hlint configuration

25 files changed, 140 insertions, 92 deletions

diff --git a/.hlint.yaml b/.hlint.yaml
new file mode 100644
index 0000000..b68de82
--- /dev/null
+++ b/.hlint.yaml
@@ -0,0 +1,68 @@
+# HLint configuration file
+# https://github.com/ndmitchell/hlint
+##########################
+
+# This file contains a template configuration file, which is typically
+# placed as .hlint.yaml in the root of your project
+
+
+# Warnings currently triggered by your code
+- ignore: {name: "Use module export list"}
+- ignore: {name: "Redundant True guards"}
+- ignore: {name: "Use <$>"}
+- ignore: {name: "Use uncurry"}
+- ignore: {name: "Reduce duplication"}
+
+
+# Specify additional command line arguments
+#
+# - arguments: [--color, --cpp-simple, -XQuasiQuotes]
+
+
+# Control which extensions/flags/modules/functions can be used
+#
+# - extensions:
+#   - default: false # all extension are banned by default
+#   - name: [PatternGuards, ViewPatterns] # only these listed extensions can be used
+#   - {name: CPP, within: CrossPlatform} # CPP can only be used in a given module
+#
+# - flags:
+#   - {name: -w, within: []} # -w is allowed nowhere
+#
+# - modules:
+#   - {name: [Data.Set, Data.HashSet], as: Set} # if you import Data.Set qualified, it must be as 'Set'
+#   - {name: Control.Arrow, within: []} # Certain modules are banned entirely
+#
+# - functions:
+#   - {name: unsafePerformIO, within: []} # unsafePerformIO can only appear in no modules
+
+
+# Add custom hints for this project
+#
+# Will suggest replacing "wibbleMany [myvar]" with "wibbleOne myvar"
+# - error: {lhs: "wibbleMany [x]", rhs: wibbleOne x}
+
+
+# Turn on hints that are off by default
+#
+# Ban "module X(module X) where", to require a real export list
+# - warn: {name: Use explicit module export list}
+#
+# Replace a $ b $ c with a . b $ c
+# - group: {name: dollar, enabled: true}
+#
+# Generalise map to fmap, ++ to <>
+# - group: {name: generalise, enabled: true}
+
+
+# Ignore some builtin hints
+# - ignore: {name: Use let}
+# - ignore: {name: Use const, within: SpecialModule} # Only within certain modules
+
+
+# Define some custom infix operators
+# - fixity: infixr 3 ~^#^~
+
+
+# To generate a suitable file for HLint do:
+# $ hlint --default > .hlint.yaml
diff --git a/src/Bitmap.hs b/src/Bitmap.hs
index 0f0c746..1acc0b7 100644
--- a/src/Bitmap.hs
+++ b/src/Bitmap.hs
@@ -2,7 +2,7 @@
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Bitmap
--- Copyright   :  (C) 2013, 2015 Alexander Polakov
+-- Copyright   :  (C) 2013, 2015, 2017 Alexander Polakov
 -- License     :  BSD3
 --
 -- Maintainer  :  jao@gnu.org
@@ -86,8 +86,7 @@ loadBitmap d w p = do
     exist <- doesFileExist p
     if exist
        then do
-            res <- runExceptT $
-                    tryXBM
+            res <- runExceptT $ tryXBM
 #ifdef XPM
                 <|> tryXPM
 #endif
@@ -121,7 +120,7 @@ drawBitmap d p gc fc bc x y i =
         y' = 1 + y - fromIntegral h `div` 2
     setForeground d gc fc'
     setBackground d gc bc'
-    case (shapePixmap i) of
+    case shapePixmap i of
          Nothing -> return ()
          Just mask -> setClipOrigin d gc x y' >> setClipMask d gc mask
     case bitmapType i of
diff --git a/src/Environment.hs b/src/Environment.hs
index 120dac6..1b7e48c 100644
--- a/src/Environment.hs
+++ b/src/Environment.hs
@@ -11,7 +11,7 @@
 -- A function to expand environment variables in strings
 --
 -----------------------------------------------------------------------------
-module Environment where
+module Environment(expandEnv) where
 
