RosettaCodeData/Task/Function-definition/Common-Lisp/function-definition-2.lisp
2023-07-01 13:44:08 -04:00

4 lines
190 B
Common Lisp

(define-compiler-macro multiply (&whole expr a b)
(if (and (constantp a) (constantp b))
(* (eval a) (eval b))
expr)) ;; no macro recursion if we just return expr; the job is done!