From 31c195c9144131de63f5093e4ac714f33fc68ab1 Mon Sep 17 00:00:00 2001
From: simonpj <unknown>
Date: Thu, 25 Jan 2001 17:09:46 +0000
Subject: [PATCH] [project @ 2001-01-25 17:09:46 by simonpj] Add elemSubstEnv

---
 ghc/compiler/basicTypes/VarEnv.lhs |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/ghc/compiler/basicTypes/VarEnv.lhs b/ghc/compiler/basicTypes/VarEnv.lhs
index 646d5fa..393a384 100644
--- a/ghc/compiler/basicTypes/VarEnv.lhs
+++ b/ghc/compiler/basicTypes/VarEnv.lhs
@@ -21,7 +21,7 @@ module VarEnv (
 
 	-- SubstEnvs
 	SubstEnv, TyVarSubstEnv, SubstResult(..),
-	emptySubstEnv, substEnvEnv,
+	emptySubstEnv, substEnvEnv, elemSubstEnv,
 	mkSubstEnv, lookupSubstEnv, extendSubstEnv, extendSubstEnvList,
 	delSubstEnv, delSubstEnvList, noTypeSubst, isEmptySubstEnv
     ) where
@@ -93,6 +93,9 @@ isEmptySubstEnv (SE s _) = isEmptyVarEnv s
 lookupSubstEnv :: SubstEnv -> Var -> Maybe SubstResult
 lookupSubstEnv (SE s _) v = lookupVarEnv s v
 
+elemSubstEnv :: Var -> SubstEnv -> Bool
+elemSubstEnv v (SE s _) = elemVarEnv v s
+
 extendSubstEnv :: SubstEnv -> Var -> SubstResult -> SubstEnv
 extendSubstEnv (SE s nt) v r = SE (extendVarEnv s v r) (noTys r nt)
 
-- 
1.7.10.4