(declare (optimize speed))
(adjoin elt '(:y))))
':x)))
+
+
+(macrolet ((test (expected list-1 list-2 &rest args)
+ `(progn
+ (assert (equal ,expected (funcall #'union ,list-1 ,list-2 ,@args)))
+ (assert (equal ,expected (funcall #'nunion
+ (copy-list ,list-1)
+ (copy-list ,list-2)
+ ,@args))))))
+ (test nil nil nil)
+ (test '(42) nil '(42))
+ (test '(42) '(42) nil)
+ (test '(42) '(42) '(42))
+ (test '((42) (42)) '((42)) '((42)))
+ (test '((42) (42)) '((42)) '((42)) :test-not #'equal)
+ (test '((42)) '((42)) '((42)) :test #'equal)
+ (test '((42)) '((42)) '((42)) :key #'car)
+ (test '((42)) '((42)) '((42)) :key #'car :test-not #'<))
+