RE: How are correct, unambiguous results possible with implementation-defined XML pre-processing?

At 01:23 PM 6/1/2007 -0400, Booth, David (HP Software - Boston) wrote:
>Chimezie,
>
>Your analysis is excellent, but it makes a key assumption that is simply
>incorrect, and seems to be the same key incorrect assumption that Murray
>has made, as evidenced by the minutes from this week's GRDDL
>teleconference:
>http://lists.w3.org/Archives/Public/public-grddl-wg/2007May/att-0104/200
>7-05-30-grddl-wg-minutes.html
>[[
>Murray: you cannot impose on someone to ingnore an XInclude in a
>document. Noone has the authority to do it
>]]
>
>They key question is: Are the semantics of an XML document governed by
>the root element namespace or are they not?  There is no gray area to
>this question.  They either are or they are not.  I essentially asked a
>more subtle version of this question in issue-dbooth-10, and DanC
>reported that the WG had already asked the TAG this question and the
>answer was yes:
>http://lists.w3.org/Archives/Public/public-grddl-wg/2007May/0071.html
>To be clear:
>
>     Rule #1: The semantics of an XML document are governed
>     by the root element namespace of that document.
>
>The point is that if rule #1 is true, then the GRDDL spec does not have
>the authority to permit an XML document's semantics to be *altered* by
>performing XML parsing that would be incorrect for that particular XML
>document.

You seem to be twisting our words to suit your argument.

The GRDDL spec neither permits nor forbids anything to do with 'semantics'.
The GRDDL spec operates on representations of information resources.
Purely mechanical. No knowledge of document semantics involved or implied.

A user-agent or user environment is subject to its own authority, not ours.

>Similarly, regarding Murray's statement above, if rule #1 holds, then
>the XML document's the root element namespace owner absolutely *does*
>have the authority to define the meaning of the syntax
>[[
>     <xi:include href="http://example.org/do-not-expand" />
>]]
>within the context of that document.

While such authority may exist in the mind of the TAG as it examines your 
document,
you have no practical authority to assert processing semantics over a document
that I have in my hand. So, if I choose to observe your processing 
semantics, you win.
However, if I, or anybody between you and I decides to change that document in
some way, then you may not get the same result as you would otherwise, and you
may never know the difference.

We concluded that the recipient of an XML document containing a new 
transformation,
or a transformation from a new namespace or profile, might want to examine
the transformation and decide what to allow the transformation to do or not do
according to local data security and integrity policies. The recipient 
might even want
to run the transformation in a walled-off sandbox to avoid inadvertent 
contamination.
A sophisticated GRDDL-aware agent or transformation might run the 
transformation
under different processing models and operating systems to yield different 
results
and then compare those results to decide which suited its taste. so to speak.

>Please note that there is a difference between an XML document and an
>XML Infoset.  Your line of reasoning seems to be subtly altering rule #1
>to: "The semantics of an XML Infoset are governed by the root element
>namespace of that Infoset".  But GRDDL was not chartered for producing
>RDF from an XML Infoset (though it is fine to do so as one *step* in
>producing RDF from an XML document).  GRDDL was charterd for producing
>RDF from an XML *document*.   The XML specification defines what
>constitutes an "XML document":
>http://www.w3.org/TR/REC-xml/#dt-xml-doc
>and it is defined in terms of characters -- not infoset.  (And
>incidentally, it corresponds to the WebArch notion of "representation"
>-- *not* "information resource".)

You keep coming back to the distinction between an XML Document and
an XML Infoset as though there was some significance. The only mention
of 'infoset' in GRDDL is in the informative section that warns about the
potential for missing information in an XML Document representation
of an information resource.

GRDDL operates on representations of information resources.

As to the group's charter, I believe that you should read it again:

"The mission of this Working Group is to complement the concrete RDF/XML 
syntax with a mechanism to relate other XML syntaxes (especially XHTML 
dialects or "microformats") to the RDF abstract syntax via transformations 
identified by URIs."

Under "Scope and Deliverables" it reads:

"[GRDDL] binds XML documents [...] to transformations [...] that relate 
their syntax to RDF/XML."

Following a careful reading of our charter, I am comfortable claiming that 
we have succeeded,
as are all of the other members of the WG. Your objections have been noted, 
reviewed and
discussed. No changes to the spec are forthcoming as a result of our review.

David, it is evident that you were hoping that someone would develop a spec 
that is
quite similar to GRDDL but distinctly different. I suggest that GRDDL could 
serve
as a model for another specification that works according to a different 
set of rules.
I encourage you to form a working group for that purpose.

Regards,

Murray

Received on Saturday, 2 June 2007 13:19:34 UTC