Add MonadFail constraint for GHC 8.6.1

[lsp-test.git] / src / Language / Haskell / LSP / Test / Session.hs

diff --git a/src/Language/Haskell/LSP/Test/Session.hs b/src/Language/Haskell/LSP/Test/Session.hs
index 5948ed0a818c1aed1b28cbef5b5f463d1b952ce7..28d4eddec1591fbbe190fc825abc5c0c1453a0f5 100644 (file)
--- a/src/Language/Haskell/LSP/Test/Session.hs
+++ b/src/Language/Haskell/LSP/Test/Session.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP               #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
@@ -32,6 +33,9 @@ import Control.Lens hiding (List)
 import Control.Monad
 import Control.Monad.IO.Class
 import Control.Monad.Except
+#if __GLASGOW_HASKELL__ >= 806
+import qualified Control.Monad.Fail as Fail
+#endif
 import Control.Monad.Trans.Reader (ReaderT, runReaderT)
 import qualified Control.Monad.Trans.Reader as Reader (ask)
 import Control.Monad.Trans.State (StateT, runStateT)
@@ -73,7 +77,7 @@ type Session = ParserStateReader FromServerMessage SessionState SessionContext I
 data SessionConfig = SessionConfig
   { messageTimeout :: Int  -- ^ Maximum time to wait for a message in seconds, defaults to 60.
   , logStdErr      :: Bool -- ^ Redirect the server's stderr to this stdout, defaults to False.
-  , logMessages    :: Bool -- ^ Trace the messages sent and received to stdout, defaults to True.
+  , logMessages    :: Bool -- ^ Trace the messages sent and received to stdout, defaults to False.
   , logColor       :: Bool -- ^ Add ANSI color to the logged messages, defaults to True.
   }
 
@@ -144,6 +148,11 @@ instance Monad m => HasState SessionState (ConduitM a b (StateT SessionState m))
 
 type ParserStateReader a s r m = ConduitParser a (StateT s (ReaderT r m))
 
+#if __GLASGOW_HASKELL__ >= 806
+instance (Fail.MonadFail m) => Fail.MonadFail (ParserStateReader a s r m) where
+  fail = Fail.fail
+#endif
+
 runSession :: SessionContext -> SessionState -> Session a -> IO (a, SessionState)
 runSession context state session = runReaderT (runStateT conduit state) context
   where