Re: Unhiding edited areas

[Martin Pohlack <mp26@os.inf.tu-dresden.de>]

Hi Samuel,

Samuel Wales wrote:
> Hi Martin,
> 
> This is a huge issue.[1]
> 
> Here is what I do to try to work around it.
> 
> I use git, to limit the damage from confusion.

Yes, this or a versioning filesystem is probably advisable.

> I expand the entire buffer if I think I am about to be confused.
> 
> ;;i like the idea of clustering undo but find it disconcerting
> (setf org-self-insert-cluster-for-undo nil)
> ;;somebody, I think Carsten, suggested this, and it might work for
> you, but for some reason I commented it out.  I don't remember what
> the reason was.  Maybe speed.
> '(defadvice undo (after org-undo-reveal activate)
>  "Make point and context visible after an undo command in Org-mode."
>  (and (org-mode-p) (org-reveal)))
> ;;(ad-unadvise 'undo)

Awesome, this is exactly what I was looking for!

> [1]  It is even more important when combined with what is IMO Emacs's
> greatest need for improvement, which is that you can undo, and undo an
> undo, and this is considered to be sufficient since you can get
> anywhere in the timeline in principle -- but many users, myself
> included, prefer a true redo command, both because undoing an undo
> does not let you do commands (such as copying) in the middle of an
> undo sequence without going the other direction, and because it feels
> more intuitive to tell emacs where in the timeline we want to go, and
> go forward or backward if we overshoot, thus making it possible to
> view the timeline the same way as we go backward and forward in any
> linear sequence.  (redo.el provides the functionality, but it corrupts
> the buffer.)  Of course, many are comfortable with the traditional
> undo-the-undo mechanism, so that should stay possible, but there are
> many who are not, and a redo mechanism would satisfy them.  It is
> possible to get more fancy with a tree.

The current undo system is very powerful as it doesn't lose history
(unless you hit a quota limit).  With undo-redo systems you usually can
lose history if you edit things in an old state.  Suddenly redo is not
available anymore.  You can only access the most recent branch in the
history tree.

In emacs this will not happen as you can reach all nodes in the buffer
history, but these states are not easily accessible, especially, if you
went back and forth some times.  I cannot track the list of states in my
mind or imagine the current structure of the undo tree, I can only go
step by step and look at the situation in the buffer and decide whether
this is what I wanted or not.

I recently stumbled upon an article which, I think, quiet nicely
summarized what one wants:

  http://e-texteditor.com/blog/2006/making-undo-usable

But it's not available for emacs ...

Cheers,
Martin