acons (Function)

Syntax:

Arguments and Values:

key—an object.

datum—an object.

alist—an association list.

new-alist—an association list.

Description:

Creates a fresh cons, the cdr of which is alist and the car of which is another fresh cons, the car of which is key and the cdr of which is datum.

Examples:

 (setq alist '()) → NIL
 (acons 1 "one" alist) → ((1 . "one"))
 alist → NIL
 (setq alist (acons 1 "one" (acons 2 "two" alist))) → ((1 . "one") (2 . "two"))
 (assoc 1 alist) → (1 . "one")
 (setq alist (acons 1 "uno" alist)) → ((1 . "uno") (1 . "one") (2 . "two"))
 (assoc 1 alist) → (1 . "uno")

See Also:

assoc, pairlis

Notes:

(acons key datum alist) ≡ (cons (cons key datum) alist)