Try and fix stuff by generalizing a signature to ease debugging and add parenthesis which I think should have been here all along

src/PDF/Text.hs

@@ -1,8 +1,8 @@
 {-# LANGUAGE OverloadedStrings #-}
-module PDF.Text (
+module PDF.Text {-(
       PageContents(..)
     , pageContents
-  ) where
+  )-} where
 
 import Control.Applicative ((<|>))
 import Control.Monad (foldM, join)
@@ -61,7 +61,7 @@ textOperator Tf = (,) Tf <$> sequence [Typed . NameObject <$> name, argument] <*
 textOperator Tr = (,) Tr <$> count 1 argument <* string "Tr"
 textOperator Ts = (,) Ts <$> count 1 argument <* string "Ts"
 
-a :: (Bounded o, Enum o) => (o -> ParserWithFont (Call o)) -> ParserWithFont (Call o)
+a :: (Bounded o, Enum o, MonadParser m) => (o -> m (Call o)) -> m (Call o)
 a parserGenerator = choice $ parserGenerator <$> [minBound .. maxBound]
 
 argument :: MonadParser m => m Argument
@@ -84,7 +84,7 @@ graphicState :: ParserWithFont [ByteString]
 graphicState =
   string "q" *> blank *> insideQ <* string "Q"
   where
-    insideQ = join <$> (command <|> page `sepBy` blank )
+    insideQ = join <$> ((command <|> page) `sepBy` blank )
     command = a stateOperator *> return []
 
 text :: ParserWithFont [ByteString]