Richard Stallman <rms@gnu.org> writes:

> We could add a facility to define a &rest function to specify
> another function to handle the one-arg case.

It's slightly off-topic, but I also often miss a function to do function
composition in Emacs-Lisp.  What about adding a `compose' function,
similar to
https://common-lisp.net/project/cl-utilities/doc/compose.html?  I'd be
glad to add it.

Nico