deferred-action

[Juanma Barranquero <lekktu@gmail.com>]

What are the variables deferred-action-list and
deferred-action-function used for?

Their API is a bit surprising: there's a list of things to do, and a
function to do things (so, a sort of a poor man's hook) with
absolutely no explanation (nor documentation on the Elisp manual) of
how it is intended to be used, how to manage conflicts supposing that
different pieces of code want to use it, etc.

The only reference to them on the Emacs sources is in
emacs-lisp/ert-x.el, and it's really just aping the Emacs
command-loop.

And the only other reference I find is in anything.el (in the Emacs
wiki), where they are basically used as a sort of post-command hook.

I think Roland McGrath asked basically this same question back in 1994
(http://www.maths.tcd.ie/local/JUNK/cyclic/mailing-lists/arcana/0022.html),
so perhaps it is time to document these variables or deprecate them.

    Juanma