gistfile1.cl

(require :fare-matcher)

;; Clojure or ML's function syntax style defun

(defmacro defunction (name &body body)
  (flet ((match-clause (clause)
	   (cons `(list ,@(car clause)) (cdr clause))))
    (let ((args (gensym)))
      `(defun ,name (&rest ,args)
	 (fare-matcher:ematch ,args
	 ,@(mapcar #'match-clause body))))))

;; examples

(defunction f
  ((:ping) :pong)
  ((:echo x) x))

(f :ping) ; ==> :pong
(f :echo "hi") ; ==> "hi"
(f 1 2 3) ; ==> raise error