Fix formatting and errors

src/Constraint.hs

@@ -1,15 +1,16 @@
-module Constraint where
+module Constraint
+  ( Constraint(..)
+  , inRange
+  , inside
+  ) where
 
 data Constraint = Constraint
   { lower :: Int
   , upper :: Int
   } deriving (Show, Eq)
 
-makeRangeFromNumber :: Int -> Constraint
-makeRangeFromNumber x = Constraint x x
-
 inside :: (Int, Int) -> Constraint -> Bool
-inside (x, y) (Constraint lower upper) = x >= lower && y <= upper
+inside (x, y) (Constraint lw up) = x >= lw && y <= up
 
 inRange :: Int -> Constraint -> Bool
 inRange x = inside (x, x)

src/Field.hs

@@ -1,4 +1,6 @@
-module Field where
+module Field
+  ( module Field
+  ) where
 
 import           Constraint
 import           Data.Char  (isDigit)
@@ -44,11 +46,12 @@ parseFieldRange text constraint
   | text == "*" = Just All
   | isJust number = Just (Range (fromJust number) (fromJust number))
   | isJust range = Just (uncurry Range (fromJust range))
-  | isJust sequence = fmap Sequence sequence
+  | isJust valueSequence = fmap Sequence valueSequence
+  | otherwise = Nothing
   where
     number = parseNumber text constraint
     range = parseRange text constraint
-    sequence = parseSequence text constraint
+    valueSequence = parseSequence text constraint
 
 isNumber :: String -> Bool
 isNumber = all isDigit

src/Helper.hs

@@ -1,4 +1,6 @@
-module Helper where
+module Helper
+  ( wordsWhen
+  ) where
 
 wordsWhen :: (Char -> Bool) -> String -> [String]
 wordsWhen p s =

src/Pattern.hs

@@ -1,11 +1,9 @@
 module Pattern
   ( Pattern(..)
   , match
-  , safeMatch
   , parse
   , check
-  , createParts
-  , parseField
+  , createFields
   ) where
 
 import           Constraint
@@ -20,16 +18,10 @@ data Pattern = Pattern
   , cmonth  :: Field
   , cweek   :: Field
   , cyear   :: Field
-  }
+  } deriving (Show)
 
-match :: String -> DateTime -> Bool
+match :: String -> DateTime -> Maybe Bool
 match s d =
-  case parse s of
-    Just p  -> check p d
-    Nothing -> error "Parse error"
-
-safeMatch :: String -> DateTime -> Maybe Bool
-safeMatch s d =
   case parse s of
     Just p  -> Just (check p d)
     Nothing -> Nothing
@@ -39,7 +31,7 @@ parse s
   | isInvalid = Nothing
   | otherwise = Just (createPattern $ catMaybes parts)
   where
-    parts = createParts s
+    parts = createFields s
     isInvalid = not (checkParts parts)
     createPattern xs =
       Pattern
@@ -51,9 +43,10 @@ parse s
       , cyear = xs !! 5
       }
 
-createParts s = zipWith (curry f) parsers (words s)
+createFields :: String -> [Maybe Field]
+createFields text = zipWith (curry f) parsers (words text)
   where
-    f (g, s) = g s
+    f (parser, s) = parser s
 
 checkParts :: [Maybe Field] -> Bool
 checkParts xs
@@ -64,18 +57,25 @@ checkParts xs
 parseFieldAdapter :: Constraint -> String -> Maybe Field
 parseFieldAdapter c t = parseField t c
 
+parseMinute :: String -> Maybe Field
 parseMinute = parseFieldAdapter (Constraint 0 59)
 
-parseHour = parseFieldAdapter (Constraint 0 59)
+parseHour :: String -> Maybe Field
+parseHour = parseFieldAdapter (Constraint 0 23)
 
+parseDay :: String -> Maybe Field
 parseDay = parseFieldAdapter (Constraint 1 31)
 
+parseMonth :: String -> Maybe Field
 parseMonth = parseFieldAdapter (Constraint 1 12)
 
+parseWeek :: String -> Maybe Field
 parseWeek = parseFieldAdapter (Constraint 1 7)
 
+parseYear :: String -> Maybe Field
 parseYear = parseFieldAdapter (Constraint 0 9999)
 
+parsers :: [String -> Maybe Field]
 parsers = [parseMinute, parseHour, parseDay, parseMonth, parseWeek, parseYear]
 
 check :: Pattern -> DateTime -> Bool