 import Control.Applicative  ((<$>))
 import Data.Maybe           (fromMaybe)
diff --git a/src/IWlib.hsc b/src/IWlib.hsc
index 5f7754d..b244510 100644
--- a/src/IWlib.hsc
+++ b/src/IWlib.hsc
@@ -56,7 +56,7 @@ getWirelessInfo iface =
     str <- c_iw_stats i istr stats rng 1
     rgr <- c_iw_range i istr rng
     c_iw_close i
-    if (bcr < 0) then return WirelessInfo { wiEssid = "", wiQuality = 0 } else
+    if bcr < 0 then return WirelessInfo { wiEssid = "", wiQuality = 0 } else
       do hase <- (#peek struct wireless_config, has_essid) wc :: IO CInt
          eon <- (#peek struct wireless_config, essid_on) wc :: IO CInt
          essid <- if hase /= 0 && eon /= 0 then
@@ -70,6 +70,6 @@ getWirelessInfo iface =
                    return $ fromIntegral qualv / mxv
               else return 0
          let qv = round (100 * (q :: Double))
-         return $ WirelessInfo { wiEssid = essid, wiQuality = min 100 qv }
+         return WirelessInfo { wiEssid = essid, wiQuality = min 100 qv }
     where xqual p = let qp = (#ptr struct iw_param, value) p in
             (#peek struct iw_quality, qual) qp :: IO CChar
diff --git a/src/Localize.hsc b/src/Localize.hsc
index b3f7d53..34d0fd9 100644
--- a/src/Localize.hsc
+++ b/src/Localize.hsc
@@ -50,7 +50,7 @@ getLangInfo item = do
   itemStr <- nl_langinfo item
 #ifdef UTF8
   str <- peekCString itemStr
-  return $ if (isUTF8Encoded str) then decodeString str else str
+  return $ if isUTF8Encoded str then decodeString str else str
 #else
   peekCString itemStr
 #endif
diff --git a/src/Main.hs b/src/Main.hs
index 0596600..288939d 100644
--- a/src/Main.hs
+++ b/src/Main.hs
@@ -37,7 +37,7 @@ import System.Exit
 import System.Environment
 import System.FilePath ((</>))
 import System.Posix.Files
-import Control.Monad (unless, liftM)
+import Control.Monad (unless)
 import Text.Read (readMaybe)
 
 import Signal (setupSignalHandler)
@@ -96,13 +96,13 @@ xdgConfigDir :: IO String
 xdgConfigDir = do env <- getEnvironment
                   case lookup "XDG_CONFIG_HOME" env of
                        Just val -> return val
-                       Nothing  -> liftM (</> ".config") getHomeDirectory
+                       Nothing  -> fmap (</> ".config") getHomeDirectory
 
 xmobarConfigDir :: IO FilePath
-xmobarConfigDir = liftM (</> "xmobar") xdgConfigDir
+xmobarConfigDir = fmap (</> "xmobar") xdgConfigDir
 
 getXdgConfigFile :: IO FilePath
-getXdgConfigFile = liftM (</> "xmobarrc") xmobarConfigDir
+getXdgConfigFile = fmap (</> "xmobarrc") xmobarConfigDir
 
 -- | Read default configuration file or load the default config
 readDefaultConfig :: IO (Config,[String])
@@ -231,7 +231,7 @@ doOpts conf (o:oo) =
                         "specified with the -" ++ c:" option\n")
         readStr str = [x | (x,t) <- reads str, ("","") <- lex t]
         doOpts' opts = doOpts opts oo
-        readPosition string = 
+        readPosition string =
             case readMaybe string of
                 Just x  -> doOpts' (conf { position = x })
                 Nothing -> do
diff --git a/src/MinXft.hsc b/src/MinXft.hsc
index 148efe7..b64a8b8 100644
--- a/src/MinXft.hsc
+++ b/src/MinXft.hsc
@@ -1,7 +1,7 @@
 ------------------------------------------------------------------------------
 -- |
 -- Module: MinXft
--- Copyright: (c) 2012, 2014, 2015 Jose Antonio Ortega Ruiz
+-- Copyright: (c) 2012, 2014, 2015, 2017 Jose Antonio Ortega Ruiz
 --            (c) Clemens Fruhwirth <clemens@endorphin.org> 2007
 -- License: BSD3-style (see LICENSE)
 --
@@ -179,7 +179,7 @@ drawXftString' d c fs x y string = do
     mapM_ (\(f, s, _, xo, yo) -> drawXftString d c f (x+xo) (y+yo) s) chunks
 
