Re: Is this a bug of Emacs-Lisp?

[Luc Teirlinck]

Zhang Wei wrote:

   Modify the return value of dummy changed it's defination. Is this
   a bug of Elisp? If it's not. How does this happen?

>From my previous reply:

    If a function returns a quoted cons, then after you change the cdr of
    the cons, it still returns that (now changed) cons.

More precisely: you change the actual cons stored in the function cell
of the symbol `dummy'.  The function returns that stored cons each
time it is called.  To make it return a new cons each time, make it
return (cons 1 2).

Sincerely,

Luc.