Macro to make simple classes

class-macro.lisp

(defmacro define-info-class (name &rest slots)
  (labels ((make-slot (name slot)
             (read-from-string
              (concatenate 'string (string name) "-" (string slot)))))
    (flet ((make-slot-list-item (slot)
             (list slot :accessor (make-slot name slot)))
           (make-name (name)
             (read-from-string
              (concatenate 'string (string name) "-info"))))      
      (let* ((class-name (make-name name))
             (class-slots (mapcar #'make-slot-list-item slots)))
        `(defclass ,class-name ()
           ,class-slots)))))

(defmacro populate-info-object (name &rest slots)
  (flet ((get-setter (slot)
           (let ((expression (read-from-string (concatenate 'string "((" (string name) "-" (string slot) " " (string name) ") " (string slot) ")"))))
             (car `((setf ,(car expression) ,(cadr expression)))))))
    (let ((object-name  (read-from-string (string name)))
          (setters (mapcar #'get-setter slots)))
      `(progn
         ,@setters
         ,object-name))))

;; example usage
(define-info-class date second minute hour day month year day-of-the-week daylight-p zone) 

(defmethod get-parsed-date ((date date-info) universal-time)
  (multiple-value-bind
        (second minute hour day month year day-of-the-week daylight-p zone)
      (decode-universal-time universal-time)
    (populate-info-object date second minute hour day month year day-of-the-week daylight-p zone)))