Remove withErrorHandler, use liftExceptions instead

Language/Haskell/GhcMod/Utils.hs

@@ -2,6 +2,7 @@ module Language.Haskell.GhcMod.Utils where
 
 
 import MonadUtils (MonadIO, liftIO)
+import Exception (ExceptionMonad, gtry)
 import Control.Exception
 import Control.Monad.Error (MonadError(..), Error(..))
 import System.Directory (getCurrentDirectory, setCurrentDirectory)
@@ -9,7 +10,7 @@ import System.Process (readProcessWithExitCode)
 import System.Exit (ExitCode(..))
 import System.IO (hPutStrLn, stderr)
 import System.IO.Error (tryIOError)
-
+import Language.Haskell.GhcMod.Types
 
 -- dropWhileEnd is not provided prior to base 4.5.0.0.
 dropWhileEnd :: (a -> Bool) -> [a] -> [a]
@@ -53,11 +54,24 @@ tryFix :: MonadError e m => m a -> (e -> m ()) -> m a
 tryFix action fix = do
   action `catchError` \e -> fix e >> action
 
-liftMonadError :: (MonadIO m, Error e, MonadError e m) => IO a -> m a
-liftMonadError action = do
+-- | 'IOException's thrown in the computation passed to this function will be
+-- converted to 'MonadError' failures using 'throwError'.
+liftIOExceptions :: (MonadIO m, Error e, MonadError e m) => IO a -> m a
+liftIOExceptions action = do
   res <- liftIO $ tryIOError action
   case res of
     Right a -> return a
     Left e -> case show e of
                 ""  -> throwError $ noMsg
                 msg -> throwError $ strMsg msg
+
+-- | Exceptions thrown in the computation passed to this function will be
+-- converted to 'MonadError' failures using 'throwError'.
+liftExceptions :: (MonadIO m, ExceptionMonad m, MonadError GhcModError m)
+               => m a
+               -> m a
+liftExceptions action = do
+  res <- gtry action
+  case res of
+    Right a -> return a
+    Left e -> throwError $ GMEException e