adopting hlint's suggestions.

Language/Haskell/GhcMod/CabalConfig.hs

@@ -14,6 +14,10 @@ import Language.Haskell.GhcMod.Types
 import qualified Language.Haskell.GhcMod.Cabal16 as C16
 import qualified Language.Haskell.GhcMod.Cabal18 as C18
 
+#ifndef MIN_VERSION_mtl
+#define MIN_VERSION_mtl(x,y,z) 1
+#endif
+
 import qualified Control.Exception as E
 import Control.Applicative ((<$>))
 import Control.Monad (mplus)
@@ -59,7 +63,7 @@ configDependencies :: PackageIdentifier -> CabalConfig -> [Package]
 configDependencies thisPkg config = map fromInstalledPackageId deps
  where
     deps :: [InstalledPackageId]
-    deps = case (deps18 `mplus` deps16) of
+    deps = case deps18 `mplus` deps16 of
         Right ps -> ps
         Left msg -> error msg
 

Language/Haskell/GhcMod/CaseSplit.hs

@@ -184,7 +184,7 @@ getBindingText text srcSpan =
            [T.drop (sc - 1) $ T.take ec $ head lines_]
       else -- several lines
             let (first,rest,last_) = (head lines_, tail $ init lines_, last lines_)
-             in (T.drop (sc - 1) first) : rest ++ [T.take ec last_]
+             in T.drop (sc - 1) first : rest ++ [T.take ec last_]
 
 srcSpanDifference :: SrcSpan -> SrcSpan -> (Int,Int,Int,Int)
 srcSpanDifference b v =

Language/Haskell/GhcMod/Check.hs

@@ -19,7 +19,7 @@ checkSyntax :: IOish m
             => [FilePath]  -- ^ The target files.
             -> GhcModT m String
 checkSyntax [] = return ""
-checkSyntax files = withErrorHandler sessionName $ do
+checkSyntax files = withErrorHandler sessionName $
     either id id <$> check files
   where
     sessionName = case files of
@@ -33,8 +33,7 @@ checkSyntax files = withErrorHandler sessionName $ do
 check :: IOish m
       => [FilePath]  -- ^ The target files.
       -> GhcModT m (Either String String)
-check fileNames = do
+check fileNames = withLogger setAllWaringFlags $ setTargetFiles fileNames
-  withLogger setAllWaringFlags $ setTargetFiles fileNames
 
 ----------------------------------------------------------------
 
@@ -43,7 +42,7 @@ expandTemplate :: IOish m
                => [FilePath]  -- ^ The target files.
                -> GhcModT m String
 expandTemplate [] = return ""
-expandTemplate files = withErrorHandler sessionName $ do
+expandTemplate files = withErrorHandler sessionName $
     either id id <$> expand files
   where
     sessionName = case files of

Language/Haskell/GhcMod/Convert.hs

@@ -81,14 +81,14 @@ instance ToString ((Int,Int,Int,Int),String) where
     toPlain opt x = tupToString opt x
 
 instance ToString (String, (Int,Int,Int,Int),[String]) where
-    toLisp  opt (s,x,y) = toSexp2 $ [toLisp opt s, ('(' :) . fourIntsToString opt x . (')' :), toLisp opt y]
+    toLisp  opt (s,x,y) = toSexp2 [toLisp opt s, ('(' :) . fourIntsToString opt x . (')' :), toLisp opt y]
     toPlain opt (s,x,y) = inter '\n' [toPlain opt s, fourIntsToString opt x, toPlain opt y]
 
 toSexp1 :: Options -> [String] -> Builder
 toSexp1 opt ss = ('(' :) . inter ' ' (map (quote opt) ss) . (')' :)
 
 toSexp2 :: [Builder] -> Builder
-toSexp2 ss = ('(' :) . (inter ' ' ss) . (')' :)
+toSexp2 ss = ('(' :) . inter ' ' ss . (')' :)
 
 fourIntsToString :: Options -> (Int,Int,Int,Int) -> Builder
 fourIntsToString _ (a,b,c,d) = (show a ++) . (' ' :)

Language/Haskell/GhcMod/Cradle.hs

@@ -22,8 +22,7 @@ import System.FilePath ((</>), takeDirectory)
 --   Find a sandbox according to a cabal sandbox config
 --   in a cabal directory.
 findCradle :: IO Cradle
-findCradle = do
+findCradle = findCradle' =<< getCurrentDirectory
-    findCradle' =<< getCurrentDirectory
 
 findCradle' :: FilePath -> IO Cradle
 findCradle' dir = cabalCradle dir ||> sandboxCradle dir ||> plainCradle dir

Language/Haskell/GhcMod/Debug.hs

@@ -16,7 +16,7 @@ debugInfo :: IOish m => GhcModT m String
 debugInfo = cradle >>= \c -> convert' =<< do
     CompilerOptions gopts incDir pkgs <-
         if isJust $ cradleCabalFile c then
-            (fromCabalFile c ||> simpleCompilerOption)
+            fromCabalFile c ||> simpleCompilerOption
           else
             simpleCompilerOption
     return [

