Keep track of free type variables in the interactive bindings

[ghc-hetmet.git] / compiler / main / HscTypes.lhs

diff --git a/compiler/main/HscTypes.lhs b/compiler/main/HscTypes.lhs
index 99495fe..04f2b7c 100644 (file)
--- a/compiler/main/HscTypes.lhs
+++ b/compiler/main/HscTypes.lhs
@@ -85,6 +85,7 @@ import InstEnv                ( InstEnv, Instance )
 import FamInstEnv      ( FamInstEnv, FamInst )
 import Rules           ( RuleBase )
 import CoreSyn         ( CoreBind )
+import VarSet
 import Id              ( Id, isImplicitId )
 import Type            ( TyThing(..) )
 
@@ -614,18 +615,27 @@ data InteractiveContext
        ic_rn_gbl_env :: GlobalRdrEnv,  -- The cached GlobalRdrEnv, built from
                                        -- ic_toplev_scope and ic_exports
 
-       ic_rn_local_env :: LocalRdrEnv, -- Lexical context for variables bound
-                                       -- during interaction
-
-       ic_type_env :: TypeEnv          -- Ditto for types
+       ic_type_env :: TypeEnv,         -- Type env for names bound during
+                                        -- interaction.  NB. the names from
+                                        -- these Ids are used to populate
+                                        -- the LocalRdrEnv used during
+                                        -- typechecking of a statement, so
+                                        -- there should be no duplicate
+                                        -- names in here.
+
+        ic_tyvars :: TyVarSet           -- skolem type variables free in
+                                        -- ic_type_env.  These arise at
+                                        -- breakpoints in a polymorphic 
+                                        -- context, where we have only partial
+                                        -- type information.
     }
 
 emptyInteractiveContext
   = InteractiveContext { ic_toplev_scope = [],
                         ic_exports = [],
                         ic_rn_gbl_env = emptyGlobalRdrEnv,
-                        ic_rn_local_env = emptyLocalRdrEnv,
-                        ic_type_env = emptyTypeEnv }
+                        ic_type_env = emptyTypeEnv,
+                         ic_tyvars = emptyVarSet }
 
 icPrintUnqual :: InteractiveContext -> PrintUnqualified
 icPrintUnqual ictxt = mkPrintUnqualified (ic_rn_gbl_env ictxt)