[comp.emacs] How to re-do undo's ...

chan@UUNET.UU.NET (Milo Chan) (10/18/90)

There has been much recent discussion about how to undo changes in GNU
Emacs.  C-_ can undo recent changes.  When Emacs has undone all that it
remembers (when it has reached the end of the change history), it reverses
the undo direction, and 're-does' the changes it just 'undid', one step at
a time.

QUESTION: Is there any way to reverse the direction of the undo without
going 'all the way back' to the end of the change history first?  

Sometimes I need to undo a sequence of changes, and I undo *one step too
far*.  It would be nice not to have to cycle all the back to the end of
the change history to re-do an accidental undo.

-Milo Chan, Lehman Brothers Division, Shearson Lehman Brothers, Inc.
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xtt@mace.cc.purdue.edu (Michal Jankowski) (10/19/90)

Actually, it is easy to 're-do' unwanted 'un-do'.
If you decide that you did, say, two 'un-do's too many, just
type any cursor-movement command (say, ^F or right-arrow)
and press C-_ twice. It will undo last two changes, which happen
to be 'un-do's, in effect re-doing them.

  Michal Jankowski

jpayne@flam.Eng.Sun.COM (Drummer Boy) (10/19/90)

In article <5806@mace.cc.purdue.edu> xtt@mace.cc.purdue.edu (Michal Jankowski) writes:
>Actually, it is easy to 're-do' unwanted 'un-do'.
>If you decide that you did, say, two 'un-do's too many, just
>type any cursor-movement command (say, ^F or right-arrow)
>and press C-_ twice. It will undo last two changes, which happen
>to be 'un-do's, in effect re-doing them.
>
>  Michal Jankowski


Yeah, but then your edit history becomes full of undos, which are
not useful or helpful things to have lying around in the undo
history.  Pretty soon you can't tell what is going to happen when
you hit UNDO.

MAP@LCS.MIT.EDU (Michael A. Patton) (10/21/90)

   From: slcpi!dev07123!chan@uunet.uu.net (Milo Chan)
   Date: Thu, 18 Oct 90 10:36:54 EDT

   QUESTION: Is there any way to reverse the direction of the undo without
   going 'all the way back' to the end of the change history first?  

If you type some command other than undo---I tend to use C-A---that
breaks the chain of undos.  Now if you type undo (C-_) again, it
undoes the last change.  In this case the last change is the last undo
from the previous sequence.  In effect this redoes the original change.
Watch out, if you redo several then make some other changes and decide
to use undo to get back to some other intermediate state you may
confuse yourself, I've occasionally done this so much my brain started
hurting :-).

chan@UUNET.UU.NET (Milo Chan) (10/25/90)

Thanks to all who responded with the solution do re-doing undo's (pressing
any other key to reverse the undo sequence).
(Thank you also for not responding with any RTFM's!)  :-)


-Milo Chan, Shearson Lehman Brothers, Inc.
+----------------------------------+---------------------------------------+
|Mail: Shearson Lehman Brothers    |EMail: ...uunet!slcpi!dev07123!chan    |
|      388 Greenwich St., 11th Flr.|     "slcpi!dev07123!chan"@uunet.UU.NET|
|      New York, NY 10007, USA     |      chan@fractl.tn.cornell.edu       |
|Voice: (212) 464-3808             |Fax:   (212) 464-3011                  |
+----------------------------------+---------------------------------------+