[commit: array] master: For GHC, implement the Typeable.hs macros using standalone deriving (a2e657f)

[Ian Lynagh]

Repository : ssh://darcs.haskell.org//srv/darcs/packages/array

On branch  : master

http://hackage.haskell.org/trac/ghc/changeset/a2e657fb896bd03893590f1df08f2dc57de9a689

>---------------------------------------------------------------

commit a2e657fb896bd03893590f1df08f2dc57de9a689
Author: Ian Lynagh <igloo at earth.li>
Date:   Sun Apr 24 19:43:30 2011 +0100

    For GHC, implement the Typeable.hs macros using standalone deriving
    
    As well as being more pleasant, this fixes #1841:
        Data.Typeable: Instances of basic types don't provide qualified
        strings to mkTyCon

>---------------------------------------------------------------

 array.cabal        |    2 ++
 include/Typeable.h |   28 +++++++++-------------------
 2 files changed, 11 insertions(+), 19 deletions(-)

diff --git a/array.cabal b/array.cabal
index 8352b0e..e3fb91d 100644
--- a/array.cabal
+++ b/array.cabal
@@ -40,6 +40,8 @@ library
       TypeSynonymInstances
   if impl(ghc)
     extensions:
+      DeriveDataTypeable,
+      StandaloneDeriving,
       Rank2Types,
       MagicHash,
       UnboxedTuples,
diff --git a/include/Typeable.h b/include/Typeable.h
index 649d6f3..91fbcdd 100644
--- a/include/Typeable.h
+++ b/include/Typeable.h
@@ -14,32 +14,22 @@
 #ifndef TYPEABLE_H
 #define TYPEABLE_H
 
-#define INSTANCE_TYPEABLE0(tycon,tcname,str) \
-tcname :: TyCon; \
-tcname = mkTyCon str; \
-instance Typeable tycon where { typeOf _ = mkTyConApp tcname [] }
-
 #ifdef __GLASGOW_HASKELL__
 
---  // For GHC, the extra instances follow from general instance declarations
---  // defined in Data.Typeable.
+--  // For GHC, we can use DeriveDataTypeable + StandaloneDeriving to
+--  // generate the instances.
 
-#define INSTANCE_TYPEABLE1(tycon,tcname,str) \
-tcname :: TyCon; \
-tcname = mkTyCon str; \
-instance Typeable1 tycon where { typeOf1 _ = mkTyConApp tcname [] }
+#define INSTANCE_TYPEABLE0(tycon,tcname,str) deriving instance Typeable tycon
+#define INSTANCE_TYPEABLE1(tycon,tcname,str) deriving instance Typeable1 tycon
+#define INSTANCE_TYPEABLE2(tycon,tcname,str) deriving instance Typeable2 tycon
+#define INSTANCE_TYPEABLE3(tycon,tcname,str) deriving instance Typeable3 tycon
 
-#define INSTANCE_TYPEABLE2(tycon,tcname,str) \
-tcname :: TyCon; \
-tcname = mkTyCon str; \
-instance Typeable2 tycon where { typeOf2 _ = mkTyConApp tcname [] }
+#else /* !__GLASGOW_HASKELL__ */
 
-#define INSTANCE_TYPEABLE3(tycon,tcname,str) \
+#define INSTANCE_TYPEABLE0(tycon,tcname,str) \
 tcname :: TyCon; \
 tcname = mkTyCon str; \
-instance Typeable3 tycon where { typeOf3 _ = mkTyConApp tcname [] }
-
-#else /* !__GLASGOW_HASKELL__ */
+instance Typeable tycon where { typeOf _ = mkTyConApp tcname [] }
 
 #define INSTANCE_TYPEABLE1(tycon,tcname,str) \
 tcname = mkTyCon str; \