diff --git a/src/PDF/Text.hs b/src/PDF/Text.hs
index ec40769..150edc2 100644
--- a/src/PDF/Text.hs
+++ b/src/PDF/Text.hs
@@ -5,7 +5,7 @@ module PDF.Text {-(
   )-} where
 
 import Control.Applicative ((<|>))
-import Control.Monad (foldM, join)
+import Control.Monad (foldM)
 import Control.Monad.Reader (ReaderT, runReaderT, asks)
 import Control.Monad.State (get, put)
 import Data.Attoparsec.ByteString.Char8 (choice, count, sepBy)
@@ -18,7 +18,7 @@ import PDF.Object (
       DirectObject(..), StringObject(..)
     , array, blank, name, parseBytes, regular, stringObject
   )
-import PDF.Parser (MonadParser, Parser, evalParser, string, takeAll)
+import PDF.Parser (MonadParser, (<?>), Parser, evalParser, string, takeAll)
 
 data StateOperator =
   Cm | W | J | J_ | M | D | Ri | I | Gs -- general graphic state
@@ -40,24 +40,22 @@ stateOperator M = (,) M <$> count 1 argument <* string "M"
 stateOperator D = (,) D <$> count 2 argument <* string "d"
 stateOperator Ri = (,) Ri <$> count 1 argument <* string "ri"
 stateOperator I = (,) I <$> count 1 argument <* string "i"
-stateOperator Gs = (,) Gs <$> count 1 argument <* string "gs"
+stateOperator Gs = (,) Gs <$> count 1 nameArg <* string "gs"
 
 textOperator :: MonadParser m => TextOperator -> m (Call TextOperator)
 textOperator Td = (,) Td <$> count 2 argument <* string "Td"
 textOperator TD = (,) TD <$> count 2 argument <* string "TD"
 textOperator Tm = (,) Tm <$> count 6 argument <* string "Tm"
 textOperator Tstar = (,) Td <$> return [] <* string "T*"
-textOperator TJ =
-  (,) TJ <$> sequence [Typed . Array <$> array] <* blank <* string "TJ"
-textOperator Tj =
-  (,) Tj <$> sequence [Typed . StringObject <$> stringObject] <* blank <* string "Tj"
-textOperator Quote = (,) Quote <$> count 1 argument <* string "'"
-textOperator DQuote = (,) DQuote <$> count 1 argument <* string "\""
+textOperator TJ = (,) TJ <$> count 1 arrayArg <* string "TJ"
+textOperator Tj = (,) Tj <$> count 1 stringArg <* string "Tj"
+textOperator Quote = (,) Quote <$> count 1 stringArg <* string "'"
+textOperator DQuote = (,) DQuote <$> count 1 stringArg <* string "\""
 textOperator Tc = (,) Tc <$> count 1 argument <* string "Tc"
 textOperator Tw = (,) Tw <$> count 1 argument <* string "Tw"
 textOperator Tz = (,) Tz <$> count 1 argument <* string "Tz"
 textOperator TL = (,) TL <$> count 1 argument <* string "TL"
-textOperator Tf = (,) Tf <$> sequence [Typed . NameObject <$> name, argument] <* string "Tf"
+textOperator Tf = (,) Tf <$> sequence [nameArg, argument] <* string "Tf"
 textOperator Tr = (,) Tr <$> count 1 argument <* string "Tr"
 textOperator Ts = (,) Ts <$> count 1 argument <* string "Ts"
 
@@ -67,6 +65,15 @@ a parserGenerator = choice $ parserGenerator <$> [minBound .. maxBound]
 argument :: MonadParser m => m Argument
 argument = Raw <$> takeAll regular <* blank
 
+arrayArg :: MonadParser m => m Argument
+arrayArg = Typed . Array <$> array <* blank
+
+nameArg :: MonadParser m => m Argument
+nameArg = Typed . NameObject <$> name <* blank
+
+stringArg :: MonadParser m => m Argument
+stringArg = Typed . StringObject <$> stringObject <* blank
+
 data PageContents = PageContents {
     chunks :: [ByteString]
   }
@@ -78,20 +85,20 @@ pageContents font input =
   evalParser (runReaderT (PageContents <$> page) font) emptyCMap input
 
 page :: ParserWithFont [ByteString]
-page = graphicState <|> text
+page = graphicState <|> text <?> "Text page contents"
 
 graphicState :: ParserWithFont [ByteString]
 graphicState =
-  string "q" *> blank *> insideQ <* string "Q"
+  (string "q" *> blank *> insideQ <* blank <* string "Q") <?> "Graphic state"
   where
-    insideQ = join <$> ((command <|> page) `sepBy` blank )
+    insideQ = concat <$> ((command <|> page) `sepBy` blank )
     command = a stateOperator *> return []
 
 text :: ParserWithFont [ByteString]
 text =
-  string "BT" *> blank *> commands <* blank <* string "ET"
+  string "BT" *> blank *> commands <* blank <* string "ET" <?> "Text operators"
   where
-    commands = join <$> (a textOperator >>= runOperator) `sepBy` blank
+    commands = concat <$> (a textOperator >>= runOperator) `sepBy` blank
 
 runOperator :: Call TextOperator -> ParserWithFont [ByteString]
 runOperator (Tf, [Typed (NameObject fontName), _]) =