map functionsThe dolist macro is
faster than the mapc function,
as it expands to while with inlined BODY
with no lamda indirection:
(macroexpand '(dolist (x '(10 20 30)) (* x 2)))
(let ((tail '(10 20 30))) (while tail (let ((x (car tail))) (* x 2) (setq tail (cdr tail)))))