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Re: yet another sidetrack on what a URI identifies

From: Dan Connolly <connolly@w3.org>
Date: Fri, 24 Jan 2003 10:56:08 -0600
To: Tim Berners-Lee <timbl@w3.org>
Cc: "Roy T. Fielding" <fielding@apache.org>, Sandro Hawke <sandro@w3.org>, www-tag@w3.org
Message-id: <1043427367.24068.57.camel@dirk.dm93.org>

On Thu, 2003-01-23 at 23:33, Tim Berners-Lee wrote:
> On Tuesday, Jan 14, 2003, at 19:58 US/Eastern, Roy T. Fielding wrote:
[...]
> > I know why your model breaks.  Try describing caching.
> 
> Ok, Roy, so using my model or Sandro's, show  why when you
> try to describe caching it breaks.
> 
> >   For real,
> > not in your imagination, but on paper and with appropriate definitions
> > for the metadata that is included in HTTP responses so that the
> > client has an interoperable clue as to what you are talking about.
> > Then try describing hierarchical proxies, gateways, etc.  And if you
> > are willing to continue work on that model, use it to describe the
> > semantics of a Web to GSM SMS gateway using POST.  I already did that
> > stuff seven years ago,
> 
> If you have it in the form of a formal system, then I think
> a pointer to it would be very interesting.   I know Dan Connolly did
> some work in Larch,

Yes; at the May 2000 web conference, I presented

  Specifying Web Architecture with Larch
  http://www.w3.org/2000/Talks/www9-larch/all.htm

which traces my thoughts on formalizing the web from
discussions with Burchard and company circa 1995,
problems with that simple model, fixes to various problems,
culminating in a model of HTTP caching that, after discussion with TimBL
and others, I find quite satisfactory...


  http://www.w3.org/XML/9711theory/HTTP
  http://www.w3.org/XML/9711theory/HTTP.html
  http://www.w3.org/XML/9711theory/HTTP.lsl

specifically, the bit about...
	% The Conditional GET Axiom, If_Modified_Since case
	% c.f.
%html Ari Luotonen and Kevin Altis<br />
%html <cite><a href='http://www1.cern.ch/PapersWWW94/luotonen.ps'>World-Wide Web Proxies</a></cite><br />
%html Proceedings of the 1st International WWW Conference, May 1994.



The larch traits that I use to do my thinking about
web architecture
  http://www.w3.org/XML/9711theory/

cover a variety of issues, from URI syntax
  http://www.w3.org/XML/9711theory/URIclient.lsl
to RDF model theory
  http://www.w3.org/XML/9711theory/RDFAbSyn.lsl
to transcribing (and finding a small bug in)
Wadler's 1999 formalization of XPath/XSLT
  http://www.w3.org/XML/9711theory/XPathWadler

Perhaps more evidence that TimBL and I are not just
talking is the URI syntax implementation we've worked
on, including some test cases that represent issues
with RFC2396. I'm not sure we've reported them all
yet...

  http://www.w3.org/2000/10/swap/uripath
  http://www.w3.org/2000/10/swap/uripath.py
  http://www.w3.org/2000/10/swap/uripath.html

Actually, timbl and I haven't quite reached
consensus on whether relative URI references
are allowed in some parts of the uripath API.

But our discussions are very much based on running
code, machine-checked formalisms, and real-world
applications... such as automation of the W3C
digital library
  http://www.w3.org/2002/01/tr-automation/
and managing my own personal travel itineraries
  http://www.w3.org/2000/10/swap/pim/travel.html
  http://www.w3.org/2003/02dc-sna/itin1.rdf
  http://www.w3.org/2003/02dc-sna/itin1.png
  http://www.w3.org/2003/02dc-sna/itin1b.txt
  http://www.w3.org/People/Connolly/events/

As TimBL mentioned, cwm implements the integration
of all this stuff... connecting KR to WWW. The
log:semantics primitive in cwm is a simpler model
than the 9711theory/HTTP model... but I think
it's a useful simplification, the way Newtonian
physics is a useful simplification of relativistic
physics. I hope to elaborate on that analogy
sometime between now and our Feb ftf...


> > so I expect a little more than talk at this
> > point from the W3C.

It's tricky to manage the balance between development
and "talk" here in www-tag. I'll thank you not to
jump to conclusions, assuming we're only talking,
and to trust that we're each doing our level best
to be constructive.


-- 
Dan Connolly, W3C http://www.w3.org/People/Connolly/
Received on Friday, 24 January 2003 11:57:40 GMT

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