X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=GHC%2FShow.lhs;h=bbfe45849b56f0affa5fc0e59817993e77cf8997;hb=HEAD;hp=2c673a82c876bd99ebbcafdd7e429500dc6c844f;hpb=5ba076a7ebba87a34293dca92d8b3d8ea0dd9648;p=ghc-base.git

diff --git a/GHC/Show.lhs b/GHC/Show.lhs
index 2c673a8..bbfe458 100644
--- a/GHC/Show.lhs
+++ b/GHC/Show.lhs
@@ -1,7 +1,7 @@
 \begin{code}
-{-# LANGUAGE BangPatterns #-}
-{-# OPTIONS_GHC -XNoImplicitPrelude #-}
+{-# LANGUAGE NoImplicitPrelude, BangPatterns, MagicHash, StandaloneDeriving #-}
 {-# OPTIONS_HADDOCK hide #-}
+
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  GHC.Show
@@ -38,6 +38,8 @@ module GHC.Show
 import GHC.Base
 import Data.Maybe
 import GHC.List ((!!), foldr1, break)
+-- For defining instances for the generic deriving mechanism
+import GHC.Generics (Arity(..), Associativity(..), Fixity(..))
 \end{code}
 
 
@@ -429,3 +431,10 @@ itos n# cs
                       itos' (x# `quotInt#` 10#) (C# c# : cs') }
 \end{code}
 
+Instances for types of the generic deriving mechanism.
+
+\begin{code}
+deriving instance Show Arity
+deriving instance Show Associativity
+deriving instance Show Fixity
+\end{code}