Added a newer version of the code. Cleaned up the defstruct definition.

mydefstruct.lisp

@@ -0,0 +1,35 @@
+
+(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)))