Function LAST

Syntax:

last list &optional n => tail

Arguments and Values:

list---a list, which might be a dotted list but must not be a circular list.

n---a non-negative integer. The default is 1.

tail---an object.

Description:

last returns the last n conses (not the last n elements) of list). If list is (), last returns ().

If n is zero, the atom that terminates list is returned. If n is greater than or equal to the number of cons cells in list, the result is list.

Examples:

``` (last nil) =>  NIL
(last '(1 2 3)) =>  (3)
(last '(1 2 . 3)) =>  (2 . 3)
(setq x (list 'a 'b 'c 'd)) =>  (A B C D)
(last x) =>  (D)
(rplacd (last x) (list 'e 'f)) x =>  (A B C D E F)
(last x) =>  (F)

(last '(a b c))   =>  (C)

(last '(a b c) 0) =>  ()
(last '(a b c) 1) =>  (C)
(last '(a b c) 2) =>  (B C)
(last '(a b c) 3) =>  (A B C)
(last '(a b c) 4) =>  (A B C)

(last '(a . b) 0) =>  B
(last '(a . b) 1) =>  (A . B)
(last '(a . b) 2) =>  (A . B)
```

Side Effects: None.

Affected By: None.

Exceptional Situations:

The consequences are undefined if list is a circular list. Should signal an error of type type-error if n is not a non-negative integer.

Notes:

The following code could be used to define last.

``` (defun last (list &optional (n 1))
(check-type n (integer 0))
(do ((l list (cdr l))
(r list)
(i 0 (+ i 1)))
((atom l) r)
(if (>= i n) (pop r))))
```

The following X3J13 cleanup issues, not part of the specification, apply to this section: