X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Ftypes%2FType.lhs;h=d80bd52c0ee6cb948ca508af51a93bb04aceebe4;hp=716307966c219ad4e7abdf880f28f59fccf5221f;hb=c4ec8f2a77894af1c6160c4e8ad5625ab62f0bea;hpb=f38871fdd92e466cbbc7eb08e226c4213bcbd7d6

diff --git a/compiler/types/Type.lhs b/compiler/types/Type.lhs
index 7163079..d80bd52 100644
--- a/compiler/types/Type.lhs
+++ b/compiler/types/Type.lhs
@@ -128,7 +128,7 @@ module Type (
         isEmptyTvSubst,
 
 	-- ** Performing substitution on types
-	substTy, substTys, substTyWith, substTheta, 
+	substTy, substTys, substTyWith, substTysWith, substTheta, 
 	substPred, substTyVar, substTyVars, substTyVarBndr, deShadowTy, lookupTyVar,
 
 	-- * Pretty-printing
@@ -1514,6 +1514,12 @@ substTyWith :: [TyVar] -> [Type] -> Type -> Type
 substTyWith tvs tys = ASSERT( length tvs == length tys )
 		      substTy (zipOpenTvSubst tvs tys)
 
+-- | Type substitution making use of an 'TvSubst' that
+-- is assumed to be open, see 'zipOpenTvSubst'
+substTysWith :: [TyVar] -> [Type] -> [Type] -> [Type]
+substTysWith tvs tys = ASSERT( length tvs == length tys )
+		       substTys (zipOpenTvSubst tvs tys)
+
 -- | Substitute within a 'Type'
 substTy :: TvSubst -> Type  -> Type
 substTy subst ty | isEmptyTvSubst subst = ty