*Main> compress "aaabbbbvvvcccaaaddd"
"abvcad*** Exception: Documents/Haskell/excercise.hs:(15,56)-(19,59): Non-exhaustive patterns in case
何がたりなんだろうか。
compress :: (Eq a) => [a] -> [a]
compress list = case (list) of
[] -> []
(_:_) -> (findDuplicate list) : (compress (deleteDuplicate list (findDuplicate list)))
where
findDuplicate :: (Eq a) => [a] -> a
findDuplicate list = case (list) of
[] -> error""
[x]->x
(x:y:xs)
| x==y-> findDuplicate (y:xs)
| otherwise -> x

deleteDuplicate :: (Eq a) => [a] -> a -> [a]
deleteDuplicate list element = case (list) of
[] -> []
(x:y:xs)
| x == element -> deleteDuplicate (y:xs) element
| otherwise -> list