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Re: Use of XSD namespace in RDF recommendations

From: Richard Cyganiak <richard@cyganiak.de>
Date: Tue, 4 Sep 2012 20:36:57 +0100
Cc: public-rdf-comments Comments <public-rdf-comments@w3.org>
Message-Id: <352B45C6-34F4-407D-90FE-8E7227E27582@cyganiak.de>
To: Ivan Herman <ivan@w3.org>, Antoine Zimmermann <antoine.zimmermann@emse.fr>, Dan Brickley <danbri@danbri.org>, Richard Smith <richard@ex-parrot.com>, Jeremy Carroll <jeremy@topquadrant.com>
Ivan, Antoine, Dan, Richard, Jeremy,

I guess I like the idea of informatively linking to both the 2006 SWBP Note on datatypes [1] and to the OWL 2 datatype definition mechanism [2], stating that both XML Schema and OWL 2 provide facilities for formally defining RDF datatypes, but that support for neither mechanism is required for RDF.

Jeremy: Is [1] still considered up-to-date, or should we avoid drawing attention to it?

Antoine, Ivan, Dan: Perhaps one of you wants to take a stab at drafting a sentence that could be inserted into the Datatypes section [3] as another Note?


[1] http://www.w3.org/TR/swbp-xsch-datatypes/
[2] http://www.w3.org/TR/owl2-syntax/#Datatype_Definitions
[3] http://dvcs.w3.org/hg/rdf/raw-file/default/rdf-concepts/index.html#section-Datatypes

On 4 Sep 2012, at 18:38, Ivan Herman wrote:

> Dan,
> the question is of course justified, but I should also add that, in fact, very very few people use xmls schema datatype definitions together with RDF, too. In both cases the difficulty is identical: to understand and process those datatypes an external 'tool' has to be brought in: either an xml schema or an owl processor... Mainly in a non-XML RDF world (ie, as Richard said, with a diminishing usage of RDF/XML) the chance of using XML schema based derived datatypes is getting smaller and smaller in my view.
> I find the OWL 2 datatype definition possibilities one of the most interesting and potentially important part of OWL 2. I actually wish the relevant part of the specification was also made more known and possibly used in isolation; at present it is burried in the overall OWL 2 spec, which is of course not an easy read...
> (Maybe it is worth some extra blog/note)
> Ivan
> ---
> Ivan Herman
> Tel:+31 641044153
> http://www.ivan-herman.net
> (Written on mobile, sorry for brevity and misspellings...)
> On 4 Sep 2012, at 15:37, Dan Brickley <danbri@danbri.org> wrote:
>> On 4 September 2012 21:11, Antoine Zimmermann
>> <antoine.zimmermann@emse.fr> wrote:
>>> FWIW, OWL 2 has a feature to define custom datatypes that can be written
>>> completely in RDF, without using XML Schema.
>>> Your example for Chapman codes can be written as follows, in Turtle syntax:
>>> @prefix geo: <http://www.example.com/geo#>
>>> @prefix xsd: <http://www.w3.org/2001/XMLSchema#>
>>> @prefix owl: <http://www.w3.org/2002/07/owl#>
>>> @prefix rdfs:<http://www.w3.org/2000/01/rdf-schema#>
>>> geo:chapman-code  a  rdfs:Datatype;
>>>   owl:equivalentClass  [
>>>       a  rdfs:Datatype;
>>>       owl:onDatatype  xsd:string;
>>>       owl:withRestriction ( [xsd:pattern "[a-zA-Z]{3}"] )
>>>   ] .
>> Interesting! Are many of these showing up "in the wild" yet?
>> Dan
Received on Tuesday, 4 September 2012 19:37:27 UTC

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