Re: Questions about isearch

[Eli Zaretskii <eliz@gnu.org>]

> Date: Wed, 25 Nov 2015 21:49:58 +0000
> From: Artur Malabarba <bruce.connor.am@gmail.com>
> Cc: emacs-devel <emacs-devel@gnu.org>
> 
> > > > 2. It also doesn't match ä (a single character) with ä (2 characters,
> > > > which Emacs correctly composes into 1 grapheme cluster). Should it?
> > >
> > > Possibly. Since they look the same, might make things easier on users. But
> I
> > > wouldn't know as I've never seen the second version used anywhere.
> >
> > Once again, the decomposition attribute says we should match them:
> >
> > (get-char-code-property ?ä 'decomposition)
> > => (97 776)
> >
> > and the second character in ä is U+0308 = 776. Doesn't that say we
> > should have matched them?
> 
> That's different. Currently we use the decomposition attribute to decide that
> "a" should match ä. Our approach so far has been that searching for the "easy
> to type" characters should match the "hard to type" characters, but searching
> for the "hard to type" characters will only match the character itself. So
> right now it is working as intended. 
> 
> We can (and I think we should) extend that last case so that searching for the
> "hard to type" characters will only match the character itself or its exact
> decomposition. 

The first part (matching only itself) already works, AFAICS.  If the
latter doesn't require too deep changes, I think we should do that for
Emacs 25.1, because it would be confusing not to have that.

Thanks.