijan Parsia <bparsia@cs.man.ac.uk>
- Date: Thu, 17 Aug 2006 11:06:17 +0100
- To: andy.seaborne@hp.com
- Cc: Pat Hayes <phayes@ihmc.us>, RDF Data Access Working Group <public-rdf-dawg@w3.org>
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. 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. """
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?
> ==== Test 2
>
> arq.qexpr "isLiteral('-5'^^xsd:positiveInteger)" ==> true
>
> 10:06:46 WARN NodeValue
> Datatype format exception: "-5"^^xsd:positiveInteger
> true
But the isLiteral evaluation is correct.
> The warnings are execution logging warnings and do not affect the
> results.
> It is trying to consider things as one of the understood types/
> values, and falling back to a plain RDF literal (but not it's value).
I don't know exactly what that means for the example above.
Cheers,
Bijan.
Received on Thursday, 17 August 2006 10:06:54 UTC