🚀 go-pugleaf

   Jeffrey> (defclass test-class ()
   Jeffrey> 	((slot-1	:initarg :slot-1
   Jeffrey> 		:initform 1
   Jeffrey> 		:accessor slot-1)
   Jeffrey> 	(slot-2	:initarg :slot-2
   Jeffrey> 		:initform ?????      ; <- The question
   Jeffrey> 		:accessor slot-2)))

   Jeffrey> The problem is that I need for slot-2 to default to the same value as
   Jeffrey> slot-1 if the user does not specify it in the constructor.


I believe the following will do what you want provided that you are
willing to call with :slot-2 first when both initargs are used (see
CLtL2 28.1.9.4. first paragraph after the last bullet):

(defclass test-class ()
  ((slot-1 :initarg :slot-1
           :initform 1
           :accessor slot-1)
   (slot-2 :initarg :slot-1 :initarg :slot-2 
           :accessor slot-2)))


Required call order for non-defaulting case:

(make-instance 'test-clas :slot-2 5 :slot-1 3 )


I hope this helps.

                                   Eric Peterson (speaking for myself)
                                   Systems Research and Applications
                                   2000 15th Street North
                                   Arlington, VA 22201
                                   USA
                                   peterson@sra.com
                                   (703) 558-7644
                                   Fax:  (703) 558-4723