Subject: 28.2; Feature request; facility for dispatch type major mode

From: Ikumi Keita <[email-masked]>
Date: Wed, 01 Feb 2023 21:28:07 +0900

I'd like to discuss dispatch functions or "superficial" major modes.
AUCTeX has the following major mode functions:
context-en-mode, context-nl-mode, japanese-latex-mode, japanese-plain-tex-mode
They only do language-specific set-ups and turn into context-mode,
latex-mode or plain-tex-mode eventually. In some aspects, they are
similar with dispatch functions `tex--guess-mode' and `TeX-tex-mode'
(AUCTeX) which guess a proper major mode and call it:
- They can be specified as `mode' tag of file local variable and entry
  of `auto-mode-alist'.
- They never hold their own `major-mode' value.
- When called, they eventually turn into another proper major mode.
For these reasons, they can be called "superficial" major modes.

Note that it isn't enough to define them like
(define-derived-mode japanese-latex-mode latex-mode "LaTeX"
  ...
  (setq major-mode 'latex-mode)
  ...)
because it doesn't respond to directory local variable entry of the form
((japanese-latex-mode
  ...))
in that case.

So I hope emacs to have facility to handle such superficial major modes
in a clean way.

Regards,
Ikumi Keita
#StandWithUkraine #StopWarInUkraine

In GNU Emacs 28.2 (build 1, x86_64-unknown-freebsd13.1, GTK+ Version 3.24.33, cairo version 1.17.4)
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