write two common kinds of loops.
@defmac dolist (var list [result]) body@dots{}
-@tindex dolist
This construct executes @var{body} once for each element of
@var{list}, binding the variable @var{var} locally to hold the current
element. Then it returns the value of evaluating @var{result}, or
@end defmac
@defmac dotimes (var count [result]) body@dots{}
-@tindex dotimes
This construct executes @var{body} once for each integer from 0
(inclusive) to @var{count} (exclusive), binding the variable @var{var}
to the integer for the current iteration. Then it returns the value