common-lisp Basic loops dolist
Example
dolist is a looping macro created to easily loop through the lists. One of the simplest uses would be:
CL-USER> (dolist (item '(a b c d))
(print item))
A
B
C
D
NIL ; returned value is NIL
Note that since we did not provide return value, NIL is returned (and A,B,C,D are printed to *standard-output*).
dolist can also return values:
;;This may not be the most readable summing function.
(defun sum-list (list)
(let ((sum 0))
(dolist (var list sum)
(incf sum var))))
CL-USER> (sum-list (list 2 3 4))
9
