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[XMLVersioning-41] Scope

From: Bjoern Hoehrmann <derhoermi@gmx.net>
Date: Tue, 22 Feb 2005 15:41:29 +0100
To: "David Orchard" <dorchard@bea.com>
Cc: www-tag@w3.org
Message-ID: <423f43f1.189345984@smtp.bjoern.hoehrmann.de>

* David Orchard wrote:
>I am interested in exploring language design beyond "simply" xml and xml
>schema, but I retain the worry that the more abstract the discussion,
>the smaller the audience or the less useful particular audiences will
>find the material.  The finding already is almost too general for my
>tastes as I believe that XML Schema is the most popular choice of schema
>language for xml design.

I am concerned about the scope of the TAG issue XMLVersioning-41 and
the draft findings so far. I think the scope should be generalized to
Protocol Evolution and Re-use with a focus on providing material that
will help protocol designers to make design decisions relative to these
issues.

The current focus on XML Versioning misses discussion of design issues
that were relevant to the design of XML 1.x and XML Namespaces 1.x; as
such issues are likely relevant to the design of protocols that are not
based on XML 1.x such as XPath, SPARQL, Notation3, N-Triples, XPointer,
XQuery, CSS, and (transcending from the bare syntax level) the DOM, it
is important to provide a broader perspective on these issues.

I think there is a common set of concepts and terminology that apply to
protocols independend of choice of specific syntax such as XML syntax,
and I consequently suggest that the first part of a finding on protocol
evolution and re-use provides a clear and detailed discussion of common
concepts and terminology including a general discussion of the impact
of design decisions relative to these concepts, without recommendations
towards making specific design decisions.

This would take into account that a major part of W3C's work does not
focus on the design of new XML-based document formats and that design
decisions relative to these issues vary greatly on a variety of factors,
for example, XML-based document formats for Business-to-Business SOAP-
based data-oriented Web Services are subject to different considerations
than formats developed in W3C's Interaction Domain.

This would provide a solid ground for all discussions around protocol
evolution which is indeed more important than how to use XML Namespaces
one way or the other. In particular, it is important to use common terms
to discuss such design issues, to cite just one example from the current
draft,

  A language change is backwards compatible if newer pro-
  cessors can process all instances of the old language.

This is not how many people use this term, it is often used to mean

  A language change is backwards compatible if old pro-
  cessors can process most instances of the new language.

The second part of the finding should discuss these concepts relative to
the design of XML as an architectural platform and design considerations
for XML-based formats relative to these concepts, again including a dis-
cussion of the impact of specific design decisions. This would include
use of XML Namespaces in XML document formats and use of HTTP to trans-
port XML document formats in the context of evolving formats and should
strive to build consensus around some of the relevant concepts as far as
that would be beneficial (and I suggest that for many of the suggested
good practises that does not apply.)

If the TAG is really considered the best place to develop W3C XML Schema
Primers there could be a third part discussing how to implement design
decisions based on the other parts of the finding and general W3C XML
Schema authoring guidelines, but I suggest it be dropped.
-- 
Björn Höhrmann · mailto:bjoern@hoehrmann.de · http://bjoern.hoehrmann.de
Weinh. Str. 22 · Telefon: +49(0)621/4309674 · http://www.bjoernsworld.de
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Received on Tuesday, 22 February 2005 14:42:05 GMT

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