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From: Bill Dubuque <wgd@martigny.ai.mit.edu>
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Date: Sun, 16 Feb 1997 16:42:52 -0500
To: kyle_jones@wonderworks.com
Cc: xemacs-beta@xemacs.org
Subject: Re: undo/redo models [was: Is your (favorite) package not in XEmacs and should be?]

: Date: Sun, 16 Feb 1997 13:15:12 -0500 (EST)
: From: Kyle Jones <kyle_jones@wonderworks.com>
: 
: Bill Dubuque writes:
:  > The debate over the various types of undo/redo models has a
:  > very long history. ... Thimbleby, Harold.  User interface design ...
: 
: Thumping down a 470 page book is kind of offputting when
: discussing an afternoon's hack, don'tcha think? :) Time
: constraints require that I take the hobbyist approach to most
: Emacs projects that I do, with perhaps VM being the only
: exception since I run mail systems for a living.  I leave it to
: the folks who hack Emacs for a living to decide whether undo/redo
: is worth including or not.  I'll be happy with the decision,
: either way.
: 
: I do appreciate the reference information.

My message was not intended to be critical of any particular
implementation or implementor -- rather my intent was merely to
supply background info for Hrvoje and any others who may not have
been around for all the earlier discussions.

The part of the book dealing with undo/redo is only a chapter or two 
and could surely be read in much less time than it would take to 
implement such functionality. The book is quite stimulating, and I 
recommend it to anyone with an interest in UI.

I can surely sympathize with your remarks about time constraints.
What (volunteer) Emacs implementor hasn't had to compromise due
to such?  If only we could find more corporate sponsors for Emacs.

-Bill Dubuque