 -- Split string and determine fonts/offsets for individual parts
-getChunks :: Display -> [AXftFont] -> [Char] ->
+getChunks :: Display -> [AXftFont] -> String ->
              IO [(AXftFont, String, XGlyphInfo, Integer, Integer)]
 getChunks disp fts str = do
     chunks <- getFonts disp fts str
@@ -253,7 +253,7 @@ instance Storable XRenderPictureAttributes where
     sizeOf _ = #{size XRenderPictureAttributes}
     alignment _ = alignment (undefined :: CInt)
     peek _ = return XRenderPictureAttributes
-    poke p XRenderPictureAttributes = do
+    poke p XRenderPictureAttributes =
         memset p 0 #{size XRenderPictureAttributes}
 
 -- | Convenience function, gives us an XRender handle to a traditional
diff --git a/src/Parsers.hs b/src/Parsers.hs
index 25d215b..5f5949c 100644
--- a/src/Parsers.hs
+++ b/src/Parsers.hs
@@ -25,7 +25,7 @@ import Runnable
 import Commands
 import Actions
 
-import Control.Monad (guard, mzero, liftM)
+import Control.Monad (guard, mzero)
 import qualified Data.Map as Map
 import Text.ParserCombinators.Parsec
 import Text.ParserCombinators.Parsec.Perm
@@ -276,7 +276,7 @@ parseConfig = runParser parseConf fields "Config" . stripComments
                 spaces
                 char lead
                 s <- manyTill anyChar (rowCont <|> unescQuote)
-                (char '"' >> return s) <|> liftM (s ++) (scan '\\')
+                (char '"' >> return s) <|> fmap (s ++) (scan '\\')
             rowCont    = try $ char '\\' >> string "\n"
             unescQuote = lookAhead (noneOf "\\") >> lookAhead (string "\"")
 
diff --git a/src/Plugins/BufferedPipeReader.hs b/src/Plugins/BufferedPipeReader.hs
index b6cad9d..eeb330b 100644
--- a/src/Plugins/BufferedPipeReader.hs
+++ b/src/Plugins/BufferedPipeReader.hs
@@ -27,6 +27,7 @@ import Signal
 data BufferedPipeReader = BufferedPipeReader String [(Int, Bool, String)]
     deriving (Read, Show)
 
+{-# NOINLINE signal #-}
 signal :: MVar SignalType
 signal = unsafePerformIO newEmptyMVar
 
diff --git a/src/Plugins/Date.hs b/src/Plugins/Date.hs
index cd688e6..b2d32da 100644
--- a/src/Plugins/Date.hs
+++ b/src/Plugins/Date.hs
@@ -24,7 +24,6 @@ import Plugins
 #if ! MIN_VERSION_time(1,5,0)
 import System.Locale
 #endif
-import Control.Monad (liftM)
 import Data.Time
 
 data Date = Date String String Int
@@ -36,4 +35,4 @@ instance Exec Date where
     rate  (Date _ _ r) = r
 
 date :: String -> IO String
-date format = liftM (formatTime defaultTimeLocale format) getZonedTime
+date format = fmap (formatTime defaultTimeLocale format) getZonedTime
diff --git a/src/Plugins/EWMH.hs b/src/Plugins/EWMH.hs
index c014aec..63395f0 100644
--- a/src/Plugins/EWMH.hs
+++ b/src/Plugins/EWMH.hs
@@ -150,13 +150,13 @@ getAtom s = do
 
 windowProperty32 :: String -> Window -> M (Maybe [CLong])
 windowProperty32 s w = do
-    (C {display}) <- ask
+    C {display} <- ask
     a <- getAtom s
     liftIO $ getWindowProperty32 display a w
 
 windowProperty8 :: String -> Window -> M (Maybe [CChar])
 windowProperty8 s w = do
-    (C {display}) <- ask
+    C {display} <- ask
     a <- getAtom s
     liftIO $ getWindowProperty8 display a w
 
