RE: ASCII-folded search [was: Re: Upcoming loss of usability ...]

[Drew Adams]

> I don't know how you're planning on solving doing this,  but I was
> going to suggest that isearch could just take over the mode-line
> while in effect, that would it give it a lot of space to verbosely
> display the searching options (and maybe even list the key binds
> for each) and each option could be a button that toggles itself.

FWIW - I have long done this in Isearch+.

But without "tak[ing] over the mode line" and without using "a lot
of space to verbosely display the searching options" or "list[ing]
the key binds for each" or adding buttons.

What isearch+.el does is update only the `Isearch' lighter to
show case sensitivity and search wraparound, as well as word,
regexp-vs-literal, and multi-buffer search.

Case sensitivity is shown just by the text of the lighter:

 Isearch - case-sensitive
 ISEARCH - case-insensitive (case folding)

Wraparound is also shown in the lighter, by using a different face.

The other states are each indicated by a different face on the
relevant part of the prompt, as they are orthogonal to case
sensitivity.

For example, a multi-buffer regexp search uses prompt

 Regexp multi I-search:

with `Regexp' in face `isearchp-regexp' and `multi' in face
`isearchp-multi'.  When wrapped it uses prompt

 Wrapped regexp multi I-search:

with faces as above plus `Wrapped' in face `isearchp-wrapped'.

(http://www.emacswiki.org/emacs/IsearchPlus)