treewide: (*.->m)empty

These were the last ones.

`mempty` infers everywhere.

Author: Anton-Latukha

main/Main.hs

@@ -105,7 +105,7 @@ main =
                 (\ ty  -> liftIO $ putStrLn $ "Type of expression: " <> PS.ppShow
                   (fromJust $ Map.lookup "it" $ Env.types ty)
                 )
-                (HM.inferTop Env.empty [("it", stripAnnotation expr')])
+                (HM.inferTop mempty [("it", stripAnnotation expr')])
 
                 -- liftIO $ putStrLn $ runST $
                 --     runLintM opts . renderSymbolic =<< lint opts expr

main/Repl.hs

@@ -208,7 +208,7 @@ exec update source = do
       -- import qualified Nix.Type.Env                  as Env
       -- import           Nix.Type.Infer
       --
-      -- let tyctx' = inferTop Env.empty [("repl", stripAnnotation expr)]
+      -- let tyctx' = inferTop mempty [("repl", stripAnnotation expr)]
       -- liftIO $ print tyctx'
 
       mVal <- lift $ lift $ try $ pushScope (replCtx st) (evalExprLoc expr)

src/Nix/Builtins.hs

@@ -959,7 +959,7 @@ genericClosureNix c =
         ss <- fromValue @[NValue t f m] =<< demand startSet
         op <- demand operator
 
-        toValue @[NValue t f m] =<< snd <$> go op S.empty ss
+        toValue @[NValue t f m] =<< snd <$> go op mempty ss
  where
   go
     :: NValue t f m

src/Nix/Effects.hs

@@ -449,4 +449,4 @@ addPath p =
     =<< addToStore (toText $ takeFileName p) p True False
 
 toFile_ :: (Framed e m, MonadStore m) => FilePath -> String -> m StorePath
-toFile_ p contents = addTextToStore (toText p) (toText contents) HS.empty False
+toFile_ p contents = addTextToStore (toText p) (toText contents) mempty False