Another round of External Core fixes

[ghc-hetmet.git] / compiler / typecheck / TcDeriv.lhs

diff --git a/compiler/typecheck/TcDeriv.lhs b/compiler/typecheck/TcDeriv.lhs
index e79318b..2edd836 100644 (file)
--- a/compiler/typecheck/TcDeriv.lhs
+++ b/compiler/typecheck/TcDeriv.lhs
@@ -46,6 +46,7 @@ import SrcLoc
 import Util
 import ListSetOps
 import Outputable
+import FastString
 import Bag
 \end{code}
 
@@ -265,7 +266,7 @@ tcDeriving  :: [LTyClDecl Name]  -- All type constructors
                    HsValBinds Name)    -- Extra generated top-level bindings
 
 tcDeriving tycl_decls inst_decls deriv_decls
-  = recoverM (returnM ([], emptyValBindsOut)) $
+  = recoverM (return ([], emptyValBindsOut)) $
     do {       -- Fish the "deriving"-related information out of the TcEnv
                -- And make the necessary "equations".
        ; early_specs <- makeDerivSpecs tycl_decls inst_decls deriv_decls
@@ -286,8 +287,8 @@ tcDeriving tycl_decls inst_decls deriv_decls
        ; let inst_info = insts1 ++ insts2
 
        ; dflags <- getDOpts
-       ; ioToTcRn (dumpIfSet_dyn dflags Opt_D_dump_deriv "Derived instances" 
-                  (ddump_deriving inst_info rn_binds))
+       ; liftIO (dumpIfSet_dyn dflags Opt_D_dump_deriv "Derived instances"
+                (ddump_deriving inst_info rn_binds))
 
        ; return (inst_info, rn_binds) }
   where
@@ -798,10 +799,10 @@ mkNewTypeEqn orig mayDeriveDataTypeable newtype_deriving tvs
                -- Want to drop 1 arg from (T s a) and (ST s a)
                -- to get       instance Monad (ST s) => Monad (T s)
 
-       -- Note [newtype representation]
-       -- Need newTyConRhs *not* newTyConRep to get the representation 
-       -- type, because the latter looks through all intermediate newtypes
-       -- For example
+       -- Note [Newtype representation]
+       -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+       -- Need newTyConRhs (*not* a recursive representation finder) 
+       -- to get the representation type. For example
        --      newtype B = MkB Int
        --      newtype A = MkA B deriving( Num )
        -- We want the Num instance of B, *not* the Num instance of Int,