Re: Questions about isearch

[Eli Zaretskii <eliz@gnu.org>]

> From: Richard Stallman <rms@gnu.org>
> CC: per@starback.se, emacs-devel@gnu.org, sb@dod.no
> Date: Fri, 27 Nov 2015 01:38:32 -0500
> 
> You seem to be trying to design an ultimate, ideal current language
> facility.

Yes.

> We might want to get there eventually, but I think we should start
> with something simple.

IMO, the initial implementation could have only partial support for
multiple languages, but the design should allow for extending that all
the way towards the eventual goal, which cannot possibly be a single
language per buffer, not in Emacs 2X.

> After all, most buffers have only one language in them.

Not in my experience: buffers that combine English and Hebrew are
something I see every day.  The simplest example is email: the headers
are in English, while the body is in a mix of Hebrew and Latin
(usually English) words.

> Having a selectable language for the whole buffer is going to be
> better than the current situation where you can't select it.

I agree.

> If you have a table in Turkish in the middle of a English document,
> and you want to sort the table, you can switch the buffer to Turkish,
> sort, and switch back to English.

Language-specific processing is not limited to sorting contiguous
regions in the buffer.  This discussion started from Isearch, so the
example which underlines the issues is searching for a string with
character-folding enabled -- this should automatically apply
language-specific rules when it hits a possible match in the Turkish
portion, then switch back to English when the match is in the English
part.  Same with spelling -- you'd want flyspell to use the right
language in each portion, without the need to restart the speller
program with another dictionary.