X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=System%2FTimeout.hs;h=df33625c8d4cca3f8b51052c4c87492481d4cd5f;hb=HEAD;hp=0e82704a850b9996b5fa6ea7529349ca4ea57145;hpb=a2bcd1899dea9b266b7c795e391f658985deda2e;p=ghc-base.git

diff --git a/System/Timeout.hs b/System/Timeout.hs
index 0e82704..df33625 100644
--- a/System/Timeout.hs
+++ b/System/Timeout.hs
@@ -1,3 +1,8 @@
+{-# LANGUAGE CPP #-}
+#ifdef __GLASGOW_HASKELL__
+{-# LANGUAGE DeriveDataTypeable, StandaloneDeriving #-}
+#endif
+
 -------------------------------------------------------------------------------
 -- |
 -- Module      :  System.Timeout
@@ -12,22 +17,19 @@
 --
 -------------------------------------------------------------------------------
 
+#ifdef __GLASGOW_HASKELL__
 #include "Typeable.h"
+#endif
 
 module System.Timeout ( timeout ) where
 
-#if __NHC__
-timeout :: Int -> IO a -> IO (Maybe a)
-timeout n f = fmap Just f
-#else
-
+#ifdef __GLASGOW_HASKELL__
 import Prelude             (Show(show), IO, Ord((<)), Eq((==)), Int,
-                            (.), otherwise, fmap)
+                            otherwise, fmap)
 import Data.Maybe          (Maybe(..))
-import Control.Monad       (Monad(..), guard)
+import Control.Monad       (Monad(..))
 import Control.Concurrent  (forkIO, threadDelay, myThreadId, killThread)
 import Control.Exception   (Exception, handleJust, throwTo, bracket)
-import Data.Dynamic        (Typeable, fromDynamic)
 import Data.Typeable
 import Data.Unique         (Unique, newUnique)
 
@@ -35,13 +37,14 @@ import Data.Unique         (Unique, newUnique)
 -- interrupt the running IO computation when the timeout has
 -- expired.
 
-data Timeout = Timeout Unique deriving Eq
+newtype Timeout = Timeout Unique deriving Eq
 INSTANCE_TYPEABLE0(Timeout,timeoutTc,"Timeout")
 
 instance Show Timeout where
     show _ = "<<timeout>>"
 
 instance Exception Timeout
+#endif /* !__GLASGOW_HASKELL__ */
 
 -- |Wrap an 'IO' computation to time out and return @Nothing@ in case no result
 -- is available within @n@ microseconds (@1\/10^6@ seconds). In case a result
@@ -73,6 +76,7 @@ instance Exception Timeout
 -- I\/O or file I\/O using this combinator.
 
 timeout :: Int -> IO a -> IO (Maybe a)
+#ifdef __GLASGOW_HASKELL__
 timeout n f
     | n <  0    = fmap Just f
     | n == 0    = return Nothing
@@ -84,4 +88,6 @@ timeout n f
                    (bracket (forkIO (threadDelay n >> throwTo pid ex))
                             (killThread)
                             (\_ -> fmap Just f))
-#endif
+#else
+timeout n f = fmap Just f
+#endif /* !__GLASGOW_HASKELL__ */