X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Ftypes%2FTypeRep.lhs;h=69ee4194396062d2216c2406739ef155c0d2718d;hb=14ddfba2df68917958afb54142bb609c66fa2110;hp=2fe5954a15c44c2c9c71c0ef53e1903304d41acc;hpb=ad94d40948668032189ad22a0ad741ac1f645f50;p=ghc-hetmet.git

diff --git a/compiler/types/TypeRep.lhs b/compiler/types/TypeRep.lhs
index 2fe5954..69ee419 100644
--- a/compiler/types/TypeRep.lhs
+++ b/compiler/types/TypeRep.lhs
@@ -9,7 +9,7 @@
 -- The above warning supression flag is a temporary kludge.
 -- While working on this module you are encouraged to remove it and fix
 -- any warnings in the module. See
---     http://hackage.haskell.org/trac/ghc/wiki/CodingStyle#Warnings
+--     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
 -- for details
 
 module TypeRep (
@@ -23,7 +23,7 @@ module TypeRep (
 
 	-- Pretty-printing
 	pprType, pprParendType, pprTypeApp,
-	pprTyThingCategory, 
+	pprTyThing, pprTyThingCategory, 
 	pprPred, pprTheta, pprForAll, pprThetaArrow, pprClassPred,
 
 	-- Kinds
@@ -31,6 +31,7 @@ module TypeRep (
         argTypeKind, ubxTupleKind,
 	isLiftedTypeKindCon, isLiftedTypeKind,
 	mkArrowKind, mkArrowKinds, isCoercionKind,
+  	coVarPred,
 
         -- Kind constructors...
         liftedTypeKindTyCon, openTypeKindTyCon, unliftedTypeKindTyCon,
@@ -292,8 +293,11 @@ data TyThing = AnId     Id
 	     | ATyCon   TyCon
 	     | AClass   Class
 
-instance Outputable TyThing where
-  ppr thing = pprTyThingCategory thing <+> quotes (ppr (getName thing))
+instance Outputable TyThing where 
+  ppr = pprTyThing
+
+pprTyThing :: TyThing -> SDoc
+pprTyThing thing = pprTyThingCategory thing <+> quotes (ppr (getName thing))
 
 pprTyThingCategory :: TyThing -> SDoc
 pprTyThingCategory (ATyCon _) 	= ptext SLIT("Type constructor")
@@ -409,6 +413,13 @@ isCoercionKind :: Kind -> Bool
 isCoercionKind (NoteTy _ k)         = isCoercionKind k
 isCoercionKind (PredTy (EqPred {})) = True
 isCoercionKind other		    = False
+
+coVarPred :: CoVar -> PredType
+coVarPred tv
+  = ASSERT( isCoVar tv )
+    case tyVarKind tv of
+	PredTy eq -> eq		-- There shouldn't even be a NoteTy in the way
+	other	  -> pprPanic "coVarPred" (ppr tv $$ ppr other)
 \end{code}
 
 
@@ -481,7 +492,7 @@ pprParendKind = pprParendType
 ppr_type :: Prec -> Type -> SDoc
 ppr_type p (TyVarTy tv)       = ppr tv
 ppr_type p (PredTy pred)      = ifPprDebug (ptext SLIT("<pred>")) <> (ppr pred)
-ppr_type p (NoteTy other ty2) = ppr_type p ty2
+ppr_type p (NoteTy other ty2) = ifPprDebug (ptext SLIT("<note>")) <> ppr_type p ty2
 ppr_type p (TyConApp tc tys)  = ppr_tc_app p tc tys
 
 ppr_type p (AppTy t1 t2) = maybeParen p TyConPrec $
@@ -506,15 +517,22 @@ ppr_forall_type p ty
     (tvs,  rho) = split1 [] ty
     (ctxt, tau) = split2 [] rho
 
-    split1 tvs (ForAllTy tv ty) = split1 (tv:tvs) ty
-    split1 tvs (NoteTy _ ty)    = split1 tvs ty
-    split1 tvs ty		= (reverse tvs, ty)
+    -- We need to be extra careful here as equality constraints will occur as
+    -- type variables with an equality kind.  So, while collecting quantified
+    -- variables, we separate the coercion variables out and turn them into
+    -- equality predicates.
+    split1 tvs (ForAllTy tv ty) 
+      | not (isCoVar tv)     = split1 (tv:tvs) ty
+    split1 tvs (NoteTy _ ty) = split1 tvs ty
+    split1 tvs ty	     = (reverse tvs, ty)
  
     split2 ps (NoteTy _ arg 	-- Rather a disgusting case
-	       `FunTy` res) 	      = split2 ps (arg `FunTy` res)
-    split2 ps (PredTy p `FunTy` ty)   = split2 (p:ps) ty
-    split2 ps (NoteTy _ ty) 	      = split2 ps ty
-    split2 ps ty		      = (reverse ps, ty)
+	       `FunTy` res) 	    = split2 ps (arg `FunTy` res)
+    split2 ps (PredTy p `FunTy` ty) = split2 (p:ps) ty
+    split2 ps (ForAllTy tv ty) 
+	| isCoVar tv		    = split2 (coVarPred tv : ps) ty
+    split2 ps (NoteTy _ ty) 	    = split2 ps ty
+    split2 ps ty		    = (reverse ps, ty)
 
 ppr_tc_app :: Prec -> TyCon -> [Type] -> SDoc
 ppr_tc_app p tc []