LispForum

Thank you for your answer and pointers to defsetf and define-setf-expander. I will study it.

Hello Lispers! It is usually said that (pop stack) is equivalent of (prog1 (first stack) (setf stack (rest stack))) or (let ((elt (first stack))) (setf stack (rest stack)) elt). I don't understand why the following function doesn't work as an equivalent of built-in pop: (defun my-pop (lst) (let ((x ...