;Chapter 4, Bryan Test 2, Page 69-70
;Structure to help test-structure.
(defstruct (callrecord2 (:print-function print-callrecord2));creates a structure with 3 members, and will call print-callrecord2 when tostring is called
  (number nil)
  (durration 0)
  (status "just beginning"))

(defun print-callrecord2 (stream obj depth) ;takes the stream, object, and depth, and calls format to print.
  (format stream "The call to ~A lasted for ~A minute(s), and is now ~A." (callrecord2-number obj) (callrecord2-durration obj) (callrecord2-status obj)))

(deftest test-structure-2 ()
  (let ((num 13)
        (mycall (make-callrecord2)) ;create empty instance
        (thatcall (make-callrecord2)) ;create another empty instance
        (yourcall (make-callrecord2 :number "+13302940684" :status "complete" :durration 10.5)))  ; create populated instance
    (setf mycall (copy-callrecord2 yourcall)) ;copies the data member wise from yourcall to mycall
    (setf (callrecord2-number thatcall) "+13046585755") ;sets number in thatcall to ...

    (check
      (equal (callrecord2-number thatcall) "+13046585755")  ;Checks the value stored in thatcall->number two lines above
      (equal (print-callrecord2 nil mycall 0) "The call to +13302940684 lasted for 10.5 minute(s), and is now complete.");  tests the print function
      (not (callrecord2-p num)) ;checks to make sure that the predicate works.
      (callrecord2-p mycall)  ;same as above
      (typep mycall 'callrecord2) ;uses typep to show that callrecord2 is now an official type
      (equal (callrecord2-status thatcall) "just beginning"); checks the status of a call.
      (not (equal mycall yourcall))))) ;shows that two instances of a class are not equal even though the values are the same.