(eval-when (:compile-toplevel)) in (eval-when (:compile-toplevel))

test.lisp

#|
Some experiments to understand the example of CLHS eval-when explanations.
( http://clhs.lisp.se/Body/s_eval_w.htm#eval-when )

;;; #4: This always does nothing. It simply returns NIL.
 (eval-when (:compile-toplevel)
   (eval-when (:compile-toplevel)
     (print 'foo4)))
|#


(in-package :cl-user)

(eval-when (:compile-toplevel)          ; Action is 'Evaluate'
  (print "compile-toplevel")            ; Printed only on COMPILE-FILE.
  (eval-when (:execute)
    (print "execute in compile-toplevel")) ; Printed only on COMPILE-FILE.

  ;; The forms below are never executed.
  ;; Is it because they are *NOT* top level forms here?
  (eval-when (:compile-toplevel)
    (print "compile-toplevel in compile-toplevel")) ; never printed.
  (eval-when (:compile-toplevel :load-toplevel)
    (print "compile-toplevel load-toplevel in compile-toplevel"))) ; never printed.



(eval-when (:compile-toplevel :load-toplevel) ; Action is 'Process compile-time-too'
  (terpri)
  (print "compile-toplevel load-toplevel") ; Printed on COMPILE-FILE and LOAD the fasl.
  (eval-when (:compile-toplevel :load-toplevel)
    (print "compile-toplevel load-toplevel in compile-toplevel load-toplevel")) ; Printed on COMPILE-FILE and LOAD the fasl.
  (eval-when (:compile-toplevel)
    (print "compile-toplevel in compile-toplevel load-toplevel")) ; Printed only on COMPILE-FILE.
  (eval-when (:load-toplevel)
    (print "load-toplevel in compile-toplevel load-toplevel")) ; Printed only on LOAD the fasl.

  (eval-when (:execute)                 ; Action is 'Evaluate'
    (print "execute in compile-toplevel load-toplevel") ; Printed only on COMPILE-FILE.
    (eval-when (:compile-toplevel :load-toplevel)
      (print "compile-toplevel load-toplevel in execute in compile-toplevel load-toplevel")) ; never printed
    ))


;;; (load "test.lisp") does not execute any forms above.