From 147dd90ee7e706364f5c96a66b4a1aead8bef930 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Gr=C3=B6ber?= <dxld@darkboxed.org>
Date: Tue, 19 Aug 2014 04:49:44 +0200
Subject: [PATCH] Remove dedicated exception handling in `check` completely

Exceptions are already caught at the top level so this is unnecessary.
---
 Language/Haskell/GhcMod/Check.hs |  5 ++---
 Language/Haskell/GhcMod/Types.hs |  3 ---
 Language/Haskell/GhcMod/Utils.hs | 13 -------------
 src/GHCMod.hs                    |  2 --
 4 files changed, 2 insertions(+), 21 deletions(-)

diff --git a/Language/Haskell/GhcMod/Check.hs b/Language/Haskell/GhcMod/Check.hs
index 88ace61..c2ea2a4 100644
--- a/Language/Haskell/GhcMod/Check.hs
+++ b/Language/Haskell/GhcMod/Check.hs
@@ -12,7 +12,6 @@ import qualified GHC as G
 import Language.Haskell.GhcMod.Logger
 import Language.Haskell.GhcMod.Monad (IOish, GhcModT, overrideGhcUserOptions)
 import Language.Haskell.GhcMod.Target (setTargetFiles)
-import Language.Haskell.GhcMod.Utils (liftExceptions)
 
 ----------------------------------------------------------------
 
@@ -22,7 +21,7 @@ checkSyntax :: IOish m
             => [FilePath]  -- ^ The target files.
             -> GhcModT m String
 checkSyntax []    = return ""
-checkSyntax files = liftExceptions $ either id id <$> check files
+checkSyntax files = either id id <$> check files
 
 ----------------------------------------------------------------
 
@@ -47,7 +46,7 @@ expandTemplate :: IOish m
                => [FilePath]  -- ^ The target files.
                -> GhcModT m String
 expandTemplate []    = return ""
-expandTemplate files = liftExceptions $ either id id <$> expand files
+expandTemplate files = either id id <$> expand files
 
 ----------------------------------------------------------------
 
diff --git a/Language/Haskell/GhcMod/Types.hs b/Language/Haskell/GhcMod/Types.hs
index 8313aae..6f7dbe9 100644
--- a/Language/Haskell/GhcMod/Types.hs
+++ b/Language/Haskell/GhcMod/Types.hs
@@ -2,15 +2,12 @@ module Language.Haskell.GhcMod.Types where
 
 import Data.List (intercalate)
 import qualified Data.Map as M
-import Control.Exception (SomeException)
 import Control.Monad.Error (Error(..))
 
 import PackageConfig (PackageConfig)
 
 data GhcModError = GMENoMsg
                  -- ^ Unknown error
-                 | GMEException SomeException
-                 -- ^ Regular exception lifted by 'liftExceptions'
                  | GMEString { gmeMsg :: String }
                  -- ^ Some Error with a message. These are produced mostly by
                  -- 'fail' calls on GhcModT.
diff --git a/Language/Haskell/GhcMod/Utils.hs b/Language/Haskell/GhcMod/Utils.hs
index 30597f9..37a33b1 100644
--- a/Language/Haskell/GhcMod/Utils.hs
+++ b/Language/Haskell/GhcMod/Utils.hs
@@ -2,7 +2,6 @@ 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)
@@ -10,7 +9,6 @@ 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]
@@ -64,14 +62,3 @@ liftIOExceptions action = do
     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
diff --git a/src/GHCMod.hs b/src/GHCMod.hs
index 41e9e38..5d5b414 100644
--- a/src/GHCMod.hs
+++ b/src/GHCMod.hs
@@ -141,8 +141,6 @@ main = flip E.catches handlers $ do
       cmd       -> E.throw (NoSuchCommand cmd)
     case res of
       Right s -> putStr s
-      Left (GMEException e) ->
-          hPutStrLn stderr $ "Exception: " ++ show e
       Left (GMENoMsg) ->
           hPutStrLn stderr "Unknown error"
       Left (GMEString msg) ->