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Re: Test cases: XML Literal value space and exclusive canonicalization

From: Dave Beckett <dave.beckett@bristol.ac.uk>
Date: Thu, 7 Aug 2003 11:08:44 +0100
To: Martin Duerst <duerst@w3.org>
Cc: www-rdf-comments@w3.org, pat hayes <phayes@ihmc.us>, Benja Fallenstein <b.fallenstein@gmx.de>, Jeremy Carroll <jjc@hplb.hpl.hp.com>, w3c-rdfcore-wg@w3.org, w3c-i18n-ig@w3.org, msm@w3.org
Message-Id: <20030807110844.270875b0.dave.beckett@bristol.ac.uk>

On Mon, 04 Aug 2003 13:55:25 -0400
Martin Duerst <duerst@w3.org> wrote:

<snip/>
> So it seems to be true, for simple datatype literals, that
> 
> Abstract syntax == lexical value ~= representation in RDF/XML
> 
> (the ~= including generic issues such as character escaping,
> but no datatype-specific issues).

Yeah, sort of.  And the Unicode characters in the lexical form that
can't be written in XML.

<snip/>
 
> Is every RDF application required to support XML Literals?
> Or only the syntactic parts, and the RDF/XML to Graph conversion
> (including canonicalization) if appropriate?

Only those that deal with mapping between the abstract syntax and the
XML syntax (either direction).  

The "pure" RDF applications work on graphs and need have no XML-specific
code.  XML Literals just look like any other datatype to RDF graph
applications and should need no extra support in the graph.

<snip/>


> Sorry, my mistake. This should read:
> 
> <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
>            xmlns:eg="http://example.org/"
>            xmlns:eg2="http://example.com/">
>    <rdf:Description rdf:about="http://example.org/foo">
>      <eg:bar rdf:parseType="Literal"><eg2:br/></eg:bar>
>    </rdf:Description>
> </rdf:RDF>
> 
> (i.e. with <eg2:br/> instead of <eg:br/>)

comparing to:

> > > > > <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
> > > > >           xmlns:eg="http://example.org/">
> > > > >   <rdf:Description rdf:about="http://example.org/foo">
> > > > >     <eg:bar rdf:parseType="Literal"><eg2:br
> > > > > xmlns:eg2="http://example.com/"></eg2:br></eg:bar>
> > > > >   </rdf:Description>
> > > > > </rdf:RDF>
> > > > >
> > > > > My reading of the current spec is that both examples produce
> > > > > the same graph, and that the canonicalization (and therefore,
> > > > > according to the discussion above, the literal value) of
> > > > > the literal in the graph is:
> > > > >
> > > > > "<eg2:br xmlns:eg2="http://example.com/"></eg2:br>"
> > > > >
> > > > > If this is not true, please tell me what happens in the
> > > > > above case.

<snip/>
> Okay, then with the corrected example, they will be the same, yes?

Yes, both produce the same literal value, as given above
(well, the " need quoting.  In N-triples:
  "<eg2:br xmlns:eg2=\"http://example.com/\"></eg2:br>"
)

Dave
Received on Thursday, 7 August 2003 06:09:17 EDT

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