X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Ftypecheck%2FTcMType.lhs;h=30917eff83083f91c82f4a7a5dd0495494e01c03;hb=9e5f0a0f6848dd8234a83d8ff514365aa4717eea;hp=a6a96342ee020872201c668ba2e1b1f4eb36df07;hpb=2eb105009654588b2130997509645841800681b9;p=ghc-hetmet.git

diff --git a/compiler/typecheck/TcMType.lhs b/compiler/typecheck/TcMType.lhs
index a6a9634..30917ef 100644
--- a/compiler/typecheck/TcMType.lhs
+++ b/compiler/typecheck/TcMType.lhs
@@ -222,7 +222,6 @@ checkTauTvUpdate orig_tv orig_ty
 	| isSynTyCon tc  = go_syn tc tys
 	| otherwise	 = do { tys' <- mapM go tys
                               ; return $ occurs (TyConApp tc) tys' }
-    go (NoteTy _ ty2) 	 = go ty2	-- Discard free-tyvar annotations
     go (PredTy p)	 = do { p' <- go_pred p
                               ; return $ occurs1 PredTy p' }
     go (FunTy arg res)   = do { arg' <- go arg
@@ -507,14 +506,12 @@ isFilledMetaTyVar tv
   | otherwise = return False
 
 writeMetaTyVar :: TcTyVar -> TcType -> TcM ()
-#ifndef DEBUG
-writeMetaTyVar tyvar ty = writeMutVar (metaTvRef tyvar) (Indirect ty)
-#else
+writeMetaTyVar tyvar ty
+  | not debugIsOn = writeMutVar (metaTvRef tyvar) (Indirect ty)
 writeMetaTyVar tyvar ty
   | not (isMetaTyVar tyvar)
   = pprTrace "writeMetaTyVar" (ppr tyvar) $
     return ()
-
   | otherwise
   = ASSERT( isMetaTyVar tyvar )
     -- TOM: It should also work for coercions
@@ -524,7 +521,6 @@ writeMetaTyVar tyvar ty
   where
     k1 = tyVarKind tyvar
     k2 = typeKind ty
-#endif
 \end{code}
 
 
@@ -888,8 +884,6 @@ zonkType :: (TcTyVar -> TcM Type) 	-- What to do with unbound mutable type varia
 zonkType unbound_var_fn ty
   = go ty
   where
-    go (NoteTy _ ty2) 	 = go ty2	-- Discard free-tyvar annotations
-
     go (TyConApp tc tys) = do tys' <- mapM go tys
                               return (TyConApp tc tys')
 
@@ -1112,9 +1106,6 @@ check_type rank ubx_tup (AppTy ty1 ty2)
   = do	{ check_arg_type rank ty1
 	; check_arg_type rank ty2 }
 
-check_type rank ubx_tup (NoteTy other_note ty)
-  = check_type rank ubx_tup ty
-
 check_type rank ubx_tup ty@(TyConApp tc tys)
   | isSynTyCon tc
   = do	{ 	-- Check that the synonym has enough args
@@ -1505,10 +1496,11 @@ check_inst_head dflags clas tys
                 text "where T is not a synonym." $$
                 text "Use -XTypeSynonymInstances if you want to disable this.")
 
-    head_type_args_tyvars_msg = parens (
-                text "All instance types must be of the form (T a1 ... an)" $$
-                text "where a1 ... an are distinct type *variables*" $$
-                text "Use -XFlexibleInstances if you want to disable this.")
+    head_type_args_tyvars_msg = parens (vcat [
+                text "All instance types must be of the form (T a1 ... an)",
+                text "where a1 ... an are type *variables*,",
+                text "and each type variable appears at most once in the instance head.",
+                text "Use -XFlexibleInstances if you want to disable this."])
 
     head_one_type_msg = parens (
                 text "Only one type can be given in an instance head." $$
@@ -1753,7 +1745,6 @@ fvType :: Type -> [TyVar]
 fvType ty | Just exp_ty <- tcView ty = fvType exp_ty
 fvType (TyVarTy tv)        = [tv]
 fvType (TyConApp _ tys)    = fvTypes tys
-fvType (NoteTy _ ty)       = fvType ty
 fvType (PredTy pred)       = fvPred pred
 fvType (FunTy arg res)     = fvType arg ++ fvType res
 fvType (AppTy fun arg)     = fvType fun ++ fvType arg
@@ -1772,7 +1763,6 @@ sizeType :: Type -> Int
 sizeType ty | Just exp_ty <- tcView ty = sizeType exp_ty
 sizeType (TyVarTy _)       = 1
 sizeType (TyConApp _ tys)  = sizeTypes tys + 1
-sizeType (NoteTy _ ty)     = sizeType ty
 sizeType (PredTy pred)     = sizePred pred
 sizeType (FunTy arg res)   = sizeType arg + sizeType res + 1
 sizeType (AppTy fun arg)   = sizeType fun + sizeType arg