Re: Customize and autoloaded libraries

[Richard Stallman]

    1. Keep user options and variables set by Lisp packages separate.

In general, we try to do this--but there have to be exceptions.  If we
make hooks customizable, they will certainly still be set by Lisp
code.

    2. Invent a `defhook' declaration for hooks, which is like defcustom
       but allows merging the same way as add-hook.  I wanted to do that
       originally, but couldn't come up with a good design.

I think this general idea is the best solution.  I am not sure we
need to have a separate `defhook' function though.

Instead of merging, maybe we could arrange for add-to-hook to cause
the autoloading and processing of the defcustom, first thing.  That
could avoid the need for any actual merging of values.  Ok?

    3. Write a general merge algorithm for all options.  This also solves
       the problem of options with large or fragile (over versions)
       initial values, like "load-path".

That would be an elegant feature, but it we don't need it, and it is
likely to be a lot of work--which would be taken away from doing
something else.  So we should not do this.