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Re: pfps-04 (why the thread is germane to pfps-04)

From: Brian McBride <bwm@hplb.hpl.hp.com>
Date: 28 Jul 2003 15:57:14 +0100
To: "Peter F. "Patel-Schneider <pfps@research.bell-labs.com>
Cc: Martin Duerst <duerst@w3.org>, jjc@hplb.hpl.hp.com, Pat Hayes <phayes@ai.uwf.edu>, www-rdf-comments@w3.org
Message-Id: <1059404234.2139.87.camel@dhcp-91-3.hpl.hp.com>

Peter,

I'm going to interpret this as acceptance of the WG's disposition of
pfps-04:

[[
PS: Although the current situation may be technically satisfactory in
this area,
]]

Please speak up if this is not right.

Brian


On Fri, 2003-07-25 at 14:27, Peter F. Patel-Schneider wrote:
> From: Brian McBride <bwm@hplb.hpl.hp.com>
> Subject: Re: pfps-04 (why the thread is germane to pfps-04)
> Date: 25 Jul 2003 14:00:31 +0100
> 
> > On Fri, 2003-07-25 at 12:54, Peter F. Patel-Schneider wrote:
> > 
> > [...]
> > 
> > > Two XML literals are (now) equal in RDF precisely when their Exclusive
> > > XML Canonicalizations are the same octet sequence.
> > > 
> > > However other answers are harder to determine.
> > > 
> > > 1/ When is an XML literal equal to a plain RDF literal?  A plain RDF
> > > literal is a Unicode string (sequence of Unicode characters), so this
> > > question boils down to whether octets and Unicode characters are disjoint.
> > > I found it difficult to answer this question, because of hints in the
> > > exclusive canonicalization document that they are not.
> > 
> > I think we've established that UNICODE characters and octet sequences
> > are disjoint.  Martin, chair of the I18N group confirmed this in:
> >  
> > http://lists.w3.org/Archives/Public/www-rdf-comments/2003JulSep/0069.html
> > 
> > Whilst Martin does not like the RDFCore design, as currently specified
> > in the ed's drafts, XMLLiterals and plain literals are disjoint.
> > 
> > Pat has agreed to remove some misleading text, as noted in
> >  
> > http://lists.w3.org/Archives/Public/www-rdf-comments/2003JulSep/0067.html
> > 
> > > 
> > > 2/ When is an XML literal equal to an XML Schema string? 
> > 
> > As currently defined, never.  xsd:string's are not octet sequences, see
> > 
> > http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2003Jul/0043.html
> > 
> > Peter, how are we doing on pfps-04.  Have we resolved your comment?
> > 
> > Brian
> 
> I believe that a complete theory of equality for XML literals resolves this
> comment.  I suggest that several test cases be added to the RDF test suite.
> 
> The related issue of whether the value spaces of xsd:string and plain
> literals are disjoint also appears to be well on the way to resolution.  It
> is less urgent that the related issue of whether the values spaces of
> xsd:decimal and xsd:float, but this should also be addressed somewhere,
> perhaps only as a test case.
> 
> peter
> 
> PS: Although the current situation may be technically satisfactory in this
> area, the pain in getting there suggests that a slightly different
> description of XML literals might be more useful, perhaps something along
> the line of making the value space of XML literals in RDF be some abstract
> set with equality defined as per exclusive XML canonicalization and
> explicitly determined to be disjoint from the value space of plain RDF
> literals and also from the XSD value spaces.  This would also probably make
> the XML guys much more happy.
Received on Monday, 28 July 2003 10:59:25 GMT

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