Support older ghc and fix warnings

Author: dcoutts

Codec/Compression/Zlib/Stream.hsc

@@ -109,15 +109,19 @@ import qualified Data.ByteString.Unsafe as B
 import Data.ByteString (ByteString)
 import Control.Applicative (Applicative(..))
 import Control.Monad (ap,liftM)
+#if __GLASGOW_HASKELL__ >= 702
+import Control.Monad.ST.Strict hiding (unsafeIOToST)
+import Control.Monad.ST.Unsafe
+#else
+import Control.Monad.ST.Strict
+#endif
 import Control.Exception (assert)
 #ifdef DEBUG
 import System.IO (hPutStrLn, stderr)
 #endif
 
 import Prelude hiding (length)
 
-import Control.Monad.ST.Strict
-
 #include "zlib.h"
 
 

zlib.cabal

@@ -34,7 +34,10 @@ library
                    Codec.Compression.Zlib.Raw,
                    Codec.Compression.Zlib.Internal
   other-modules:   Codec.Compression.Zlib.Stream
-  default-language: Haskell2010
+  if impl(ghc < 7)
+    default-language: Haskell98
+  else
+    default-language: Haskell2010
   other-extensions: CPP, ForeignFunctionInterface, RankNTypes, BangPatterns
   build-depends:   base >= 3 && < 5,
                    bytestring >= 0.9 && < 0.12