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Re: Re: Request for two new media types submitted

From: Eric Prud'hommeaux <eric@w3.org>
Date: Tue, 16 Dec 2008 13:13:24 -0500
To: Stasinos Konstantopoulos <konstant@iit.demokritos.gr>
Cc: Phil Archer <phil@philarcher.org>, Bjoern Hoehrmann <derhoermi@gmx.net>, Public POWDER <public-powderwg@w3.org>, Ivan Herman <ivan@w3.org>, Ralph Swick <swick@w3.org>
Message-ID: <20081216181324.GW5762@w3.org>
* Stasinos Konstantopoulos <konstant@iit.demokritos.gr> [2008-12-10 23:32+0200]
>
> Eric, hi.
>
>
> On Dec 8, 2008, at 5:30 PM, Eric Prud'hommeaux wrote:
>
>> Minor nit:
>> [[
>>  We extend RDF with the datatype properties ...
>> ]] — http://www.w3.org/TR/2008/WD-powder-formal-20081114/#SE
>>
>> would imply to me that the RDF machinery must be extended, as opposed
>> to the application interpreting the RDF graph. Maybe something like:
>> "POWDER-S uses an <a 
>> href="http://www.w3.org/TR/2004/REC-owl-semantics-20040210/syntax.html#owl_DatatypeProperty_syntax 
>> ">OWL DatatypeProperty</a> to relate a resource to a regular  
>> expression which that resource matches. While POWDER-S uses OWL  
>> classes to group resources, any engine determining if a resource  
>> belonged in one of these OWL classes would need to be able to test a  
>> resource against a regular expression."
>
> No, not at all, it is the underlying RDF representation where the
> explicit data lives that is being extended; the inference layer is
> not affected. Of course inference engines that directly manipulate
> RDF data need to implement the extension, but in situations where a
> clean interface exists between the two, the inference engine does
> not need to know why the wdrs:matchesregex triples are asserted.

An unextended RDF parser, database, and SPARQL query engine can parse,
store and return assertions like:
  _:redRestriction wdrs:matchesregex "^http://foo.example/redStuff.*" .
  <http://foo.example/redStuff/redShoe> wdrs:matchesregex "^http://foo.example/redStuff.*" .

Telling people that they require an extended RDF is misleading.


I also noticed
[[
  <owl:Class rdf:nodeID="iriset_1">
    <owl:equivalentClass>
      <owl:Class>
        <owl:intersectionOf rdf:parseType="Collection">
          <owl:Restriction>
            <owl:onProperty rdf:resource="http://www.w3.org/2007/05/powder-s#matchesregex" />
            <owl:hasValue rdf:datatype="http://www.w3.org/2001/XMLSchema#string">\:\/\/(([^\/\?\#]*)\@)?([^\:\/\?\#\@]+\.)?(example\.com)(:([0-9]+))?\/</owl:hasValue>
          </owl:Restriction>
        </owl:intersectionOf>
      </owl:Class>
    </owl:equivalentClass>
  </owl:Class>
]] — http://www.w3.org/TR/powder-dr/#eg2-3
which is an intersection of one class. How about this instead?
[[
  <owl:Class rdf:nodeID="iriset_1">
    <owl:equivalentClass>
      <owl:Restriction>
        <owl:onProperty rdf:resource="http://www.w3.org/2007/05/powder-s#matchesregex" />
        <owl:hasValue rdf:datatype="http://www.w3.org/2001/XMLSchema#string">\:\/\/(([^\/\?\#]*)\@)?([^\:\/\?\#\@]+\.)?(example\.com)(:([0-9]+))?\/</owl:hasValue>
      </owl:Restriction>
    </owl:equivalentClass>
  </owl:Class>
]] — http://www.w3.org/TR/powder-dr/#eg2-3

Should I submit this as a separate issue? Is there an issues list?

> See also
> http://lists.w3.org/Archives/Public/public-powderwg/2008Dec/0044.html
>
> s

-- 
-eric

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Received on Tuesday, 16 December 2008 18:14:41 GMT

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