Language/Haskell/GhcMod/DynFlags.hs

@@ -101,8 +101,7 @@ needsFallback = any (hasTHorQQ . G.ms_hspp_opts)
 
 -- | Return the 'DynFlags' currently in use in the GHC session.
 getDynamicFlags :: IO DynFlags
-getDynamicFlags = do
+getDynamicFlags = G.runGhc (Just libdir) G.getSessionDynFlags
-    G.runGhc (Just libdir) G.getSessionDynFlags
 
 withDynFlags :: GhcMonad m
              => (DynFlags -> DynFlags)
@@ -136,7 +135,7 @@ setAllWaringFlags :: DynFlags -> DynFlags
 setAllWaringFlags df = df { warningFlags = allWarningFlags }
 
 allWarningFlags :: Gap.WarnFlags
-allWarningFlags = unsafePerformIO $ do
+allWarningFlags = unsafePerformIO $
     G.runGhc (Just libdir) $ do
         df <- G.getSessionDynFlags
         df' <- addCmdOpts ["-Wall"] df

Language/Haskell/GhcMod/FillSig.hs

@@ -5,7 +5,7 @@ module Language.Haskell.GhcMod.FillSig (
   ) where
 
 import Data.Char (isSymbol)
-import Data.List (find, intercalate)
+import Data.List (find)
 import Exception (ghandle, SomeException(..))
 import GHC (GhcMonad, Id, ParsedModule(..), TypecheckedModule(..), DynFlags, SrcSpan, Type, GenLocated(L))
 import qualified GHC as G
@@ -45,7 +45,7 @@ sig file lineNo colNo = ghandle handler body
         whenFound opt (getSignature modSum lineNo colNo) $ \s -> case s of
           Signature loc names ty ->
             ("function", fourInts loc, map (initialBody dflag style ty) names)
-          InstanceDecl loc cls -> do
+          InstanceDecl loc cls ->
              ("instance", fourInts loc, map (\x -> initialBody dflag style (G.idType x) x)
                                             (Ty.classMethods cls))
 
@@ -109,8 +109,8 @@ initialBody' fname args =
   case initialBodyArgs args infiniteVars infiniteFns of
     []      -> fname
     arglist -> if isSymbolName fname
-               then (head arglist) ++ " " ++ fname ++ " " ++ (intercalate " " (tail arglist))
+               then head arglist ++ " " ++ fname ++ " " ++ unwords (tail arglist)
-               else fname ++ " " ++ (intercalate " " arglist)
+               else fname ++ " " ++ unwords arglist
   ++ " = " ++ (if isSymbolName fname then "" else '_':fname) ++ "_body"
 
 initialBodyArgs :: [FnArg] -> [String] -> [String] -> [String]
@@ -133,7 +133,7 @@ instance FnArgsInfo (G.HsType G.RdrName) (G.RdrName) where
   getFnArgs (G.HsForAllTy _ _ _ (L _ iTy))  = getFnArgs iTy
   getFnArgs (G.HsParTy (L _ iTy))           = getFnArgs iTy
   getFnArgs (G.HsFunTy (L _ lTy) (L _ rTy)) = (if fnarg lTy then FnArgFunction else FnArgNormal):getFnArgs rTy
-    where fnarg = \ty -> case ty of
+    where fnarg ty = case ty of
               (G.HsForAllTy _ _ _ (L _ iTy)) -> fnarg iTy
               (G.HsParTy (L _ iTy))          -> fnarg iTy
               (G.HsFunTy _ _)                -> True
@@ -146,7 +146,7 @@ instance FnArgsInfo (HE.Type HE.SrcSpanInfo) (HE.Name HE.SrcSpanInfo) where
   getFnArgs (HE.TyForall _ _ _ iTy) = getFnArgs iTy
   getFnArgs (HE.TyParen _ iTy)      = getFnArgs iTy
   getFnArgs (HE.TyFun _ lTy rTy)    = (if fnarg lTy then FnArgFunction else FnArgNormal):getFnArgs rTy
-    where fnarg = \ty -> case ty of
+    where fnarg ty = case ty of
               (HE.TyForall _ _ _ iTy) -> fnarg iTy
               (HE.TyParen _ iTy)      -> fnarg iTy
               (HE.TyFun _ _ _)        -> True

Language/Haskell/GhcMod/Find.hs

@@ -1,4 +1,4 @@
-{-# LANGUAGE CPP, BangPatterns #-}
+{-# LANGUAGE CPP #-}
 
 module Language.Haskell.GhcMod.Find (
     Symbol
@@ -118,7 +118,7 @@ dumpSymbol = do
                 when create $ do
                     sm <- getSymbol
                     void . liftIO $ withFile cache WriteMode $ \hdl ->
-                        mapM (hPutStrLn hdl . show) sm
+                        mapM (hPrint hdl) sm
                 return cache
     return $ ret ++ "\n"
 

