From e345c92edb4a2b2f60a9b0adaa68fff76f0d0c4e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Gr=C3=B6ber?= <dxld@darkboxed.org>
Date: Tue, 12 Aug 2014 18:09:31 +0200
Subject: [PATCH] Make GhcModT's MonadState instance pass through

..to the underlying monad
---
 Language/Haskell/GhcMod/Monad.hs  | 29 +++++++++++++++++++----------
 Language/Haskell/GhcMod/Target.hs |  2 +-
 2 files changed, 20 insertions(+), 11 deletions(-)

diff --git a/Language/Haskell/GhcMod/Monad.hs b/Language/Haskell/GhcMod/Monad.hs
index 44e9dd0..6df8380 100644
--- a/Language/Haskell/GhcMod/Monad.hs
+++ b/Language/Haskell/GhcMod/Monad.hs
@@ -30,8 +30,6 @@ module Language.Haskell.GhcMod.Monad (
   , withOptions
   -- ** Exporting convenient modules
   , module Control.Monad.Reader.Class
-  , module Control.Monad.Writer.Class
-  , module Control.Monad.State.Class
   , module Control.Monad.Journal.Class
   ) where
 
@@ -85,10 +83,10 @@ import Control.Monad.Trans.Control (MonadBaseControl(..), StM, liftBaseWith,
 
 import Control.Monad.Trans.Class
 import Control.Monad.Reader.Class
-import Control.Monad.Writer.Class
-import Control.Monad.State.Class
+import Control.Monad.Writer.Class (MonadWriter)
+import Control.Monad.State.Class (MonadState(..))
 
-import Control.Monad.Error (Error(..), MonadError, ErrorT, runErrorT)
+import Control.Monad.Error (MonadError, ErrorT, runErrorT)
 import Control.Monad.Reader (ReaderT, runReaderT)
 import Control.Monad.State.Strict (StateT, runStateT)
 import Control.Monad.Trans.Journal (JournalT, runJournalT)
@@ -155,13 +153,18 @@ newtype GhcModT m a = GhcModT {
 #endif
                , MonadReader GhcModEnv
                , MonadWriter w
-               , MonadState GhcModState
                , MonadError GhcModError
                )
 
 instance MonadTrans GhcModT where
     lift = GhcModT . lift . lift . lift . lift
 
+instance MonadState s m => MonadState s (GhcModT m) where
+    get = GhcModT $ lift $ lift $ lift $ get
+    put = GhcModT . lift . lift . lift . put
+    state = GhcModT . lift . lift . lift . state
+
+
 #if MONADIO_INSTANCES
 instance MonadIO m => MonadIO (StateT s m) where
     liftIO = lift . liftIO
@@ -283,17 +286,23 @@ toGhcModT a = do
 
 ----------------------------------------------------------------
 
+gmsGet :: IOish m => GhcModT m GhcModState
+gmsGet = GhcModT get
+
+gmsPut :: IOish m => GhcModState -> GhcModT m ()
+gmsPut = GhcModT . put
+
 options :: IOish m => GhcModT m Options
 options = gmOptions <$> ask
 
 cradle :: IOish m => GhcModT m Cradle
 cradle = gmCradle <$> ask
 
-getCompilerMode :: (Functor m, MonadState GhcModState m) => m CompilerMode
-getCompilerMode = gmCompilerMode <$> get
+getCompilerMode :: IOish m => GhcModT m CompilerMode
+getCompilerMode = gmCompilerMode <$> gmsGet
 
-setCompilerMode :: MonadState GhcModState m => CompilerMode -> m ()
-setCompilerMode mode = (\s -> put s { gmCompilerMode = mode } ) =<< get
+setCompilerMode :: IOish m => CompilerMode -> GhcModT m ()
+setCompilerMode mode = (\s -> gmsPut s { gmCompilerMode = mode } ) =<< gmsGet
 
 ----------------------------------------------------------------
 
diff --git a/Language/Haskell/GhcMod/Target.hs b/Language/Haskell/GhcMod/Target.hs
index 572388b..1744a72 100644
--- a/Language/Haskell/GhcMod/Target.hs
+++ b/Language/Haskell/GhcMod/Target.hs
@@ -15,7 +15,7 @@ setTargetFiles :: IOish m => [FilePath] -> GhcModT m ()
 setTargetFiles files = do
     targets <- forM files $ \file -> G.guessTarget file Nothing
     G.setTargets targets
-    mode <- gmCompilerMode <$> get
+    mode <- getCompilerMode
     if mode == Intelligent then
         loadTargets Intelligent
       else do