(defun constructor-name (sym)
  (intern (concatenate 'string "MAKE-" (string sym))))

(defun accessor-name (name sym)
  (intern (concatenate 'string (string name) "-" (string sym))))

(defun setter-name (name sym)
  (intern (concatenate 'string "SET-" (string name) "-" (string sym))))

(defun constructor (name slots)
  `(defun ,(constructor-name name) ,slots
     (list ,@slots)))
(defun accessors (name slots)
  (loop for slot in slots
	for i upfrom 0 collect
	`(defun ,(accessor-name name slot) (obj)
	   (nth ,i obj))))
(defun setters (name slots)
  (loop for slot in slots
	for i upfrom 0 collect
	`(defun ,(setter-name name slot) (obj val)
	   (setf (nth ,i obj) val))))
(defun setfers (name slots)
  (loop for slot in slots collect
	`(defsetf ,(accessor-name name slot)
	     ,(setter-name name slot))))


(defmacro mydefstruct (name &rest slots)
  `(progn
     ,(constructor name slots)
     ,@ (accessors name slots)
     ,@ (setters name slots)
     ,@ (setfers name slots)))