[ELPA] Brief v5.90: neighboring window merge on deletion

[路客]

Hi all,

In case you are interested.  I've just released the Brief editor mode
v5.90 targeting the feature `merge neighboring window on deletion'.
This functionality merges two aligned adjacent windows regardless of how
Emacs currently splits the frame.  It meaning that even if two aligned
neighboring windows in the same frame belong to different parent
(internal) windows, they can almost always be merged by reconstructing
the window tree properly.

This is probably not a big deal but for me this task had been postponed
for over 20 years due to not finding time to implement them until
recently.  It took me sometime early this year to figure out an
efficient algorithm.  It reconstructs window subtree reorganizing
vertical/horizontal spliter lines to achieve the desired window layout.
However, due to the restriction on how Emacs split windows there are
still layouts that can't be displayed by Emacs.  A typical such window
layout is:
 ______
|____| |
| |__|_|
|_|____|

Any such structure within any sub-window of a frame cannot be displayed,
as far as I know (let me know if any of you know a simple way to do so).
But for regular daily use we don't really need this kind of window
layout so it won't be supported unless a simple approach is found.

Notice that the atomic window is not yet properly handled and is
on-going, if you find any other window attribute not taken care of
properly, please be sure to let me know.

Thanks!

-- 
Best regards,
Luke Lee