Re: Changes for emacs 28

[Juri Linkov]

>>> A global mode like undo-redo-mode, like suggested by Ergus, would avoid
>>> both of these problems. We'd only need to find a key for 'undo-redo'.
>>>
>>> Perhaps, 'M-_' and 'C-?'? That's what undo-tree uses by default.
>> I use C-/ for undo so C-? in my keyboard is C-S-/ so it is perfect. But
>> for people using C-_ (C-S--) maybe M-_ (M-S--) will make more
>> sense (BTW: in Spanish keyboard it does).
>
> Right, and I did mean using both key sequences.
>
> Since default Emacs binds 'undo' to both 'C-_' and 'C-/', it would make
> sense to add a corresponding 'redo' binding to each using nearby keys.

What about adding a transient mode activated by a key sequence.
When the mode is active, it will enable arrow keys to navigate the
undo history in both directions: <left> to undo, and <right> to redo.
This is similar to 'indent-rigidly' bound to 'C-x TAB':

  If called interactively with no prefix argument, activate a
  transient mode in which the indentation can be adjusted interactively
  by typing <left>, <right>, <S-left>, or <S-right>.
  Typing any other key deactivates the transient mode.