@@ -190,21 +190,21 @@ type Updater = Window -> M ()
 
 updateCurrentDesktop, updateDesktopNames, updateActiveWindow :: Updater
 updateCurrentDesktop _ = do
-    (C {root}) <- ask
+    C {root} <- ask
     mwp <- windowProperty32 "_NET_CURRENT_DESKTOP" root
     case mwp of
         Just [x] -> modify (\s -> s { currentDesktop = x })
         _        -> return ()
 
 updateActiveWindow _ = do
-    (C {root}) <- ask
+    C {root} <- ask
     mwp <- windowProperty32 "_NET_ACTIVE_WINDOW" root
     case mwp of
         Just [x] -> modify (\s -> s { activeWindow = fromIntegral x })
         _        -> return ()
 
 updateDesktopNames _ = do
-    (C {root}) <- ask
+    C {root} <- ask
     mwp <- windowProperty8 "_NET_DESKTOP_NAMES" root
     case mwp of
         Just xs -> modify (\s -> s { desktopNames = parse xs })
@@ -219,7 +219,7 @@ updateDesktopNames _ = do
     parse = split . decodeCChar
 
 updateClientList _ = do
-    (C {root}) <- ask
+    C {root} <- ask
     mwp <- windowProperty32 "_NET_CLIENT_LIST" root
     case mwp of
         Just xs -> do
diff --git a/src/Plugins/Kbd.hsc b/src/Plugins/Kbd.hsc
index 59854f5..c582634 100644
--- a/src/Plugins/Kbd.hsc
+++ b/src/Plugins/Kbd.hsc
@@ -380,7 +380,7 @@ instance Exec Kbd where
         dpy <- openDisplay ""
 
         -- initial set of layout
-        cb =<< (getKbdLay dpy opts)
+        cb =<< getKbdLay dpy opts
 
         -- enable listing for
         -- group changes
@@ -391,7 +391,7 @@ instance Exec Kbd where
         allocaXEvent $ \e -> forever $ do
             nextEvent' dpy e
             _ <- getEvent e
-            cb =<< (getKbdLay dpy opts)
+            cb =<< getKbdLay dpy opts
 
         closeDisplay dpy
         return ()
diff --git a/src/Plugins/Monitors.hs b/src/Plugins/Monitors.hs
index 84eceb2..43068be 100644
--- a/src/Plugins/Monitors.hs
+++ b/src/Plugins/Monitors.hs
@@ -3,7 +3,7 @@
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Xmobar.Plugins.Monitors
--- Copyright   :  (c) 2010, 2011, 2012, 2013 Jose Antonio Ortega Ruiz
+-- Copyright   :  (c) 2010, 2011, 2012, 2013, 2017 Jose Antonio Ortega Ruiz
 --                (c) 2007-10 Andrea Rossato
 -- License     :  BSD-style (see LICENSE)
 --
@@ -114,15 +114,15 @@ instance Exec Monitors where
     alias (Cpu _ _) = "cpu"
     alias (MultiCpu _ _) = "multicpu"
     alias (Battery _ _) = "battery"
-    alias (BatteryP {})= "battery"
+    alias BatteryP {} = "battery"
     alias (BatteryN _ _ _ a)= a
     alias (Brightness _ _) = "bright"
     alias (CpuFreq _ _) = "cpufreq"
     alias (TopProc _ _) = "top"
     alias (TopMem _ _) = "topmem"
     alias (CoreTemp _ _) = "coretemp"
-    alias (DiskU {}) = "disku"
-    alias (DiskIO {}) = "diskio"
+    alias DiskU {} = "disku"
+    alias DiskIO {} = "diskio"
     alias (Uptime _ _) = "uptime"
     alias (CatInt n _ _ _) = "cat" ++ show n
 #ifdef UVMETER
diff --git a/src/Plugins/Monitors/Common.hs b/src/Plugins/Monitors/Common.hs
index ef509e9..5f088cf 100644
--- a/src/Plugins/Monitors/Common.hs
+++ b/src/Plugins/Monitors/Common.hs
@@ -1,7 +1,7 @@
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Plugins.Monitors.Common
--- Copyright   :  (c) 2010, 2011, 2013, 2016 Jose Antonio Ortega Ruiz
+-- Copyright   :  (c) 2010, 2011, 2013, 2016, 2017 Jose Antonio Ortega Ruiz
 --                (c) 2007-2010 Andrea Rossato
 -- License     :  BSD-style (see LICENSE)
 --
@@ -296,7 +296,7 @@ templateStringParser =
        ; return (s, com, ss)
        }
     where
-      nonPlaceHolder = liftM concat . many $
+      nonPlaceHolder = fmap concat . many $
                        many1 (noneOf "<") <|> colorSpec <|> iconSpec
 
