On Thu, Dec 29, 2022 at 12:18:01PM +0300, Jean Louis wrote:
> Thanks Thomas, after following your corrections:
> 
> (setq my-list '()) ➜ nil
> (benchmark 10000000 '(setq my-list (cons "Word" my-list))) ➜ "Elapsed time: 5.943843s (4.111302s in 3 GCs)"
> 
> It works!
> 
> > Read benchmark's doc string carefully :-)
> 
> My misunderstanding is with FORM and BODY, when I read FORM, I
> understand it is same as BODY. Now I see the difference.
> 
> I have found reference in Emacs Lisp manual, but I cannot find
> reference that FORM as argument means quoted sexp, if you have that
> reference, let me know

It's a bit subtle, since the point is rather the intention
than the data type itself (the result of an evaluation is
itself a form after all -- that's the magic of Lisp).

The next I came to it (I searched Elisp's manual with `i'
then `form' is "10.1 Introduction to Evaluation":

     A Lisp object that is intended for evaluation is
   called a “form” or “expression”(1).  The fact that
   forms are data objects and not merely text is one 
   of the fundamental differences between Lisp-like
   languages and typical programming languages.  Any
   object can be evaluated [...]

Worth reading :)

Cheers
-- 
t