Hi! I'm the author of icomplete-vertical. I'd be very happy to see the
icomplete-vertical functionality included in Emacs, and Ergus is completely
correct:
But as I see the code in icomplete-vertical-mode; it relies in a hook
(icomplete-vertical-minibuffer-setup) and an advice
(icomplete-vertical-format-completions) which in principle we don't need with a
very simple modification of icomplete-completions and
icomplete-minibuffer-setup. If icomplete-completions produces the formated
output it will be more efficient and clean than adding an advice or do a
reformat.
That's exactly what should be done: not include the icomplete-vertical package
as is, but instead make small modifications of the existing icomplete package
to incorporate the changes.
There are also some customizable options that for a simple working vertical
mode we shouldn't need (like icomplete-vertical-separator-alist or a face
icomplete-vertical-separator) unless we want to add them now.
Again, Ergus is completely right! Those, with the benefit of hindsight, are
over-engineered and shouldn't be included in Emacs. Heck, they shouldn't even
be in icomplete-vertical. (I've learned that lesson and although I subsequently
wrote a few more completion UIs, I didn't include options analogous to those.)
--
Omar Antol�n Camarena