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RE: Concern about limiting allowed dataranges in DatatypeRestriction (for ACTION-83)

From: Michael Schneider <schneid@fzi.de>
Date: Wed, 6 Feb 2008 23:24:00 +0100
Message-ID: <0EF30CAA69519C4CB91D01481AEA06A06C30B7@judith.fzi.de>
To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
Cc: <public-owl-wg@w3.org>, <msmith@clarkparsia.com>
Peter wrote:

>Although the nesting does not add expressive power, I would prefer that
>the nested syntax also be allowed, in part because this would 
>mirror XML
>Schema datatypes (which has a notion of the underlying datatype) and in
>part because it would pave the way for sharing parts of data range
>constructs.
>
>peter

Perhaps the following idea would work: Nesting is allowed, if it can be
syntactically transformed into an equivalent allowed "flat" expression.
Michaels example below would be of such a kind.

So nested datarange restrictions would just be syntactical sugar for the
flat ones. I expect that the transformation rules are rather
straightforward. In order to know whether a facet in such a nested
expression is allowed and what it means, one could then just do the
transformation and lookup the meaning for the equivalent flat expression. 

Cheers,
Michael

>From: Michael Smith <msmith@clarkparsia.com>
>Subject: Concern about limiting allowed dataranges in 
>DatatypeRestriction (for ACTION-83)
>Date: Wed, 06 Feb 2008 15:53:18 -0500
>
>> To meet obligations of ACTION-83:
>> 
>> In today's telecon, Boris was arguing for restricting the allowable
>> dataranges in datatypeRestriction.  In particular, he was citing
>> problematic examples like
>> 
>> DatatypeRestriction ( DataComplementOf ( xsd:integer ) 
>minInclusive 5 )
>> 
>> I agree that no use case has been provided for this example, but was
>> concerned because limiting the construct to only datatypeURI would
>> prevent "nesting" datatype restrictions, such as:
>> 
>> DatatypeRestriction ( DatatypeRestriction ( xsd:decimal ) 
>minInclusive
>> 5.0 ) maxInclusive 6.0 )
>> 
>> Upon re-evaluating the constructs in light of the change to DataRange
>> made for [ISSUE-28] on 2008-11-21 [1], I see that this can 
>be expressed
>> without nesting as in:
>> 
>> DatatypeRestriction ( xsd:decimal  minInclusive 5.0 
>maxInclusive 6.0 )
>> 
>> So, having clarified the current state of the draft, my concern is
>> resolved and I support Boris' proposal to limit 
>DatatypeRestriction to
>> datatypeURI.
>> 
>> Thank you Boris for addressing my concern 3 months ago!
>> 
>> -- 
>> Mike Smith
>> 
>> Clark & Parsia
>> 
>> [ISSUE-28] http://www.w3.org/2007/OWL/tracker/issues/28
>> [1] 
>http://www.w3.org/2007/OWL/wiki/index.php?title=Syntax&diff=134
>1&oldid=1327
>> 
>> 
>
>

--
Dipl.-Inform. Michael Schneider
FZI Forschungszentrum Informatik Karlsruhe
Abtl. Information Process Engineering (IPE)
Tel  : +49-721-9654-726
Fax  : +49-721-9654-727
Email: Michael.Schneider@fzi.de
Web  : http://www.fzi.de/ipe/eng/mitarbeiter.php?id=555

FZI Forschungszentrum Informatik an der Universität Karlsruhe
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Received on Wednesday, 6 February 2008 22:24:22 GMT

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