Data commit

Task/Playing-cards/ACL2/playing-cards.acl2

@@ -0,0 +1,52 @@
+(defun remove-nth (i xs)
+   (if (or (zp i) (endp (rest xs)))
+       (rest xs)
+       (cons (first xs)
+             (remove-nth (1- i) (rest xs)))))
+
+(defthm remove-nth-shortens
+   (implies (consp xs)
+            (< (len (remove-nth i xs)) (len xs))))
+
+:set-state-ok t
+
+(defun shuffle-r (xs ys state)
+   (declare (xargs :measure (len xs)))
+   (if (endp xs)
+       (mv ys state)
+       (mv-let (idx state)
+               (random$ (len xs) state)
+          (shuffle-r (remove-nth idx xs)
+                     (cons (nth idx xs) ys)
+                     state))))
+
+(defun shuffle (xs state)
+   (shuffle-r xs nil state))
+
+(defun cross-r (x ys)
+   (if (endp ys)
+       nil
+       (cons (cons x (first ys))
+             (cross-r x (rest ys)))))
+
+(defun cross (xs ys)
+   (if (or (endp xs) (endp ys))
+       nil
+       (append (cross-r (first xs) ys)
+               (cross (rest xs) ys))))
+
+(defun make-deck ()
+   (cross '(ace 2 3 4 5 6 7 8 9 10 jack queen king)
+          '(hearts diamonds clubs spades)))
+
+(defun print-card (card)
+   (cw "~x0 of ~x1~%" (car card) (cdr card)))
+
+(defun print-deck (deck)
+   (if (endp deck)
+       nil
+       (progn$ (print-card (first deck))
+               (print-deck (rest deck)))))
+
+(defun draw-from-deck (deck)
+   (mv (first deck) (rest deck)))