X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=Data%2FEither.hs;h=6ffc607303751d47d3c24def28d2dec88886e065;hb=HEAD;hp=6af488fc9fb8a0189efe009cb5f7c12a9e24f140;hpb=0a7a4a16e555a77afec5501a75d9fbbb9fc35730;p=ghc-base.git

diff --git a/Data/Either.hs b/Data/Either.hs
index 6af488f..6ffc607 100644
--- a/Data/Either.hs
+++ b/Data/Either.hs
@@ -1,4 +1,8 @@
-{-# OPTIONS_GHC -XNoImplicitPrelude #-}
+{-# LANGUAGE CPP, NoImplicitPrelude #-}
+#ifdef __GLASGOW_HASKELL__
+{-# LANGUAGE DeriveDataTypeable, DeriveGeneric, StandaloneDeriving #-}
+#endif
+
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Data.Either
@@ -30,6 +34,7 @@ import GHC.Read
 #endif
 
 import Data.Typeable
+import GHC.Generics (Generic)
 
 #ifdef __GLASGOW_HASKELL__
 {-
@@ -47,7 +52,8 @@ either correct or an error; by convention, the 'Left' constructor is
 used to hold an error value and the 'Right' constructor is used to
 hold a correct value (mnemonic: \"right\" also means \"correct\").
 -}
-data  Either a b  =  Left a | Right b   deriving (Eq, Ord, Read, Show)
+data  Either a b  =  Left a | Right b
+  deriving (Eq, Ord, Read, Show, Generic)
 
 -- | Case analysis for the 'Either' type.
 -- If the value is @'Left' a@, apply the first function to @a@;
@@ -79,8 +85,8 @@ rights x = [a | Right a <- x]
 partitionEithers :: [Either a b] -> ([a],[b])
 partitionEithers = foldr (either left right) ([],[])
  where
-  left  a (l, r) = (a:l, r)
-  right a (l, r) = (l, a:r)
+  left  a ~(l, r) = (a:l, r)
+  right a ~(l, r) = (l, a:r)
 
 {-
 {--------------------------------------------------------------------