Re: BIKESHED: completion faces

[Stefan Monnier]

> I've tried to implement my idea, but somehow the added highlighting gets
> eaten before the buffer is displayed. But the attached patch should 
> illustrate it anyway.

Regardless of how we implement this, the question remains: do we want to
highlight the common-part of the prefix/basic completion differently
from the other cases?


        Stefan


PS: I think the approach used in your patch will lead to undesirable
behavior when some matches (but not all) have all chars before
first-diff highlighted with common-part.  E.g.

    src/emacs -Q --eval '(setq completion-styles (quote (partial-completion)))'
    M-x re-b ?

where `re-builder` would be highlighted with a "trivial common part"
whereas `rename-buffer` would be highlighted differently.

You might consider it as a feature, of course.  But if not, then we'd
have to first look at all the completions to make sure they all have
a "trivial common part".