 -- | Recognizes color specification and returns it unchanged
@@ -365,7 +365,7 @@ type IconPattern = Int -> String
 parseIconPattern :: String -> IconPattern
 parseIconPattern path =
     let spl = splitOnPercent path
-    in \i -> concat $ intersperse (show i) spl
+    in \i -> intercalate (show i) spl
   where splitOnPercent [] = [[]]
         splitOnPercent ('%':'%':xs) = [] : splitOnPercent xs
         splitOnPercent (x:xs) =
@@ -466,7 +466,7 @@ showPercentsWithColors fs =
      zipWithM (showWithColors . const) fstrs (map (*100) fs)
 
 showPercentWithColors :: Float -> Monitor String
-showPercentWithColors f = liftM head $ showPercentsWithColors [f]
+showPercentWithColors f = fmap head $ showPercentsWithColors [f]
 
 showPercentBar :: Float -> Float -> Monitor String
 showPercentBar v x = do
@@ -495,37 +495,22 @@ showVerticalBar v x = colorizeString v [convert $ 100 * x]
           | otherwise = chr t
           where t = 9600 + (round val `div` 12)
 
-showLogBar :: Float -> Float -> Monitor String
-showLogBar f v =
-  let intConfig c = fromIntegral `fmap` getConfigValue c
-  in do
-    h <- intConfig high
-    l <- intConfig low
-    bw <- intConfig barWidth
-    let [ll, hh] = sort [l, h]
-        choose x | x == 0.0 = 0
-                 | x <= ll = 1 / bw
-                 | otherwise = f + logBase 2 (x / hh) / bw
-    showPercentBar v $ choose v
-
-showLogVBar :: Float -> Float -> Monitor String
-showLogVBar f v = do
+logScaling :: Float -> Float -> Monitor Float
+logScaling f v = do
   h <- fromIntegral `fmap` getConfigValue high
   l <- fromIntegral `fmap` getConfigValue low
   bw <- fromIntegral `fmap` getConfigValue barWidth
   let [ll, hh] = sort [l, h]
-      choose x | x == 0.0 = 0
+      scaled x | x == 0.0 = 0
                | x <= ll = 1 / bw
                | otherwise = f + logBase 2 (x / hh) / bw
-  showVerticalBar v $ choose v
+  return $ scaled v
+
+showLogBar :: Float -> Float -> Monitor String
+showLogBar f v = logScaling f v >>= showPercentBar v
+
+showLogVBar :: Float -> Float -> Monitor String
+showLogVBar f v = logScaling f v >>= showPercentBar v
 
 showLogIconPattern :: Maybe IconPattern -> Float -> Float -> Monitor String
-showLogIconPattern str f v = do
-  h <- fromIntegral `fmap` getConfigValue high
-  l <- fromIntegral `fmap` getConfigValue low
-  bw <- fromIntegral `fmap` getConfigValue barWidth
-  let [ll, hh] = sort [l, h]
-      choose x | x == 0.0 = 0
-               | x <= ll = 1 / bw
-               | otherwise = f + logBase 2 (x / hh) / bw
-  showIconPattern str $ choose v
+showLogIconPattern str f v = logScaling f v >>= showIconPattern str
diff --git a/src/Plugins/Monitors/CoreCommon.hs b/src/Plugins/Monitors/CoreCommon.hs
index 943f491..2c10c70 100644
--- a/src/Plugins/Monitors/CoreCommon.hs
+++ b/src/Plugins/Monitors/CoreCommon.hs
@@ -29,7 +29,7 @@ checkedDataRetrieval :: (Ord a, Num a)
                      => String -> [[String]] -> Maybe (String, String -> Int)
                      -> (Double -> a) -> (a -> String) -> Monitor String
 checkedDataRetrieval msg paths lbl trans fmt =
-  liftM (fromMaybe msg . listToMaybe . catMaybes) $
+  fmap (fromMaybe msg . listToMaybe . catMaybes) $
     mapM (\p -> retrieveData p lbl trans fmt) paths
 
