diff --git a/binary-file.cabal b/binary-file.cabal
--- a/binary-file.cabal
+++ b/binary-file.cabal
@@ -2,7 +2,7 @@
 cabal-version:	>= 1.8
 
 name:		binary-file
-version:	0.3
+version:	0.4
 stability:	experimental
 author:		Yoshikuni Jujo <PAF01143@nifty.ne.jp>
 maintainer:	Yoshikuni Jujo <PAF01143@nifty.ne.jp>
@@ -20,11 +20,13 @@
     .
     > import Binary
     > import System.Environment
+    > import Data.ByteString as BS
     >
     > main = do
     >	[inf, outf] <- getArgs
     >
-    >	cnt <- readBinaryFile inf
+    >	-- cnt <- readBinaryFile inf
+    >   cnt <- BS.readFile inf
     >	let bmp = readBitmap cnt
     >	print $ readBitmap cnt
     >
@@ -32,7 +34,8 @@
     >		authorFirst = "Yoshikuni ",
     >		authorSecond = "Jujo      "
     >	 }
-    >	writeBinaryFile outf out
+    >	-- writeBinaryFile outf out
+    >   BS.writeFile outf out
     >
     > [binary|
     >
@@ -55,7 +58,8 @@
     > 4: numberOfColors
     > 4: importantColors
     > 4[numberOfColors]: colors
-    > bitsPerPixel/8[imageSize*8/bitsPerPixel]: image
+    > -- bitsPerPixel/8[imageSize*8/bitsPerPixel]: image
+    > imageSize<ByteString>: image
     > 10<String>: authorFirst
     > 10<String>: authorSecond
     > 
@@ -66,5 +70,5 @@
     hs-source-dirs:	src
     exposed-modules:	Binary
     other-modules:	QuoteBinaryStructure, ParseBinaryStructure, Here
-    build-depends:	base > 3 && < 5, template-haskell, peggy
+    build-depends:	base > 3 && < 5, template-haskell, peggy, bytestring
     ghc-options:	-Wall
diff --git a/src/ParseBinaryStructure.hs b/src/ParseBinaryStructure.hs
--- a/src/ParseBinaryStructure.hs
+++ b/src/ParseBinaryStructure.hs
@@ -44,8 +44,9 @@
 4: neededIndexNumber
 
 4[colorIndexNumber]: colors
-1[3]: image
+-- 1[3]: image
 10<String>: author
+10<ByteString>: hoge
 
 |]
 
@@ -64,7 +65,7 @@
 constantInt (ConstantInt v) = v
 constantInt (ConstantString v) = readInt v
 
-data Type = String | Int deriving Show
+data Type = String | Int | ByteString deriving Show
 
 data VariableValue
 	= VariableValue { variableValue :: String }
@@ -127,11 +128,13 @@
 				{ BinaryStructure $2 $4 }
 
 emptyLines :: ()
-	= [ \n]*		{ () }
+	= "--" [^\n]* [\n]	{ () }
+	/ [ \n]*		{ () }
 
 spaces :: ()
 	= [ ]*			{ () }
 
+
 name :: String
 	= [A-Z][a-zA-Z0-9]*	{ $1 : $2 }
 
@@ -140,6 +143,7 @@
 				{ binaryStructureItem $1 $2 $3 $5 }
 type :: Type
 	= "<String>"		{ String }
+	/ "<ByteString>"	{ ByteString }
 	/ "<Int>"?		{ Int }
 
 expr :: Expression
diff --git a/src/QuoteBinaryStructure.hs b/src/QuoteBinaryStructure.hs
--- a/src/QuoteBinaryStructure.hs
+++ b/src/QuoteBinaryStructure.hs
@@ -1,4 +1,9 @@
-{-# LANGUAGE TemplateHaskell, TupleSections, PatternGuards #-}
+{-# LANGUAGE
+	TemplateHaskell,
+	TupleSections,
+	PatternGuards,
+	TypeSynonymInstances,
+	FlexibleInstances #-}
 
 module QuoteBinaryStructure (
 	binary
@@ -18,6 +23,8 @@
 
 import ParseBinaryStructure
 
+import qualified Data.ByteString as BS
+
 main = do
 	runQ (mkHaskellTree $ parseBinaryStructure "BinaryFileHeader") >>= print
 
