Re: find-file-hook as illustration of Custom problems

[Luc Teirlinck]

>From my previous reply:

      Any other elements could be invisible and untouchable; or they
      might be displayed in a separate way as "program-added hooks"
      and untouchable through the usual Custom features.

   I believe the latter.  The user should know that there are other,
   untouchable things in the list.

Actually, the situation is more complex, certainly for non-hook atoms
(and I would guess probably also for many hooks).  Code puts things in
variables like completion-ignored-extensions, debug-ignored-errors,
file-coding-system-alist, help-event-list,
minibuffer-prompt-properties, mode-line-format,
same-window-buffer-names, same-window-regexps, and many others, that
the user definitely might want to override.  The same could be true
for many hooks.  So it looks like we should also give the user veto
power over code and implement `remove-hook' and `delete' functionality
through Custom, adding to the complexity.

Sincerely,

Luc.