 retrieveData :: (Ord a, Num a)
@@ -127,7 +127,7 @@ findFilesAndLabel path lbl  =  catMaybes
 -- | Function to read the contents of the given file(s)
 readFiles :: (String, Either Int (String, String -> Int))
           -> Monitor (Int, String)
-readFiles (fval, flbl) = (,) <$> either return (\(f, ex) -> liftM ex
+readFiles (fval, flbl) = (,) <$> either return (\(f, ex) -> fmap ex
                                                             $ io $ readFile f) flbl
                              <*> io (readFile fval)
 
diff --git a/src/Plugins/Monitors/Cpu.hs b/src/Plugins/Monitors/Cpu.hs
index 7fed989..0dba92a 100644
--- a/src/Plugins/Monitors/Cpu.hs
+++ b/src/Plugins/Monitors/Cpu.hs
@@ -1,7 +1,7 @@
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Plugins.Monitors.Cpu
--- Copyright   :  (c) 2011 Jose Antonio Ortega Ruiz
+-- Copyright   :  (c) 2011, 2017 Jose Antonio Ortega Ruiz
 --                (c) 2007-2010 Andrea Rossato
 -- License     :  BSD-style (see LICENSE)
 --
@@ -20,7 +20,7 @@ import qualified Data.ByteString.Lazy.Char8 as B
 import Data.IORef (IORef, newIORef, readIORef, writeIORef)
 import System.Console.GetOpt
 
-data CpuOpts = CpuOpts
+newtype CpuOpts = CpuOpts
   { loadIconPattern :: Maybe IconPattern
   }
 
diff --git a/src/Plugins/Monitors/Mpris.hs b/src/Plugins/Monitors/Mpris.hs
index 200e9f7..0228c8e 100644
--- a/src/Plugins/Monitors/Mpris.hs
+++ b/src/Plugins/Monitors/Mpris.hs
@@ -78,6 +78,7 @@ mprisConfig = mkMConfig "<artist> - <title>"
                 , "title", "tracknumber" , "composer", "genre"
                 ]
 
+{-# NOINLINE dbusClient #-}
 dbusClient :: DC.Client
 dbusClient = unsafePerformIO DC.connectSession
 
@@ -106,7 +107,7 @@ unpackMetadata xs =
                  TypeVariant -> unpack $ fromVar v
                  TypeStructure _ ->
                    let x = structureItems (fromVar v) in
-                     if x == [] then [] else unpack (head x)
+                     if null x then [] else unpack (head x)
                  _ -> []
 
 getMetadata :: (MprisVersion a) => a -> DC.Client -> String -> IO [(String, Variant)]
@@ -141,5 +142,5 @@ makeList version md = map getStr (fieldsList version) where
                                            _ -> (show::Int64 -> String) num
                             TypeArray TypeString ->
                               let x = arrayItems (fromVar v) in
-                                if x == [] then "" else fromVar (head x)
+                                if null x then "" else fromVar (head x)
                             _ -> ""
diff --git a/src/Plugins/Monitors/MultiCpu.hs b/src/Plugins/Monitors/MultiCpu.hs
index f0cdec4..b290690 100644
--- a/src/Plugins/Monitors/MultiCpu.hs
+++ b/src/Plugins/Monitors/MultiCpu.hs
@@ -96,10 +96,10 @@ formatCpu opts i xs
                       return (b:h:d:ps)
   where tryString
           | i == 0 = loadIconPattern opts
-          | i <= length (loadIconPatterns opts) = Just $ (loadIconPatterns opts) !! (i - 1)
+          | i <= length (loadIconPatterns opts) = Just $ loadIconPatterns opts !! (i - 1)
           | otherwise = Nothing
 