@@ -34,6 +41,7 @@
 	binaryStructureName = bsn,
 	binaryStructureBody = body } = do
 		d <- mkData bsn body
+--		dbg <- debugReadType
 		r <- mkReader bsn body
 		w <- mkWriter bsn body
 		return [d, r, w]
@@ -41,20 +49,22 @@
 mkWriter :: String -> [BinaryStructureItem] -> DecQ
 mkWriter bsn body = do
 	bs <- newName "bs"
-	let run = appE (varE 'concat) $ listE $ map
+	let run = appE (varE 'cc) $ listE $ map
 		(\bsi -> writeField bs (bytesOf bsi) (typeOf bsi) (sizeOf bsi) (valueOf bsi))
 		body
 	funD (mkName $ "write" ++ bsn)
 		[clause [varP bs] (normalB run) []]
 
-writeField :: Name -> Expression -> Type -> Maybe Expression -> Either Int String -> ExpQ
+writeField :: Name -> Expression -> Type -> Maybe Expression ->
+	Either Int String -> ExpQ
 writeField bs size Int Nothing (Left n) =
-	appsE [varE 'intToBin, expression bs size, litE $ integerL $ fromIntegral n]
+	appsE [varE 'fi, expression bs size, litE $ integerL $ fromIntegral n]
 writeField bs size Int Nothing (Right v) =
-	appsE [varE 'intToBin, expression bs size, getField bs v]
-writeField bs size Int (Just n) (Right v) = appsE [varE 'concatMap,
-	appE (varE 'intToBin) (expression bs size), getField bs v]
-writeField bs size String Nothing (Right v) = getField bs v
+	appsE [varE 'fi, expression bs size, getField bs v]
+writeField bs size Int (Just n) (Right v) = appE (varE 'cc) $ appsE [varE 'map,
+	appE (varE 'fi) (expression bs size), getField bs v]
+writeField bs size String Nothing (Right v) = appE (varE 'fs) $ getField bs v
+writeField bs size ByteString Nothing (Right v) = appE (varE 'fbs) $ getField bs v
 
 intToBin :: Int -> Int -> String
 intToBin n x = intToBinGen (fromIntegral n) (fromIntegral x)
@@ -64,6 +74,11 @@
 intToBinGen n x = chr (fromIntegral $ x `mod` 256) :
 	intToBinGen (n - 1) (x `div` 256)
 
+-- readerType :: String -> DecQ
+-- readerType = sigD (mkName $ "read" ++ bsn) [t| Str a => a ->
+
+-- debugReadType :: DecQ = [d| readBitmap :: Str a => a -> Bitmap |]
+
 mkReader :: String -> [BinaryStructureItem] -> DecQ
 mkReader bsn body = do
 	cs <- newName "cs"
@@ -88,16 +103,22 @@
 	    | Left val <- valueOf item = do
 		cs'' <- newName "cs"
 		let t = dropE' n $ varE cs'
-		let p = val `equal` appE (varE 'readInt) (takeE' n $ varE cs')
+		let p = val `equal` appE (varE 'ti) (takeE' n $ varE cs')
 		let e = [e| error "bad value" |]
 		d <- valD (varP cs'') (normalB $ condE p t e) []
 		return ([d], cs'')
 	    | Right var <- valueOf item, Nothing <- sizeOf item, Int <- typeOf item = do
 		cs'' <- newName "cs"
 		def <- valD (varP $ fromJust $ lookup var np)
-			(normalB $ appE (varE 'readInt) $ takeE' n $ varE cs') []
+			(normalB $ appE (varE 'ti) $ takeE' n $ varE cs') []
 		next <- valD (varP cs'') (normalB $ dropE' n $ varE cs') []
 		return ([def, next], cs'')
+	    | Right var <- valueOf item, Nothing <- sizeOf item, ByteString <- typeOf item = do
+		cs'' <- newName "cs"
+		def <- valD (varP $ fromJust $ lookup var np)
+			(normalB $ takeE'' n $ varE cs') []
+		next <- valD (varP cs'') (normalB $ dropE' n $ varE cs') []
+		return ([def, next], cs'')
 	    | Right var <- valueOf item, Nothing <- sizeOf item = do
 		cs'' <- newName "cs"
 		def <- valD (varP $ fromJust $ lookup var np)
@@ -108,12 +129,13 @@
 		cs'' <- newName "cs"
 		def <- valD (varP $ fromJust $ lookup var np)
 			(normalB $
-				appsE [varE 'map, varE 'readInt,
+				appsE [varE 'map, varE 'ti,
 				appsE [varE 'devideN, n,
 			takeE' (multiE' n $ expression ret expr) $ varE cs']]) []
 		next <- valD (varP cs'') (normalB $
 			dropE' (multiE' n $ expression ret expr) $ varE cs') []
 		return ([def, next], cs'')
+	    | otherwise = error $ show $ typeOf item
 	    where
 	    n = expression ret $ bytesOf item
 
