X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Fspecialise%2FRules.lhs;h=24c400491ce85b5d1c12281bb18311cdea097b65;hb=92e7ecbcc393caab7f0d8883a51cbfca42767cb1;hp=26a499bfebc8a1f00c4264eb2f213d38043742de;hpb=262c142b90c94ca1aa577c950a6ceae1f255e2d6;p=ghc-hetmet.git

diff --git a/compiler/specialise/Rules.lhs b/compiler/specialise/Rules.lhs
index 26a499b..24c4004 100644
--- a/compiler/specialise/Rules.lhs
+++ b/compiler/specialise/Rules.lhs
@@ -4,6 +4,13 @@
 \section[CoreRules]{Transformation rules}
 
 \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 Rules (
 	RuleBase, emptyRuleBase, mkRuleBase, extendRuleBaseList, 
 	unionRuleBase, pprRuleBase, ruleCheckProgram,
@@ -588,11 +595,8 @@ match menv subst (Type ty1) (Type ty2)
   = match_ty menv subst ty1 ty2
 
 match menv subst (Cast e1 co1) (Cast e2 co2)
-  | (from1, to1) <- coercionKind co1
-  , (from2, to2) <- coercionKind co2
-  = do	{ subst1 <- match_ty menv subst  to1   to2
-	; subst2 <- match_ty menv subst1 from1 from2
-	; match menv subst2 e1 e2 }
+  = do	{ subst1 <- match_ty menv subst co1 co2
+	; match menv subst1 e1 e2 }
 
 {-	REMOVING OLD CODE: I think that the above handling for let is 
 			   better than the stuff here, which looks 
@@ -639,6 +643,8 @@ match_var menv subst@(tv_subst, id_subst, binds) v1 e2
 
 		| otherwise	-- No renaming to do on e2, because no free var
 				-- of e2 is in the rnEnvR of the envt
+		-- Note [Matching variable types]
+		-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 		-- However, we must match the *types*; e.g.
 		--   forall (c::Char->Int) (x::Char). 
 		--	f (c x) = "RULE FIRED"