+++ /dev/null
-\r
-data List a = Nil | Cons a (List a)\r
-\r
-hasEvenLength :: List a -> Boolean\r
-hasEvenLength l = do \r
- even Nil = True\r
- even (Cons _ t) = odd t\r
- odd Nil = False\r
- odd (Cons _ t) = even t\r
- even l\r
-\r
-main = hasEvenLength (Cons (1 :: Integer) (Cons (2 :: Integer) (Cons (3 :: Integer) (Cons (4 :: Integer) Nil))))\r
---\r
-true
\ No newline at end of file