[project @ 2001-05-16 12:49:59 by simonmar]

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

diff --git a/ghc/compiler/typecheck/TcExpr.lhs b/ghc/compiler/typecheck/TcExpr.lhs
index ebc25af..07c3374 100644 (file)
--- a/ghc/compiler/typecheck/TcExpr.lhs
+++ b/ghc/compiler/typecheck/TcExpr.lhs
@@ -629,7 +629,10 @@ Implicit Parameter bindings.
 tcMonoExpr (HsWith expr binds) res_ty
   = tcMonoExpr expr res_ty                     `thenTc` \ (expr', expr_lie) ->
     mapAndUnzipTc tcIPBind binds               `thenTc` \ (pairs, bind_lies) ->
-    tcSimplifyIPs (map fst binds) expr_lie     `thenTc` \ (expr_lie', dict_binds) ->
+
+       -- If the binding binds ?x = E, we  must now 
+       -- discharge any ?x constraints in expr_lie
+    tcSimplifyIPs (map fst pairs) expr_lie     `thenTc` \ (expr_lie', dict_binds) ->
     let
        binds' = [(instToId ip, rhs) | (ip,rhs) <- pairs]
        expr'' = HsLet (mkMonoBind dict_binds [] Recursive) expr'