This goes with the patch for #1839, #1463

[ghc-hetmet.git] / compiler / types / Coercion.lhs

diff --git a/compiler/types/Coercion.lhs b/compiler/types/Coercion.lhs
index fa4a6b7..05f1601 100644 (file)
--- a/compiler/types/Coercion.lhs
+++ b/compiler/types/Coercion.lhs
@@ -371,7 +371,10 @@ transCoercionTyCon =
   where
     composeCoercionKindsOf (co1:co2:rest)
       = ASSERT( null rest )
-        WARN( not (r1 `coreEqType` a2), text "Strange! Type mismatch in trans coercion, probably a bug")
+        WARN( not (r1 `coreEqType` a2), 
+              text "Strange! Type mismatch in trans coercion, probably a bug"
+              $$
+              ppr r1 <+> text "=/=" <+> ppr a2)
         (a1, r2)
       where
         (a1, r1) = coercionKind co1
@@ -401,6 +404,9 @@ splitCoercionKindOf co
   , Just (ty_fun1, ty_arg1) <- splitAppTy_maybe ty1
   , Just (ty_fun2, ty_arg2) <- splitAppTy_maybe ty2
   = ((ty_fun1, ty_fun2),(ty_arg1, ty_arg2))
+splitCoercionKindOf co 
+  = pprPanic "Coercion.splitCoercionKindOf" 
+             (ppr co $$ ppr (coercionKindPredTy co))
 
 instCoercionTyCon 
   =  mkCoercionTyCon instCoercionTyConName 2 instCoercionKind
@@ -525,9 +531,9 @@ mkForAllTyCoI :: TyVar -> CoercionI -> CoercionI
 mkForAllTyCoI _ IdCo = IdCo
 mkForAllTyCoI tv (ACo co) = ACo $ ForAllTy tv co
 
+fromACo :: CoercionI -> Coercion
 fromACo (ACo co) = co
 
-
 mkClassPPredCoI :: Class -> [Type] -> [CoercionI] -> CoercionI
 -- mkClassPPredCoI cls tys cois = coi
 --    coi : PredTy (cls tys) ~ predTy (cls (tys `cast` cois))