CLCS
Function

copy-alist

copy-alist alistnew-alist

Arguments and Values

alistan association list.
new-alistan association list.

Description

copy-alist returns a copy of alist.

The list structure of alist is copied, and the elements of alist which are conses are also copied (as conses only). Any other objects which are referred to, whether directly or indirectly, by the alist continue to be shared.

Examples

(defparameter *alist* (acons 1 "one" (acons 2 "two" '())))
*alist* ⇒  ((1 . "one") (2 . "two"))
(defparameter *list-copy* (copy-list *alist*))
*list-copy* ⇒  ((1 . "one") (2 . "two"))
(defparameter *alist-copy* (copy-alist *alist*))
*alist-copy* ⇒  ((1 . "one") (2 . "two"))
(setf (cdr (assoc 2 *alist-copy*)) "deux") ⇒  "deux"
*alist-copy* ⇒  ((1 . "one") (2 . "deux"))
*alist* ⇒  ((1 . "one") (2 . "two"))
(setf (cdr (assoc 1 *list-copy*)) "uno") ⇒  "uno"
*list-copy* ⇒  ((1 . "uno") (2 . "two"))
*alist* ⇒  ((1 . "uno") (2 . "two"))

See Also

copy-list