Big tidy-up of deriving code

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

diff --git a/compiler/types/Type.lhs b/compiler/types/Type.lhs
index cdc54a1..d81278a 100644 (file)
--- a/compiler/types/Type.lhs
+++ b/compiler/types/Type.lhs
@@ -92,7 +92,7 @@ module Type (
 
        -- Performing substitution on types
        substTy, substTys, substTyWith, substTheta, 
-       substPred, substTyVar, substTyVarBndr, deShadowTy, lookupTyVar,
+       substPred, substTyVar, substTyVars, substTyVarBndr, deShadowTy, lookupTyVar,
 
        -- Pretty-printing
        pprType, pprParendType, pprTyThingCategory, pprForAll,
@@ -411,7 +411,6 @@ splitNewTyConApp_maybe other              = Nothing
 newTyConInstRhs :: TyCon -> [Type] -> Type
 newTyConInstRhs tycon tys =
     let (tvs, ty) = newTyConRhs tycon in substTyWith tvs tys ty
-
 \end{code}
 
 
@@ -1313,6 +1312,9 @@ substTyVar subst@(TvSubst in_scope env) tv
                Just ty -> ty   -- See Note [Apply Once]
     } 
 
+substTyVars :: TvSubst -> [TyVar] -> [Type]
+substTyVars subst tvs = map (substTyVar subst) tvs
+
 lookupTyVar :: TvSubst -> TyVar  -> Maybe Type
        -- See Note [Extending the TvSubst]
 lookupTyVar (TvSubst in_scope env) tv = lookupVarEnv env tv