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

[Kaushal]

Isearch has a couple of toggles like case-fold, isearch-invisible and now char-fold.

After updating, I noticed that the prompt for the regular `C-s` is now "Char-fold Isearch: ".

Should that "Char-fold" prefix be there? If so, we should also display what other isearch options are in effect (case-fold, etc).

Suggestion: 

- The prefix be kept the same as before ("Isearch: ") for brevity.

- The moment a user starts Isearch (or when user calls a command during Isearch using some binding), the effective isearch properties are flashed in the echo area. That "flashing" would look just as the case-sensitivity state is flashed on hitting `M-c` during isearch. An example of such flashed message could be

    [Case-fold: on Char-fold: on  Search-invisible: off]

- If we don't want to flash that message, the message can be displayed and be allowed to stay there till user starts/resumes typing in the minibuffer.

Thoughts?

On Wed, Jun 24, 2015 at 9:56 PM Artur Malabarba <address@hidden> wrote:

> So the most important remaining problem is how to combine char-folding
> with ‘isearch-lax-whitespace’ and ‘search-whitespace-regexp’.
> It seems this will require duplicating some code between these two.

I took a shot at this on the last commit. `character-fold-to-regexp'
now takes a second argument (lax), when this is non-nil it appends a +
to the regexp generated from whitespace characters.
It doesn't take `search-whitespace-regexp' into consideration, but I
don't know if that would even make sense given that a character-folded
space is even more general (matches more characters) than what's
specified by `search-whitespace-regexp'.