-splitEvery :: (Eq a) => Int -> [a] -> [[a]]
+splitEvery :: Int -> [a] -> [[a]]
 splitEvery n = unfoldr (\x -> if null x then Nothing else Just $ splitAt n x)
 
 groupData :: [String] -> [[String]]
diff --git a/src/Plugins/Monitors/Net.hs b/src/Plugins/Monitors/Net.hs
index 7df8889..a8c2951 100644
--- a/src/Plugins/Monitors/Net.hs
+++ b/src/Plugins/Monitors/Net.hs
@@ -1,7 +1,7 @@
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Plugins.Monitors.Net
--- Copyright   :  (c) 2011, 2012, 2013, 2014 Jose Antonio Ortega Ruiz
+-- Copyright   :  (c) 2011, 2012, 2013, 2014, 2017 Jose Antonio Ortega Ruiz
 --                (c) 2007-2010 Andrea Rossato
 -- License     :  BSD-style (see LICENSE)
 --
@@ -82,8 +82,8 @@ instance Ord num => Ord (NetDev num) where
     compare NA _               = LT
     compare _  NA              = GT
     compare (NI _) (NI _)      = EQ
-    compare (NI _) (ND {})     = LT
-    compare (ND {}) (NI _)     = GT
+    compare (NI _) ND {}       = LT
+    compare ND {} (NI _)     = GT
     compare (ND _ x1 y1) (ND _ x2 y2) =
         if downcmp /= EQ
            then downcmp
@@ -189,7 +189,7 @@ runNets refs argv = do
   dev <- io $ parseActive refs
   opts <- io $ parseOpts argv
   printNet opts dev
-    where parseActive refs' = liftM selectActive (parseNets refs') 
+    where parseActive refs' = fmap selectActive (parseNets refs')
           selectActive = maximum
 
 startNet :: String -> [String] -> Int -> (String -> IO ()) -> IO ()
diff --git a/src/Plugins/Monitors/Thermal.hs b/src/Plugins/Monitors/Thermal.hs
index 6013511..5a97152 100644
--- a/src/Plugins/Monitors/Thermal.hs
+++ b/src/Plugins/Monitors/Thermal.hs
@@ -14,7 +14,6 @@
 
 module Plugins.Monitors.Thermal where
 
-import Control.Monad (liftM)
 import qualified Data.ByteString.Lazy.Char8 as B
 import Plugins.Monitors.Common
 import System.Posix.Files (fileExist)
@@ -34,8 +33,7 @@ runThermal args = do
         file = "/proc/acpi/thermal_zone/" ++ zone ++ "/temperature"
     exists <- io $ fileExist file
     if exists
-        then do number <- io $ liftM ((read :: String -> Int) . stringParser (1, 0)) (B.readFile file)
+        then do number <- io $ fmap ((read :: String -> Int) . stringParser (1, 0)) (B.readFile file)
                 thermal <- showWithColors show number
                 parseTemplate [  thermal ]
         else return $ "Thermal (" ++ zone ++ "): N/A"
-
diff --git a/src/Plugins/Monitors/UVMeter.hs b/src/Plugins/Monitors/UVMeter.hs
index 5fa0b82..b0f5ac3 100644
--- a/src/Plugins/Monitors/UVMeter.hs
+++ b/src/Plugins/Monitors/UVMeter.hs
@@ -31,7 +31,7 @@ uvConfig = mkMConfig
        ["station"                               -- available replacements
        ]
 
-data UvInfo = UV { index :: String }
+newtype UvInfo = UV { index :: String }
     deriving (Show)
 
 uvURL :: String
@@ -86,7 +86,7 @@ runUVMeter (s:_) = do
 type AttrName  = String
 type AttrValue = String
 
-data Attribute = Attribute (AttrName, AttrValue)
+newtype Attribute = Attribute (AttrName, AttrValue)
     deriving (Show)
 
 data XML = Element String [Attribute] [XML]
diff --git a/src/Plugins/Monitors/Wireless.hs b/src/Plugins/Monitors/Wireless.hs
index b1e3c7e..26ded2d 100644
--- a/src/Plugins/Monitors/Wireless.hs
+++ b/src/Plugins/Monitors/Wireless.hs
@@ -19,7 +19,7 @@ import System.Console.GetOpt
 import Plugins.Monitors.Common
 import IWlib
 
