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Re: A little courtesy, please

From: John Cowan <jcowan@reutershealth.com>
Date: Wed, 24 May 2000 18:43:44 -0400
Message-ID: <392C5B20.977A0B1A@reutershealth.com>
To: Ray Whitmer <ray@xmission.com>, "xml-uri@w3.org" <xml-uri@w3.org>
Ray Whitmer wrote:

> > A fundamental difference is that absolutizing is a "quiet change", whereas
> > forbidding is noisy: existing documents get orphaned, as opposed to
> > existing systems starting to malfunction in unexpected ways.
> 
> I do not see absolutizing as quiet.  It causes lots of ambiguity about at
> what point a name is relative, at what point it is absolute, and with respect
> to what base, and can cause huge instability with nodes adopted from any
> source which one does not control. 

I think you misunderstand what I (and the ISO C Rationale) mean by a quiet change.
Here's a hypothetical (silly) example.

Suppose the maintainers of C decided that expressions of the form x++ were
a Bad Thing, and wanted to only allow ++x.  Generating an error when x++
is seen would be a noisy change.  Interpreting x++ as equivalent to ++x
henceforth would be a quiet change: the compiler would not complain, but
the semantics of the code would be very different.

In that sense, absolutizing is quiet, because it changes the semantics
(don't give me a hard time about that word, please) of relative namespace
names without notice.  Quiet changes are to be avoided, unless they really
have no effect on semantics at all.

-- 

Schlingt dreifach einen Kreis um dies! || John Cowan <jcowan@reutershealth.com>
Schliesst euer Aug vor heiliger Schau,  || http://www.reutershealth.com
Denn er genoss vom Honig-Tau,           || http://www.ccil.org/~cowan
Und trank die Milch vom Paradies.            -- Coleridge (tr. Politzer)
Received on Wednesday, 24 May 2000 18:44:07 UTC

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