elisplisp.el

;; emacs-lisp-lisp (ell) demmo

(ell
  ;; define a global var mapcar that is the typical mapcar function
  (setq mapcar
        (lambda (fn data)
          (print 'hi)
          (if (null data)
              nil
            (cons (fn (car data))
                  (mapcar fn (cdr data)))))))

(ell 
  (let ((plus3 (lambda (x) (+ x 3))))
    (if (= (plus3 10) 13)
        (elldo
         (print "it's working!")
         (print (mapcar plus3 (list 1 2 3))) ;; ell mapcar, will print 'hi 4 times before printing result
         (let ((mapcar '(native . mapcar)))
           (mapcar plus3 (list 4 5 6))))))) ;; emacs lisp mapcar

;; output

"it's working!"

hi

hi

hi

hi

(4 5 6)
(7 8 9)