-data WirelessOpts = WirelessOpts
+newtype WirelessOpts = WirelessOpts
   { qualityIconPattern :: Maybe IconPattern
   }
 
diff --git a/src/Window.hs b/src/Window.hs
index 3c3981e..11ea82e 100644
--- a/src/Window.hs
+++ b/src/Window.hs
@@ -1,7 +1,7 @@
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Window
--- Copyright   :  (c) 2011-16 Jose A. Ortega Ruiz
+-- Copyright   :  (c) 2011-17 Jose A. Ortega Ruiz
 --             :  (c) 2012 Jochen Keil
 -- License     :  BSD-style (see LICENSE)
 --
@@ -197,7 +197,7 @@ showWindow r c d w = do
 
 isMapped :: Display -> Window -> IO Bool
 isMapped d w = ism <$> getWindowAttributes d w
-    where ism (WindowAttributes { wa_map_state = wms }) = wms /= waIsUnmapped
+    where ism WindowAttributes { wa_map_state = wms } = wms /= waIsUnmapped
 
 borderOffset :: (Integral a) => Border -> Int -> a
 borderOffset b lw =
diff --git a/src/XUtil.hsc b/src/XUtil.hsc
index e63c9cb..9063147 100644
--- a/src/XUtil.hsc
+++ b/src/XUtil.hsc
@@ -1,7 +1,7 @@
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  XUtil
--- Copyright   :  (C) 2011, 2012, 2013, 2014, 2015 Jose Antonio Ortega Ruiz
+-- Copyright   :  (C) 2011, 2012, 2013, 2014, 2015, 2017 Jose Antonio Ortega Ruiz
 --                (C) 2007 Andrea Rossato
 -- License     :  BSD3
 --
@@ -11,8 +11,6 @@
 --
 -----------------------------------------------------------------------------
 
-{-# LANGUAGE ForeignFunctionInterface, EmptyDataDecls #-}
-
 module XUtil
     ( XFont
     , initFont
@@ -130,8 +128,7 @@ initXftFont :: Display -> String -> IO [AXftFont]
 initXftFont d s = do
   setupLocale
   let fontNames = wordsBy (== ',') (drop 4 s)
-  fonts <- mapM openFont fontNames
-  return fonts
+  mapM openFont fontNames
   where
     openFont fontName = do
         f <- openAXftFont d (defaultScreenOfDisplay d) fontName
@@ -160,7 +157,7 @@ textExtents (Core fs) s = do
 textExtents (Utf8 fs) s = do
   let (_,rl)  = wcTextExtents fs s
       ascent  = fi $ - (rect_y rl)
-      descent = fi $ rect_height rl + (fi $ rect_y rl)
+      descent = fi $ rect_height rl + fi (rect_y rl)
   return (ascent, descent)
 #ifdef XFT
 textExtents (Xft xftfonts) _ = do
@@ -185,8 +182,8 @@ printString d p (Utf8 fs) gc fc bc x y s a =
       io $ wcDrawImageString d p fs gc x y s
 
 #ifdef XFT
-printString dpy drw fs@(Xft fonts) _ fc bc x y s al = do
-  withDrawingColors dpy drw fc bc $ \draw -> \fc' -> \bc' -> do
+printString dpy drw fs@(Xft fonts) _ fc bc x y s al =
+  withDrawingColors dpy drw fc bc $ \draw fc' bc' -> do
     when (al == 255) $ do
       (a,d)  <- textExtents fs s
       gi <- xftTxtExtents' dpy fonts s
diff --git a/src/Xmobar.hs b/src/Xmobar.hs
index 5e44f62..c6e16a6 100644
--- a/src/Xmobar.hs
+++ b/src/Xmobar.hs
@@ -2,7 +2,7 @@
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Xmobar
--- Copyright   :  (c) 2011, 2012, 2013, 2014, 2015 Jose Antonio Ortega Ruiz
+-- Copyright   :  (c) 2011, 2012, 2013, 2014, 2015, 2017 Jose Antonio Ortega Ruiz
 --                (c) 2007 Andrea Rossato
 -- License     :  BSD-style (see LICENSE)
 --
@@ -107,7 +107,7 @@ startLoop xcfg@(XConf _ _ w _ _ _) sig vs = do
     eventLoop tv xcfg [] sig
   where
     handler thing (SomeException e) =
-      void $ putStrLn ("Thread " ++ thing ++ " failed: " ++ (show e))
+      void $ putStrLn ("Thread " ++ thing ++ " failed: " ++ show e)
     -- Reacts on events from X
     eventer signal =
       allocaXEvent $ \e -> do