@@ -138,17 +160,20 @@
 equal :: Int -> ExpQ -> ExpQ
 equal x y = infixE (Just $ litE $ integerL $ fromIntegral x) (varE '(==)) (Just y)
 
-takeE :: Int -> ExpQ -> ExpQ
-takeE n xs = appsE [varE 'take, litE $ integerL $ fromIntegral n, xs]
+-- takeE :: Int -> ExpQ -> ExpQ
+-- takeE n xs = appsE [varE 'tk, litE $ integerL $ fromIntegral n, xs]
 
 takeE' :: ExpQ -> ExpQ -> ExpQ
-takeE' n xs = appsE [varE 'take, n, xs]
+takeE' n xs = appE (varE 'ts) $ appsE [varE 'tk, n, xs]
 
-dropE :: Int -> ExpQ -> ExpQ
-dropE n xs = appsE [varE 'drop, litE $ integerL $ fromIntegral n, xs]
+takeE'' :: ExpQ -> ExpQ -> ExpQ
+takeE'' n xs = appE (varE 'tbs) $ appsE [varE 'tk, n, xs]
 
+-- dropE :: Int -> ExpQ -> ExpQ
+-- dropE n xs = appsE [varE 'dp, litE $ integerL $ fromIntegral n, xs]
+
 dropE' :: ExpQ -> ExpQ -> ExpQ
-dropE' n xs = appsE [varE 'drop, n, xs]
+dropE' n xs = appsE [varE 'dp, n, xs]
 
 gather :: Monad m => s -> [a] -> (a -> s -> m ([b], s)) -> m [b]
 gather s [] f = return []
@@ -173,9 +198,12 @@
 				(mkName $ fromRight $ valueOf item) $
 					strictType notStrict $
 						appT listT $ conT ''Int
-			(Nothing, _) -> varStrictType
+			(Nothing, String) -> varStrictType
 				(mkName $ fromRight $ valueOf item) $
 					strictType notStrict $ conT ''String
+			(Nothing, ByteString) -> varStrictType
+				(mkName $ fromRight $ valueOf item) $
+					strictType notStrict $ conT ''BS.ByteString
 
 	isRight item
 		| Right _ <- valueOf item = True
@@ -186,3 +214,36 @@
 devideN :: Int -> [a] -> [[a]]
 devideN _ [] = []
 devideN n xs = take n xs : devideN n (drop n xs)
+
+class Str a where
+	tk :: Int -> a -> a
+	dp :: Int -> a -> a
+	ts :: a -> String
+	fs :: String -> a
+	fbs :: BS.ByteString -> a
+	tbs :: a -> BS.ByteString
+	ti :: a -> Int
+	fi :: Int -> Int -> a
+	cc :: [a] -> a
+
+instance Str String where
+	tk = take
+	dp = drop
+	ts = id
+	fs = id
+	fbs = ts
+	tbs = fs
+	ti = readInt
+	fi = intToBin
+	cc = concat
+
+instance Str BS.ByteString where
+	tk = BS.take
+	dp = BS.drop
+	ts = map (chr . fromIntegral) . BS.unpack
+	fs = BS.pack . map (fromIntegral . ord)
+	fbs = id
+	tbs = id
+	ti = readInt . map (chr . fromIntegral) . BS.unpack
+	fi n = BS.pack . map (fromIntegral . ord) . intToBin n
+	cc = BS.concat