Simple Partial Evaluator...
(progn ; (fn args)
(setq args (mapcar #'(lambda (x)
(mix x env)) ; mix the args
(cdr code)))
(if (and (every #'constantp args) ; if all constant args
(not (member fn '(print ; and no
prin1 princ error ; compile-time
format)))) ; side-effects
(kwote (eval (cons fn args))) ; eval it now
(if (and (some #'constantp args); if some constant
(fndef fn)) ; & symbolic fn
(fnmix fn args) ; unfold the fn
(fnopt (cons fn args))))))) ; optimize result
(cons 'bad-code code)) ) ) ))