How to overcome the lack of local variable for emacs lisp closure

Question

I\'m now studying Emacs Lisp from the reference manual and Common Lisp from a LISP Book.

from the Common Lisp book

>> (setf power-of-two
     (let          


        

Answer 1

another solution using Emacs' unintern symbol:

ELISP> (setf power-of-two
         (let ((p (make-symbol "previous-power-of-two")))
           (set p 1) (list 'lambda '()
           (list 'setf p
             (list '* p 2)))))

ELISP> (funcall power-of-two)
2
ELISP> (funcall power-of-two)
4
ELISP> (funcall power-of-two)
8