Language/Haskell/GhcMod/GHCApi.hs

@@ -1,4 +1,4 @@
-{-# LANGUAGE ScopedTypeVariables, RecordWildCards #-}
+{-# LANGUAGE ScopedTypeVariables #-}
 
 module Language.Haskell.GhcMod.GHCApi (
     ghcPkgDb
@@ -42,8 +42,7 @@ modules :: G.PackageConfig -> [ModuleString]
 modules = map G.moduleNameString . G.exposedModules
 
 findModule :: ModuleString -> PkgDb -> [Package]
-findModule m db = do
+findModule m db = M.elems $ package `M.map` (containsModule `M.filter` db)
-  M.elems $ package `M.map` (containsModule `M.filter` db)
  where
     containsModule :: G.PackageConfig -> Bool
     containsModule pkgConf =
@@ -83,5 +82,4 @@ localModuleInfo :: GhcMonad m => ModuleString -> m (Maybe G.ModuleInfo)
 localModuleInfo mdl = moduleInfo Nothing mdl
 
 bindings :: G.ModuleInfo -> [Binding]
-bindings minfo = do
+bindings minfo = map (G.occNameString . G.getOccName) $ G.modInfoExports minfo
-  map (G.occNameString . G.getOccName) $ G.modInfoExports minfo

Language/Haskell/GhcMod/Lint.hs

@@ -16,7 +16,7 @@ lint :: IOish m
      -> GhcModT m String
 lint file = do
   opt <- options
-  ghandle handler . pack =<< (liftIO $ hlint $ file : "--quiet" : hlintOpts opt)
+  ghandle handler . pack =<< liftIO (hlint $ file : "--quiet" : hlintOpts opt)
  where
     pack = convert' . map (init . show) -- init drops the last \n.
     handler (SomeException e) = return $ checkErrorPrefix ++ show e ++ "\n"

Language/Haskell/GhcMod/List.hs

@@ -16,7 +16,7 @@ import UniqFM (eltsUFM)
 modules :: IOish m => GhcModT m String
 modules = do
     opt <- options
-    convert opt . (arrange opt) <$> (getModules `G.gcatch` handler)
+    convert opt . arrange opt <$> (getModules `G.gcatch` handler)
   where
     getModules = getExposedModules <$> G.getSessionDynFlags
     getExposedModules = concatMap exposedModules'

Language/Haskell/GhcMod/Logger.hs

@@ -1,4 +1,4 @@
-{-# LANGUAGE BangPatterns, CPP #-}
+{-# LANGUAGE CPP #-}
 
 module Language.Haskell.GhcMod.Logger (
     withLogger
@@ -63,9 +63,9 @@ withLogger :: IOish m
            -> GhcModT m ()
            -> GhcModT m (Either String String)
 withLogger setDF body = ghandle sourceError $ do
-    logref <- liftIO $ newLogRef
+    logref <- liftIO newLogRef
     wflags <- filter ("-fno-warn" `isPrefixOf`) . ghcOpts <$> options
-    withDynFlags (setLogger logref . setDF) $ do
+    withDynFlags (setLogger logref . setDF) $
         withCmdFlags wflags $ do
             body
             Right <$> readAndClearLogRef logref
@@ -80,7 +80,7 @@ sourceError :: IOish m => SourceError -> GhcModT m (Either String String)
 sourceError err = do
     dflags <- G.getSessionDynFlags
     style <- toGhcMod getStyle
-    ret <- convert' $ (errBagToStrList dflags style . srcErrorMessages $ err)
+    ret <- convert' (errBagToStrList dflags style . srcErrorMessages $ err)
     return $ Left ret
 
 errBagToStrList :: DynFlags -> PprStyle -> Bag ErrMsg -> [String]

Language/Haskell/GhcMod/Monad.hs

@@ -188,8 +188,8 @@ initSession :: GhcMonad m
             -> m ()
 initSession build Options {..} CompilerOptions {..} = do
     df <- G.getSessionDynFlags
-    void $ G.setSessionDynFlags =<< (addCmdOpts ghcOptions
+    void $ G.setSessionDynFlags =<< addCmdOpts ghcOptions
-      $ setModeSimple
+      ( setModeSimple
       $ setIncludeDirs includeDirs
       $ setBuildEnv build
       $ setEmptyLogger

Language/Haskell/GhcMod/Utils.hs

@@ -18,7 +18,7 @@ extractParens str = extractParens' str 0
    extractParens' (s:ss) level
        | s `elem` "([{" = s : extractParens' ss (level+1)
        | level == 0 = extractParens' ss 0
-       | s `elem` "}])" && level == 1 = s:[]
+       | s `elem` "}])" && level == 1 = [s]
        | s `elem` "}])" = s : extractParens' ss (level-1)
        | otherwise = s : extractParens' ss level