ENH use nix

app/Main.hs

@@ -25,11 +25,10 @@
 
 module Main (main) where
 
-import           Control.Monad             (forM_, forever, void, when)
+import           Control.Monad
 import           Control.Monad.Reader
 import           Control.Monad.State
 
-import           Data.List                 (any)
 import           Data.Maybe                (isJust)
 
 import           Graphics.X11.Types
@@ -97,6 +96,7 @@ parse ("-t":t:b:rs) = initXMan rs $ mkXcapeProcess (Just t) b
 parse (b:rs)        = initXMan rs $ mkXcapeProcess Nothing b
 parse _             = usage
 
+-- | The name of the xcape executable
 xcapeExe :: String
 xcapeExe = "xcape"
 
@@ -141,11 +141,10 @@ initXMan rs cp = do
           updateXCape -- set the initial state before entering main loop
           forever $ handle =<< io (nextEvent dpy e >> getEvent e)
 
+-- | Return true if xcape is installed
 checkXcape :: IO Bool
 checkXcape = isJust <$> findExecutable xcapeExe
 
-
-
 -- | Lift an IO monad into the XMan context
 io :: MonadIO m => IO a -> m a
 io = liftIO

stack.yaml

@@ -17,7 +17,7 @@
 #
 # resolver: ./custom-snapshot.yaml
 # resolver: https://example.com/snapshots/2018-01-01.yaml
-resolver: lts-14.12
+resolver: lts-16.31
 
 # User packages to be built.
 # Various formats can be used as shown in the example below.
@@ -64,3 +64,11 @@ packages:
 #
 # Allow a newer minor version of GHC than the snapshot specifies
 # compiler-check: newer-minor
+nix:
+  enable: true
+  packages:
+    - xorg.libxcb
+    - xorg.libXrender
+    - xorg.libXrandr
+    - xorg.libXScrnSaver
+    - xorg.libXext