example.lisp

(defmacro code-generator-caller-1 (code-generator)
  `(quote ,(funcall code-generator)))

(defmacro code-generator-caller-2 (code-generator)
  `(quote ,(funcall (eval code-generator))))

(defmacro run-example (symbol)
  `(,symbol (lambda () 'hello)))

;; (run-example funcall)
;; yields:
;; HELLO
;;
;; (run-example code-generator-caller-2)
;; yields:
;; HELLO
;;
;; (run-example code-generator-caller-1)
;; yields:
;; The value
;;   (LAMBDA () 'HELLO)
;; is not of type
;;   (OR FUNCTION SYMBOL)
;;    [Condition of type TYPE-ERROR]