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Re: literals as numbers (Was: Re: Comments on SPARQL draft)

From: <jos.deroo@agfa.com>
Date: Thu, 4 Nov 2004 12:06:46 +0100
To: janne.saarela@profium.com
Cc: RDF Data Access Working Group <public-rdf-dawg@w3.org>, public-rdf-dawg-request@w3.org
Message-ID: <OF30466967.930277B5-ONC1256F42.003B601D-C1256F42.003D2579@agfa.com>

Fully agreed Janne (and we found a bug in our implementation :))

[] q:select { ?x :prop ?v};
   q:where {?x :prop ?v.
            ?v math:greaterThan "40"^^xsd:integer}.

should have no answer for data :x :prop "47".

-- 
Jos De Roo, AGFA http://www.agfa.com/w3c/jdroo/




Janne Saarela <janne.saarela@profium.com>
Sent by: public-rdf-dawg-request@w3.org
04/11/2004 11:46

 
        To:     RDF Data Access Working Group <public-rdf-dawg@w3.org>
        cc:     (bcc: Jos De_Roo/AMDUS/MOR/Agfa-NV/BE/BAYER)
        Subject:        Re: literals as numbers (Was: Re: Comments on SPARQL draft)



Seaborne, Andy wrote:
> Theer are two separate issues: matching in triple patterns and testing
> in comparisions.  Alberto illustrates the matching.  My opinion is that
> "47"^^xsd:integer and "47" do not represent the same value and so do not
> match in triple patterns and this is a reasonable expectation to the
> application writer.
>
>
> The plain literal case is more about comparison:
>
> ========== Data
>
> :x :prop "47" .
>
> ========== Query
>
> SELECT ?x WHERE (?x :prop ?v) AND ?v > 40

Ok, I think this is what I was looking for.

If SPARQL says it is forbidden to map plain literals
to typed literals, the query would never return
bindings for the given data above.

If SPARQL says it is optional for the implementation
to map plain literals to typed literals, the query might
return bindings for the given data above.

I think interoperability suffers via the optional route
and would be in favor of forbidding the mapping for plain literals.

Janne
--
Janne Saarela <janne.saarela at profium.com>
Profium, Lars Sonckin kaari 12, 02600 Espoo, Finland
Internet: http://www.profium.com
Received on Thursday, 4 November 2004 11:07:26 GMT

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