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From: David G. Durand <dgd@cs.bu.edu>
Date: Thu, 12 Jun 1997 13:09:12 -0500
Message-Id: <v03007801afc5e97e21d7@[]>
To: w3c-sgml-wg@w3.org
At 2:51 AM -0500 6/12/97, Martin Bryan wrote:
>At 21:15 11/6/97 -0500, David G. Durand wrote:
>>>There are many other cases where you need to invoke some outside interpreter
>>>to be able to understand what an element represents.
>>exactly, and currently it's a processing decision -- if you're not doing
>>_any_ procressing, then syntactic restrictions on the values don't really
>Are you claiming that an XML browser isn't doing _any_ processing? I thought
>that one of the things that distiguished XML applications from SGML parsers
>was that the XML application would always have some way of presenting the
>parsed data to the receiver:-)

I don't see a need for date arithmetic in browser style sheets (which is
the kind of thing that would make date validation essential).

I can imagine that a document might like to present dates in one of several
formats, and convert them to a common format for display, but this is
hardly essential for most applications. You don't need to verify PCDATA
unless you intend to invoke some sort of data format dependent process on
it. I think we could live without this verification (or implement it in
rendering code, eg. via applets).

I'm _not_ saying it's useless, but pointing out that in actual practice we
get by without PCDATA validation today (at the cost of custom coding it
when we do need it). I don't see why a "stripped down" SGML _requires_ this
feature, when SGML doesn't require it. I also don't see special web-related
issues here that wouls mandate the inclusion of such a feature. I'm not
even sure that we know what restrictions are needed. Some think regexps,
for instance, would be overkill, others have pointed out that many
constraints are not easily expressible with regexps. It would be a nice
feature, but we all know how to live without it.

   -- David (who's being grumpy about new features recently).

David Durand              dgd@cs.bu.edu  \  david@dynamicDiagrams.com
Boston University Computer Science        \  Sr. Analyst
http://www.cs.bu.edu/students/grads/dgd/   \  Dynamic Diagrams
--------------------------------------------\  http://dynamicDiagrams.com/
MAPA: mapping for the WWW                    \__________________________
Received on Thursday, 12 June 1997 13:32:04 UTC

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