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Empty <rdf:RDF> [was Re: About Refactoring RDF/XML Syntax Rivision 1.43 ]

From: Dave Beckett <dave.beckett@bristol.ac.uk>
Date: Thu, 06 Sep 2001 17:19:52 +0100
To: w3c-rdfcore-wg <w3c-rdfcore-wg@w3.org>
CC: Jeremy Carroll <jjc@hplb.hpl.hp.com>
Message-ID: <5705.999793192@tatooine.ilrt.bris.ac.uk>
>>>Jeremy Carroll said:
> My point is expressed by an example like
> 
> <rdf:RDF xml:lang="fr" xmlns:rdf="..." />
> 
> which does not match the production 4.2/6.1, while being a legal empty RDF
> graph.

I suspect you meant a legal empty RDF graph en Franšais? :)
But lets not go there just at this point.

The original grammar production 6.1 does not match but because the
grammar in RDF M&S also has some prose additions about xml:lang
(xmlns:rdf never enters the infoset).  It is legal because of that.
The new 4.2 does not match since I still haven't merged those words
into the formal productions.

You are assuming <rdf:RDF>...</rdf:RDF> is required (which looks like
something we are going to change the grammar to be) and defines
the scope of an RDF graph, maybe inside a large XML document.

RDF M&S 1.0 says:

  The RDF element is a simple wrapper that marks the boundaries in an
  XML document between which the content is explicitly intended to be
  mappable into an RDF data model instance. The RDF element is
  optional if the content can be known to be RDF from the application
  context.
  -- http://lists.w3.org/Archives/Public/www-archive/2001Jun/att-0021/00-part#54

At present we seem to be heading to change this to something like

  <rdf:RDF> marks the boundary of an RDF graph and is a required element.

but with more flowery words, and changing WD-to-be production 4.2 to
match that, generate a good / bad test case.

Dave
Received on Thursday, 6 September 2001 12:20:01 EDT

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