Common Lisp - simple function examples, Common Lisp

Language: Layout:

(defun our-last (list)
    (cond
        ((null (cdr list)) (car list))
        (T (our-last (cdr list)))
    )
)

(defun count-x-in-y (x y)
    (cond
        ((null (cdr y))
            (cond
                ((equalp (car y) x) 1)
                (T 0)
            )
        )
        (T
            (cond
                ((equalp (car y) x) (+ 1 (count-x-in-y x (cdr y))))
                (T (count-x-in-y x (cdr y)))
            )
        )
    )
)

(defun sum (list)
    (cond
        ((null (car list)) 0)
        ((numberp (car list)) (+ (car list) (sum (cdr list))))
        (T (sum (cdr list)))
    )
)

(defun count-numbers-in-list (list)
    (cond
        ((null (car list)) 0)
        ((numberp (car list)) (+ 1 (count-numbers-in-list (cdr list))))
        (T (count-numbers-in-list (cdr list)))
    )
)

(defun average-r (list)
    (/ (sum list) (count-numbers-in-list list))
)

(defun squash-list (list)
    (cond
        ((null (car list)) NIL)
        ((listp (car list)) (append (squash-list (car list)) (squash-list (cdr list))))
        (T (append (list (car list)) (squash-list (cdr list))))
    )
)

(defun our-member-p (x y)
    (cond
        ((null (car y)) NIL)
        ((equalp (car y) x) x)
        (T (our-member-p x (cdr y)))
    )
)

; Test lists
(setf a (list 2 3 'b 3 5 5 5))
(setf c '((x y) x ((((y z))))))

; Test cases
(print (our-last a))
(print (count-x-in-y 5 a))

; Helper functions for average-r
(print (sum a))
(print (count-numbers-in-list a))

(print (average-r a))
(print (our-member-p 'b a))
(print (squash-list c))

[ + ] Show input
Absolute running time: 0.15 sec, cpu time: 0.02 sec, memory peak: 9 Mb, absolute service time: 0,2 sec