X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=Data%2FEither.hs;h=fd6651f4cce86ff02451f1803c2b1d71174e209b;hb=748003827970cfc57cb26db256b72d16e504bb37;hp=cb71eaa8d5c5ec4c1896a7fcd311e17b3ab02349;hpb=82d74b928620a26c07351e9b89f5cf0106e3efac;p=ghc-base.git

diff --git a/Data/Either.hs b/Data/Either.hs
index cb71eaa..fd6651f 100644
--- a/Data/Either.hs
+++ b/Data/Either.hs
@@ -21,10 +21,17 @@ 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 +47,7 @@ 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 +57,8 @@ 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 +79,8 @@ 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)
 
 {-
 {--------------------------------------------------------------------