X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=Data%2FEither.hs;h=1c12897eaad3230d83b9111be1e0d4a3d6b82f9e;hb=41e8fba828acbae1751628af50849f5352b27873;hp=cb71eaa8d5c5ec4c1896a7fcd311e17b3ab02349;hpb=82d74b928620a26c07351e9b89f5cf0106e3efac;p=ghc-base.git

diff --git a/Data/Either.hs b/Data/Either.hs
index cb71eaa..1c12897 100644
--- a/Data/Either.hs
+++ b/Data/Either.hs
@@ -1,4 +1,5 @@
-{-# OPTIONS_GHC -XNoImplicitPrelude #-}
+{-# LANGUAGE CPP, NoImplicitPrelude #-}
+
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Data.Either
@@ -21,10 +22,17 @@ module Data.Either (
    partitionEithers, -- :: [Either a b] -> ([a],[b])
  ) where
 
+#include "Typeable.h"
+
 #ifdef __GLASGOW_HASKELL__
 import GHC.Base
 import GHC.Show
+import GHC.Read
+#endif
+
+import Data.Typeable
 
+#ifdef __GLASGOW_HASKELL__
 {-
 -- just for testing
 import Test.QuickCheck
@@ -40,7 +48,7 @@ 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, Show)
+data  Either a b  =  Left a | Right b   deriving (Eq, Ord, Read, Show)
 
 -- | Case analysis for the 'Either' type.
 -- If the value is @'Left' a@, apply the first function to @a@;
@@ -50,6 +58,8 @@ either f _ (Left x)     =  f x
 either _ g (Right y)    =  g y
 #endif  /* __GLASGOW_HASKELL__ */
 
+INSTANCE_TYPEABLE2(Either,eitherTc,"Either")
+
 -- | Extracts from a list of 'Either' all the 'Left' elements
 -- All the 'Left' elements are extracted in order.
 
@@ -70,8 +80,8 @@ 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)
 
 {-
 {--------------------------------------------------------------------