[project @ 1999-05-18 15:03:54 by simonpj]

[ghc-hetmet.git] / ghc / compiler / typecheck / TcType.lhs

diff --git a/ghc/compiler/typecheck/TcType.lhs b/ghc/compiler/typecheck/TcType.lhs
index 48d58fe..72d4eb7 100644 (file)
--- a/ghc/compiler/typecheck/TcType.lhs
+++ b/ghc/compiler/typecheck/TcType.lhs
@@ -56,9 +56,9 @@ import Type           ( Type(..), Kind, ThetaType, TyNote(..),
                          mkAppTy, mkTyConApp,
                          splitDictTy_maybe, splitForAllTys, isNotUsgTy,
                          isTyVarTy, mkTyVarTy, mkTyVarTys, 
-                         fullSubstTy, substTopTy, 
                          typeCon, openTypeKind, boxedTypeKind, boxedKind, superKind, superBoxity
                        )
+import Subst           ( Subst, mkTopTyVarSubst, substTy )
 import TyCon           ( tyConKind, mkPrimTyCon )
 import PrimRep         ( PrimRep(VoidRep) )
 import VarEnv
@@ -170,14 +170,17 @@ Instantiating a bunch of type variables
 
 \begin{code}
 tcInstTyVars :: [TyVar] 
-            -> NF_TcM s ([TcTyVar], [TcType], TyVarEnv TcType)
+            -> NF_TcM s ([TcTyVar], [TcType], Subst)
 
 tcInstTyVars tyvars
   = mapNF_Tc tcInstTyVar tyvars        `thenNF_Tc` \ tc_tyvars ->
     let
        tys = mkTyVarTys tc_tyvars
     in
-    returnNF_Tc (tc_tyvars, tys, zipVarEnv tyvars tys)
+    returnNF_Tc (tc_tyvars, tys, mkTopTyVarSubst tyvars tys)
+               -- Since the tyvars are freshly made,
+               -- they cannot possibly be captured by
+               -- any existing for-alls.  Hence mkTopTyVarSubst
 
 tcInstTyVar tyvar
   = tcGetUnique                `thenNF_Tc` \ uniq ->
@@ -229,10 +232,7 @@ tcInstTcType ty
   = case splitForAllTys ty of
        ([], _)       -> returnNF_Tc ([], ty)   -- Nothing to do
        (tyvars, rho) -> tcInstTyVars tyvars            `thenNF_Tc` \ (tyvars', _, tenv)  ->
-                        returnNF_Tc (tyvars', fullSubstTy tenv emptyVarSet rho)
-                                       -- Since the tyvars are freshly made,
-                                       -- they cannot possibly be captured by
-                                       -- any existing for-alls.  Hence emptyVarSet
+                        returnNF_Tc (tyvars', substTy tenv rho)
 \end{code}