using finalizers

[Tomas Hlavaty]

Hi,

I am trying to understand finalizers in Emacs Lisp but I am unable to
triger it.

Here is an example (with lexical-binding):

(defun finito ()
  (let ((x '(a b c)))
    (letrec ((more (make-finalizer close))
             (close (lambda ()
                      (print "close-resource")
                      (setq more nil))))
      (lambda ()
        (when more
          (pop x))))))
(setq foo (finito))
(equal '(a b c nil nil) (mapcar (lambda (x) (funcall foo)) '(1 2 3 4 5)))
(setq foo nil)
(garbage-collect)

After garbage collection, I would expect to see close-resource text in
the *Messages* buffer but there is none.

The interface is different from Common Lisp, where make-finalizer
usually expects object and thunk, not thunk only but I guess the problem
lies somewhere else.

What is the expected example usage of finalizers in Emacs Lisp?
How can I verify, that my finalizer works?

Thanks in advance

Tomas