W3C home > Mailing lists > Public > www-tag@w3.org > September 2002

Re: RDF Concepts and Data Model document

From: Tim Bray <tbray@textuality.com>
Date: Fri, 20 Sep 2002 15:29:42 -0700
Message-ID: <3D8BA156.6050401@textuality.com>
To: Tim Berners-Lee <timbl@w3.org>
Cc: "Williams, Stuart" <skw@hplb.hpl.hp.com>, Brian McBride <bwm@hplb.hpl.hp.com>, www-tag@w3.org

Tim Berners-Lee wrote:

> A.  to prohibit an RDF parser from taking such embedded RDF as being
> asserted by the document, without further information,
> N. Allow RDF parsers to "see through" any foreign XML as though it were
> transparent, and parse what is inside. This makes it impossible to define
> new XML tags to extend RDF into a more powerful language with any form of
> quotation, or "or" or "not" for example.

I agree that it's a good idea to provide a general-purpose mechansm to 
allow XML instances to signal that they believe the RDF assertions they 
contain, I don't understand at all why failure to do so makes it 
impossible to define new XML tags.

> I think the RDF core group has to address the  mixing of  RDF  with other
> languages. Every language spec should address namespace mixing.  We as a
> community have been rather lax about it, partly from lack of experience of
> how we want to do it.

Hmm, this is a tricky one, I've been kicking it around my head and it's 
not trivial at all.  Do you want to just signal that *all* RDF in an 
instance is to be believed, or do you want to individually bless chunks 
of RDF that may be found here or there?  For RDDL, you'd probably like 
to say globally "Please believe any & all embedded RDF", but one can 
imagine scenarios where you'd like to bless a particular package of 
assertions.

Also, do you want to require that such blessing be attached to the 
instance's root element?  Also not obvious.

Anyhow, a strawman, suppose you define some new markup in the RDF namespace.

rdf:blessAll="true" <== believe all RDF contained herein
rdf:bless="foo"     <== believe the embedded <rdf:rdf> element
                         with ID "foo"
rdf:blessings="bar" <== "bar" is the ID of an <rdf:blessings>
                         element which has an arbitrary number of
                         <rdf:bless id="foo"/> children indicating
                         other <rdf:rdf> elements to believe

  -Tim
Received on Friday, 20 September 2002 18:29:47 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Thursday, 26 April 2012 12:47:11 GMT