RE: vertical fido-mode

[Drew Adams]

> > Please don't add any bindings for C-n/C-p to any
> > standard minibuffer keymaps.  If you localize the
> > bindings, so they apply only to IDO, FIDO, Icomplete,
> > or whatever, e.g. `ido-completion-map', then OK -
> > I don't care about the bindings for those.
> 
> Noted. I think that is the plan, so you needn't worry much.
> But anyway, how often do you come across cases of
> multi-line completing-read?

Often.

For one thing, some common uses of completion in Icicles
allow for "multi-completion", which means providing
any of a number of possible subpatterns to match.

Those are separated by a separator string, whose default
value is "^G^J", that is, the two chars Control-G and
Control J.  Those chars are unlikely to be used in most
patterns.  (That string is inserted by hitting `C-M-j'.)
And the ^J is a newline char, of course.

For another thing, it's often the case that completion
candidates in Icicles are multiline.  Because you can
use various kinds of pattern matching, you can easily
match against multiple lines.  And you can cycle among
candidates (which fills the minibuffer with a candidate,
which can be multiline).

Whenever you have multiline text in the minibuffer, you
can want to edit that as a pattern to match, and C-n/C-p
are a good way to move among lines.

> At any rate, what's being proposed is a multi-line
> minibuffer, if I understand correctly.

I haven't been following this thread.  But if the content
of the minibuffer can/will be multiline, then I should
think that you would want to keep C-n/C-p with their
usual bindings.