gistfile1.scm

(define (get-object-documentation object)
  (cond
   ((instance? object <function>)
    (slot-ref object 'documentation))
   ((instance? object <form>)
    (slot-ref object 'documentation))
   ((instance? object <macro>)
    (get-object-documentation (slot-ref object 'procedure)))
   (else "Unknown object")))