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

diff --git a/compiler/types/Coercion.lhs b/compiler/types/Coercion.lhs
index 6417e41..05f1601 100644 (file)
--- a/compiler/types/Coercion.lhs
+++ b/compiler/types/Coercion.lhs
@@ -12,6 +12,13 @@ The coercion kind constructor is a special TyCon that must always be saturated
   typeKind (symCoercion type) :: TyConApp CoercionTyCon{...} [type, type]
 
 \begin{code}
+{-# OPTIONS -w #-}
+-- 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/Commentary/CodingStyle#Warnings
+-- for details
+
 module Coercion (
         Coercion,
  
@@ -364,7 +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"
+              $$
+              ppr r1 <+> text "=/=" <+> ppr a2)
         (a1, r2)
       where
         (a1, r1) = coercionKind co1
@@ -394,6 +404,9 @@ splitCoercionKindOf co
   , Just (ty_fun1, ty_arg1) <- splitAppTy_maybe ty1
   , Just (ty_fun2, ty_arg2) <- splitAppTy_maybe ty2
   = ((ty_fun1, ty_fun2),(ty_arg1, ty_arg2))
+splitCoercionKindOf co 
+  = pprPanic "Coercion.splitCoercionKindOf" 
+             (ppr co $$ ppr (coercionKindPredTy co))
 
 instCoercionTyCon 
   =  mkCoercionTyCon instCoercionTyConName 2 instCoercionKind
@@ -518,9 +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))