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Re: Proposal to resolve two XSD datatype issues

From: Ivan Herman <ivan@w3.org>
Date: Thu, 10 May 2012 09:48:21 +0200
Cc: RDF Working Group WG <public-rdf-wg@w3.org>
Message-Id: <04E9903C-059A-4FFC-B8F9-56D478090BDC@w3.org>
To: Richard Cyganiak <richard@cyganiak.de>

On May 10, 2012, at 01:42 , Richard Cyganiak wrote:

> PROPOSAL: Close ISSUE-87 without further action
> 
> PROPOSAL: Resolve ISSUE-88 by adding xsd:duration to the list of supported XSD datatypes in RDF 1.1

+1

Ivan

> 
> Details/justifications below.
> 
> Best,
> Richard
> 
> 
> == ISSUE-87 ==
> 
> [[
> Some RDF datatypes included in RDF 2004, such as xsd:gYear, have proven troublesome in RIF and OWL due to not being well-behaved w.r.t. ordering. Revisit them to decide if anything is to be done about it.
> ]]
> http://www.w3.org/2011/rdf-wg/track/issues/87
> 
> Ivan said:
>> I do not see why we would have to do that. These datatypes are obviously useful in RDF and, actually, are used (eg, the microdata->RDF specification recommends using those). OWL and RIF has good reasons not to use them, but that is not binding for RDF imho.
> 
> 
> http://lists.w3.org/Archives/Public/public-rdf-wg/2012May/0051.html
> 
> Hence the proposal.
> 
> 
> == ISSUE-88 ==
> 
> [[
> RDF 2004 says that xsd:duration does not have a well-defined value space. The value space of xsd:duration has been re-defined in XML Schema 1.1, so this needs to be revisited.
> ]]
> http://www.w3.org/2011/rdf-wg/track/issues/88
> 
> Alex Hall reviewed this (Thanks Alex!) and said:
> 
> [[
> The duration definition in XSD 1.1 does have a clearly defined:
>    lexical space, which is the same as that in 1.0
>    value space, which is modeled as a [ months as xsd:integer, seconds
>     as xsd:decimal ] tuple.
>    identity condition: two durations are identical if and only if their
>     months and seconds components are both identical.
>    equality relation, which is the same as its identity relation.
>    partial ordering.
> 
> Given these revisions, we should consider including xsd:duration in the
> list of RDF-compatible XSD types.
> ]]
> http://lists.w3.org/Archives/Public/public-rdf-wg/2012Feb/0039.html
> 
> Peter went and asked the OWL, RIF and SPARQL WGs to check for objections (Thanks Peter!):
> http://www.w3.org/mid/4FA15CC4.4090900%2540gmail.com
> 
> This generated quite some chatter, but the only substantive technical comments on the issue came from Michael Schneider, who summarised his position here:
> http://lists.w3.org/Archives/Public/public-owl-wg/2012May/0044.html
> 
> As our intention is to only add xsd:duration to the XSD datatype map (which is optional), Michael's view can be summarized as:
> 
> [[
> Why should we (the OWL WG) care about xsd:duration? It'll be just yet another datatype that is in RDF but not in OWL 2 and RIF.
> ]]
> http://lists.w3.org/Archives/Public/public-owl-wg/2012May/0044.html
> 
> Which is a view that was also expressed by Pat and others in one of our recent calls.
> 
> Hence the proposal.
> 
> The required document change is simply to do the obvious thing in this section of RDF Concepts ED:
> http://dvcs.w3.org/hg/rdf/raw-file/default/rdf-concepts/index.html#xsd-datatypes


----
Ivan Herman, W3C Semantic Web Activity Lead
Home: http://www.w3.org/People/Ivan/
mobile: +31-641044153
FOAF: http://www.ivan-herman.net/foaf.rdf
Received on Thursday, 10 May 2012 07:45:30 GMT

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