Commit 369fba5f authored by Richard M. Stallman's avatar Richard M. Stallman
Browse files

(last): Accept optional second argument.

parent 59966fb6
......@@ -79,12 +79,20 @@ BODY should be a list of lisp expressions."
"Return the cdr of the cdr of X."
(cdr (cdr x)))
(defun last (x)
"Return the last element of the list X.
If X is nil, return nil."
(while (cdr x)
(setq x (cdr x)))
x)
(defun last (x &optional n)
"Return the last link of the list X. Its car is the last element.
If X is nil, return nil.
If N is non-nil, return the Nth-to-last link of X.
If N is bigger than the length of X, return X."
(if n
(let ((m 0) (p x))
(while (consp p)
(setq m (1+ m) p (cdr p)))
(if (<= n 0) p
(if (< n m) (nthcdr (- m n) x) x)))
(while (cdr x)
(setq x (cdr x)))
x))
;;;; Keymap support.
......
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