Re: define-derived-mode

[Luc Teirlinck]

Richard Stallman wrote:

   I don't follow the logic of this argument.  Whatever group is right
   for the move variable, isn't that right for the hook variable too?

I believe that we are misunderstanding each other, but since I changed
my mind on the issue in the meantime, this has become irrelevant.

   However, I am not sure we want defcustoms for *any* mode hooks.  How
   often would a user want to customize one with defcustom?  It seems to
   me that defcustoms for mode hooks are mostly useless clutter.

   What argument is there that they are useful and worth their cost?

When I originally proposed this (I no longer am), I was worrying about
consistency with `define-{minor,generic}-mode'.  I already pointed out
in my original message that I was less than enthused about these two
functions spewing out all these automatic defcustoms.

Customizing mode hooks through Custom is only convenient if an
:options keyword is used.  (Currently, customizing hooks through
Custom is not advisable to begin with because of several bugs we
discussed before.  We plan to fix these in Emacs 23 or 24.)

If I understood correctly, define-generic-mode only started
constructing automatic defcustoms recently, which was an incompatible
change.   In that case, it could easily be reversed, which would make
the two major mode defining functions consistent in this respect.

For define-minor-mode, the situation is more complex.  It already
defined defcustoms in 21.3.  So here, removing them would be an
incompatible change.  It is possible that some users already
customized these hooks through Custom.

Sincerely,

Luc.