(defun atoms (w)
(loop for a in w
if (atom a) collect a
else append (atoms a)))
> (atoms '((a b) c nil (d (e f g))))
(A B C NIL D E F G)(defun atoms (w)
(typecase w (atom `(,w))
(t (mapcan #'atoms w))))
> (atoms '((a b) c nil (d (e f g))))
(A B C NIL D E F G)(defun atoms (w)
(if (atom w) `(,w) (mapcan #'atoms w)))
> (atoms '((a b) c nil (d (e f g))))
(A B C NIL D E F G)