- let Just reconstructedType = termType term
- new_type = mostSpecificType (idType id) reconstructedType
- return . Just $ setIdType id new_type
-
- updateIds :: Session -> [Id] -> IO ()
- updateIds (Session ref) new_ids = do
- hsc_env <- readIORef ref
- let ictxt = hsc_IC hsc_env
- type_env = ic_type_env ictxt
- filtered_type_env = delListFromNameEnv type_env (map idName new_ids)
- new_type_env = extendTypeEnvWithIds filtered_type_env new_ids
- new_ic = ictxt {ic_type_env = new_type_env }
- writeIORef ref (hsc_env {hsc_IC = new_ic })
-
-isMoreSpecificThan :: Type -> Type -> Bool
-ty `isMoreSpecificThan` ty1
- | Just subst <- tcUnifyTys bindOnlyTy1 [repType' ty] [repType' ty1]
- , substFiltered <- filter (not.isTyVarTy) . varEnvElts . getTvSubstEnv $ subst
- , not . null $ substFiltered
- , all (flip notElemTvSubst subst) ty_vars
- = True
- | otherwise = False
- where bindOnlyTy1 tyv | tyv `elem` ty_vars = AvoidMe
- | otherwise = BindMe
- ty_vars = varSetElems$ tyVarsOfType ty
-
-mostSpecificType ty1 ty2 | ty1 `isMoreSpecificThan` ty2 = ty1
- | otherwise = ty2
+ -- Then, we extract a substitution,
+ -- mapping the old tyvars to the reconstructed types.
+ let Just reconstructed_type = termType term
+ -- tcUnifyTys doesn't look through forall's, so we drop them from
+ -- the original type, instead of sigma-typing the reconstructed type
+ mb_subst = tcUnifyTys (const BindMe) [dropForAlls$ idType id]
+ [reconstructed_type]
+ ASSERT2 (isJust mb_subst, ppr reconstructed_type $$ (ppr$ idType id))
+ return mb_subst
+
+ applySubstToEnv :: Session -> TvSubst -> IO ()
+ applySubstToEnv cms subst | isEmptyTvSubst subst = return ()
+ applySubstToEnv cms@(Session ref) subst = do
+ hsc_env <- readIORef ref
+ inScope <- GHC.getBindings cms
+ let ictxt = hsc_IC hsc_env
+ type_env = ic_type_env ictxt
+ ids = typeEnvIds type_env
+ ids' = map (\id -> id `setIdType` substTy subst (idType id)) ids
+ type_env'= extendTypeEnvWithIds type_env ids'
+ ictxt' = ictxt { ic_type_env = type_env' }
+ writeIORef ref (hsc_env {hsc_IC = ictxt'})