+(test (expand-pattern-matches
+ '((data A (foo Int Int))
+ (let ([(foo x y) (foo 123 234)] [z (f 123)]) x)))
+ '((data A (foo Int Int))
+ (let ([x (foo~0 (foo 123 234))]
+ [y (foo~1 (foo 123 234))]
+ [z (f 123)])
+ x)))
+
+(test (singletons '((A [foo] [bar Int]) (B [baz Int] [qux])))
+ '(foo qux))
+
+(test (map (lambda (x) (data-sum-tag '((A [foo] [bar Int]) (B [baz Int] [qux])) x))
+ '(foo bar baz qux))
+ '(0 1 0 1))
+
+(test-exception
+ (expand-pattern-matches '((data A (foo Int Int))
+ (let ([(foo x) (foo 123 234)])
+ x))))
+