[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message]

Re: Web Resource Identity

  • From: David Megginson <david@m...>
  • To: Paul Prescod <paul@p...>
  • Date: Fri, 28 May 1999 14:23:49 -0400 (EDT)

Re: Web Resource Identity
Paul Prescod writes:
 > David Megginson wrote:
 > > 
 > > But you cannot always take two references and determine if they do
 > > *not* refer to the same object -- that depends on the design.
 > "Do these refer to the same object?" => Yes/No/Maybe
 > I'm not familiar with a system like that. Can you give an example?

You will often end up with two objects that represent conceptually the
same thing but cannot be proven equivalent (two medicare records, for
example); in fact, you may even have objects that share the same set
of attributes but cannot be proven equivalent.  There's also the case
of lazy Java programmers who don't override java.lang.Object.equals()
(that represents a significant percentage of existing Java code, I'd

 > Obviously boolean logic is MUCH easier to work with than tri-nary
 > logic.

No, in the case of URLs, it's still binary:

  "Are these known to refer to the same object?" => Yes/No

And while a cononical URL is an easy extension to HTTP, the
infrastructure to support it is another issue -- do I have to
guarantee, for example, that a gzipped tar file of the same version of
the Linux kernel source at two different mirrors return the same
canonical URL?

All the best,


David Megginson                 david@m...

xml-dev: A list for W3C XML Developers. To post, mailto:xml-dev@i...
Archived as: http://www.lists.ic.ac.uk/hypermail/xml-dev/ and on CD-ROM/ISBN 981-02-3594-1
To (un)subscribe, mailto:majordomo@i... the following message;
(un)subscribe xml-dev
To subscribe to the digests, mailto:majordomo@i... the following message;
subscribe xml-dev-digest
List coordinator, Henry Rzepa (mailto:rzepa@i...)


Purchasing Stylus Studio from our online shop is Easy, Secure and Value Priced!

Buy Stylus Studio Now

Download The World's Best XML IDE!

Accelerate XML development with our award-winning XML IDE - Download a free trial today!

Don't miss another message! Subscribe to this list today.
First Name
Last Name
Subscribe in XML format
RSS 2.0
Atom 0.3

Stylus Studio has published XML-DEV in RSS and ATOM formats, enabling users to easily subcribe to the list from their preferred news reader application.

Stylus Studio Sponsored Links are added links designed to provide related and additional information to the visitors of this website. they were not included by the author in the initial post. To view the content without the Sponsor Links please click here.

Site Map | Privacy Policy | Terms of Use | Trademarks
Free Stylus Studio XML Training:
W3C Member
Stylus Studio® and DataDirect XQuery ™are products from DataDirect Technologies, is a registered trademark of Progress Software Corporation, in the U.S. and other countries. © 2004-2013 All Rights Reserved.