Re: windows-1251 language environment

[Kenichi Handa <handa@m17n.org>]

In article <E1A9Usz-0006PI-SL@fencepost.gnu.org>, Richard Stallman <rms@gnu.org> writes:
>     This issue is not that urgent, but I'm sure we must do
>     something to allow users to customize a language environment

> Why aren't the existing facilities enough for that?

Existing facility is to write Emacs Lisp code in .emacs
which is not for normal users.

>     and to avoid the explosion of numbers of language
>     environments.

> Asking users to define their own language environments, instead of
> defining them in Emacs, can help with that.  I don't see how
> inheritance would help.

Currently, a user must define his own language environment
from scratch.  But, usually what they want is to prefer the
diffent default input method, prefer the different coding
system than the existing one.  In such a case, what he have
to do is, currently, see source code of
lisp/language/XXX.el, copy

   (set-language-info-alist ....)

into his .emacs, and modify some part of it.  If we allow
inheritance, he can do something like:

(define-language-environment Japanese-utf-8
  '((inherit . "Japanese")
    (coding-sytem utf-8 iso-2022-jp euc-jp)))

>     My intention is to have something like "new" under this menu:
> 	    <menu-bar> <options> <mule> <set-language-environment>
>     When "new" is selected, Emacs put a user in a buffer in
>     which he can create his own language environment
>     interactively.  Typing C-c C-c should ask if he want to use
>     that environment in the future session.

> That seems like a good feature.  It could be implemented with
> or without define-derived-language.

Yes, but in the above buffer, it seems that "inherit" and
"copy" button is helpful.  For instance, clicking "inherit"
and selecting LANG will show the default values for each
slots.  Clicking "copy" and selecting LANG fills all slots
by values of LANG.

I don't intend to have the actual functions
define-derived-language.  I think just adding a new key
"inherit" in language-info-alist is enough.

---
Ken'ichi HANDA
handa@m17n.org