1 files changed, 22 insertions, 2 deletions
diff --git a/src/Xmobar/System/Utils.hs b/src/Xmobar/System/Utils.hs
index 59c485c..33f221c 100644
--- a/src/Xmobar/System/Utils.hs
+++ b/src/Xmobar/System/Utils.hs
@@ -17,11 +17,16 @@
 ------------------------------------------------------------------------------
 
 
-module Xmobar.System.Utils (expandHome, changeLoop, onSomeException)
-where
+module Xmobar.System.Utils
+  ( expandHome
+  , changeLoop
+  , onSomeException
+  , safeIndex
+  ) where
 
 import Control.Monad
 import Control.Concurrent.STM
+import qualified Data.List.NonEmpty as NE
 
 import System.Environment
 import System.FilePath
@@ -50,3 +55,18 @@ onSomeException :: IO a -> (SomeException -> IO b) -> IO a
 onSomeException io what = io `catch` \e -> do _ <- what e
                                               throwIO (e :: SomeException)
 
+(!!?) :: [a] -> Int -> Maybe a
+(!!?) xs i
+    | i < 0     = Nothing
+    | otherwise = go i xs
+  where
+    go :: Int -> [a] -> Maybe a
+    go 0 (x:_)  = Just x
+    go j (_:ys) = go (j - 1) ys
+    go _ []     = Nothing
+{-# INLINE (!!?) #-}
+
+safeIndex :: NE.NonEmpty a -> Int -> a
+safeIndex xs index = case (NE.toList xs) !!? index of
+                       Nothing -> NE.head xs
+                       Just value -> value