fixed up split in day 4

day4.hs

@@ -9,7 +9,7 @@ import Data.List (sort, nub)
 main :: IO ()
 main = do
   raw <- readFile "day4.txt"
-  let ls = parse $ lines raw
+  let ls = map (concat . (map words)) $ split "" $ lines raw
       ansA = length $ filter (== True) $ map solveA ls
       ansB = length $ filter (== True) $ map solveB ls
    in do 
@@ -96,12 +96,9 @@ hgtValid s' =
     s = drop 1 $ dropWhile (/= ':') s'
     (val,unit) = head $ (reads s :: [(Int,String)])
 
-parse :: [String] -> [[String]]
-parse [] = []
-parse s = parse' s [] []
-
-parse' :: [String] -> [String] -> [[String]] -> [[String]]
-parse' [] as bs = bs ++ [as]
-parse' (s:ss) as bs
-  | s == "" = parse' ss [] $ bs ++ [as]
-  | otherwise = parse' ss (as ++ (words s)) bs
+split :: Eq a => a -> [a] -> [[a]]
+split _ [] = []
+split d as = chunk : (split d rest)
+  where
+    chunk = takeWhile (/= d) as
+    rest = drop 1 $ dropWhile (/= d) as