[ˈsetˌkyü]
var—a symbol naming a variable other than a constant variable.
form—a form.
result—the primary value of the last form,
or nil
if no pairs were supplied.
Assigns values to variables.
(setq
var1 form1 var2 form2 ...)
is the simple variable assignment statement of Lisp.
First form1 is evaluated
and the result is stored in the variable var1, then form2
is evaluated and the result stored in var2, and so forth.
setq
may be used for assignment of both lexical
and dynamic variables.
If any var refers to a binding
made by symbol-macrolet
,
then that var is treated as if setf
(not setq
) had been used.
;; A simple use of SETQ to establish values for variables. (setq a 1 b 2 c 3) → 3 a → 1 b → 2 c → 3 ;; Use of SETQ to update values by sequential assignment. (setq a (1+ b) b (1+ a) c (+ a b)) → 7 a → 3 b → 4 c → 7 ;; This illustrates the use of SETQ on a symbol macro. (let ((x (list 10 20 30))) (symbol-macrolet ((y (car x)) (z (cadr x))) (setq y (1+ z) z (1+ y)) (list x y z))) → ((21 22 30) 21 22)
The primary value of each form is assigned to the corresponding var.