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Re: Proposal to resolve two XSD datatype issues

From: Peter F. Patel-Schneider <pfpschneider@gmail.com>
Date: Thu, 10 May 2012 04:53:58 -0400
Message-ID: <4FAB8226.9020804@gmail.com>
To: Richard Cyganiak <richard@cyganiak.de>, public-rdf-wg <public-rdf-wg@w3.org>
I find it very strange to endorse xsd:duration but notxsd:yearMonthDuration 
<http://www.w3.org/TR/xmlschema11-2/#yearMonthDuration> or xsd:dayTimeDuration 
<http://www.w3.org/TR/xmlschema11-2/#dayTimeDuration> which are defined from 
xsd:duration (and are better behaved).  I suggest modifying the second 
proposal to include these two datatypes.  Also, there are no supported XSD 
datatypes in RDF!  You probably meant "suitable" or "in the XSD datatype map".

The treatment of dates and time has changed significantly between XSD 1.0 and 
XSD 1.1.   The RDF WG may want to determine whether the revised datatypes are 
suitable for use in RDF before closing ISSUE-87.

peter


On 05/09/2012 07:42 PM, 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
>
> 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
Received on Thursday, 10 May 2012 08:54:30 GMT

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