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tree—a tree.
new-tree—a tree.
Creates a copy of a tree of conses.
If tree is not a cons, it is returned;
otherwise, the result is a new cons of the results of calling copy-tree
on the car and cdr of tree.
In other words, all conses in the tree represented by tree
are copied recursively, stopping only when non-conses are encountered.
copy-tree
does not preserve circularities and the sharing of substructure.
(setq object (list (cons 1 "one") (cons 2 (list 'a 'b 'c)))) → ((1 . "one") (2 A B C)) (setq object-too object) → ((1 . "one") (2 A B C)) (setq copy-as-list (copy-list object)) (setq copy-as-alist (copy-alist object)) (setq copy-as-tree (copy-tree object)) (eq object object-too) → true (eq copy-as-tree object) → false (eql copy-as-tree object) → false (equal copy-as-tree object) → true (setf (first (cdr (second object))) "a" (car (second object)) "two" (car object) '(one . 1)) → (ONE . 1) object → ((ONE . 1) ("two" "a" B C)) object-too → ((ONE . 1) ("two" "a" B C)) copy-as-list → ((1 . "one") ("two" "a" B C)) copy-as-alist → ((1 . "one") (2 "a" B C)) copy-as-tree → ((1 . "one") (2 A B C))