Split L.H.GM.Monad.Types module

Language/Haskell/GhcMod/Monad/Env.hs

@@ -0,0 +1,68 @@
+-- ghc-mod: Making Haskell development *more* fun
+-- Copyright (C) 2015,2016  Daniel Gröber <dxld ÄT darkboxed DOT org>
+--
+-- This program is free software: you can redistribute it and/or modify
+-- it under the terms of the GNU Affero General Public License as published by
+-- the Free Software Foundation, either version 3 of the License, or
+-- (at your option) any later version.
+--
+-- This program is distributed in the hope that it will be useful,
+-- but WITHOUT ANY WARRANTY; without even the implied warranty of
+-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+-- GNU Affero General Public License for more details.
+--
+-- You should have received a copy of the GNU Affero General Public License
+-- along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+{-# LANGUAGE GeneralizedNewtypeDeriving, StandaloneDeriving #-}
+{-# LANGUAGE FlexibleInstances, UndecidableInstances #-}
+
+module Language.Haskell.GhcMod.Monad.Env where
+
+import Language.Haskell.GhcMod.Types
+import Language.Haskell.GhcMod.Monad.Newtypes
+
+import Control.Monad
+import Control.Monad.Trans.Journal (JournalT)
+import Control.Monad.State.Strict (StateT(..))
+import Control.Monad.Error (ErrorT(..))
+import Control.Monad.Reader.Class
+import Control.Monad.Trans.Class (MonadTrans(..))
+import Prelude
+
+class Monad m => GmEnv m where
+    gmeAsk :: m GhcModEnv
+    gmeAsk = gmeReader id
+
+    gmeReader :: (GhcModEnv -> a) -> m a
+    gmeReader f = f `liftM` gmeAsk
+
+    gmeLocal :: (GhcModEnv -> GhcModEnv) -> m a -> m a
+    {-# MINIMAL (gmeAsk | gmeReader), gmeLocal #-}
+
+instance Monad m => GmEnv (GmT m) where
+    gmeAsk = GmT ask
+    gmeReader = GmT . reader
+    gmeLocal f a = GmT $ local f (unGmT a)
+
+instance GmEnv m => GmEnv (GmOutT m) where
+    gmeAsk = lift gmeAsk
+    gmeReader = lift . gmeReader
+    gmeLocal f ma = gmLiftWithInner (\run -> gmeLocal f (run ma))
+
+instance GmEnv m => GmEnv (StateT s m) where
+    gmeAsk = lift gmeAsk
+    gmeReader = lift . gmeReader
+    gmeLocal f ma = gmLiftWithInner (\run -> gmeLocal f (run ma))
+
+instance GmEnv m => GmEnv (JournalT GhcModLog m) where
+    gmeAsk = lift gmeAsk
+    gmeReader = lift . gmeReader
+    gmeLocal f ma = gmLiftWithInner (\run -> gmeLocal f (run ma))
+
+instance GmEnv m => GmEnv (ErrorT GhcModError m) where
+    gmeAsk = lift gmeAsk
+    gmeReader = lift . gmeReader
+    gmeLocal f ma = gmLiftWithInner (\run -> gmeLocal f (run ma))
+
+deriving instance (Monad m, GmEnv (GhcModT m)) => GmEnv (GmlT m)