ghc-mod/core/GhcMod/Monad/Env.hs

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-- ghc-mod: Happy Haskell Hacking
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-- 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 GhcMod.Monad.Env where
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import GhcMod.Types
import GhcMod.Monad.Newtypes
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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)