Vim itself is very "sequency" in how ex commands can be entered. For example all of the following ex commands quit: q, qu, qui, quit. You could imagine vim using a regex like \vq% [uit] to check them.

When searching by pressing the forward slash / and entering some characters, then pressing tab for completion, Vim displays a couple of regex errors and also the pum is not placed below the first ...

I'm one program away from using Linux full-time on my laptop - I need a replacement for Home Site (a web page editor). I can fumble around in both vim and emacs well enough to do everything I want ...