use Win32-inotify

May mean the watcher works on Windows. Untested.

Utility/DirWatcher.hs

@@ -1,10 +1,10 @@
 {- generic directory watching interface
  -
- - Uses inotify, or kqueue, or fsevents to watch a directory
+ - Uses inotify, or kqueue, or fsevents, or win32-notify to watch a directory
  - (and subdirectories) for changes, and runs hooks for different
  - sorts of events as they occur.
  -
- - Copyright 2012 Joey Hess <joey@kitenet.net>
+ - Copyright 2012-2013 Joey Hess <joey@kitenet.net>
  -
  - Licensed under the GNU GPL version 3 or higher.
  -}
@@ -27,11 +27,15 @@ import Control.Concurrent
 import qualified Utility.FSEvents as FSEvents
 import qualified System.OSX.FSEvents as FSEvents
 #endif
+#if WITH_WIN32NOTIFY
+import qualified Utility.Win32Notify as Win32Notify
+import qualified System.Win32.Notify as Win32Notify
+#endif
 
 type Pruner = FilePath -> Bool
 
 canWatch :: Bool
-#if (WITH_INOTIFY || WITH_KQUEUE || WITH_FSEVENTS)
+#if (WITH_INOTIFY || WITH_KQUEUE || WITH_FSEVENTS || WITH_WIN32NOTIFY)
 canWatch = True
 #else
 #if defined linux_HOST_OS
@@ -47,7 +51,7 @@ canWatch = False
  - OTOH, with kqueue, often only one event is received, indicating the most
  - recent state of the file. -}
 eventsCoalesce :: Bool
-#if WITH_INOTIFY
+#if (WITH_INOTIFY || WITH_WIN32NOTIFY)
 eventsCoalesce = False
 #else
 #if (WITH_KQUEUE || WITH_FSEVENTS)
@@ -68,7 +72,7 @@ eventsCoalesce = undefined
  - still being written to, and then no add event will be received once the
  - writer closes it. -}
 closingTracked :: Bool
-#if (WITH_INOTIFY || WITH_FSEVENTS)
+#if (WITH_INOTIFY || WITH_FSEVENTS || WITH_WIN32NOTIFY)
 closingTracked = True
 #else
 #if WITH_KQUEUE
@@ -83,7 +87,7 @@ closingTracked = undefined
  - Fsevents generates events when an existing file is reopened and rewritten,
  - but not necessarily when it's opened once and modified repeatedly. -}
 modifyTracked :: Bool
-#if (WITH_INOTIFY || WITH_FSEVENTS)
+#if (WITH_INOTIFY || WITH_FSEVENTS || WITH_WIN32NOTIFY)
 modifyTracked = True
 #else
 #if WITH_KQUEUE
@@ -119,27 +123,35 @@ watchDir :: FilePath -> Pruner -> WatchHooks -> (IO FSEvents.EventStream -> IO F
 watchDir dir prune hooks runstartup =
 	runstartup $ FSEvents.watchDir dir prune hooks
 #else
+#if WITH_WIN32NOTIFY
+type DirWatcherHandle = Win32Notify.WatchManager
+watchDir :: FilePath -> Pruner -> WatchHooks -> (IO Win32Notify.WatchManager -> IO Win32Notify.WatchManager) -> IO DirWatcherHandle
+watchDir dir prune hooks runstartup =
+	runstartup $ Win32Notify.watchDir dir prune hooks
+#else
 type DirWatcherHandle = ()
 watchDir :: FilePath -> Pruner -> WatchHooks -> (IO () -> IO ()) -> IO DirWatcherHandle
 watchDir = undefined
 #endif
 #endif
 #endif
+#endif
 
-#if WITH_INOTIFY
 stopWatchDir :: DirWatcherHandle -> IO ()
+#if WITH_INOTIFY
 stopWatchDir = INotify.killINotify
 #else
 #if WITH_KQUEUE
-stopWatchDir :: DirWatcherHandle -> IO ()
 stopWatchDir = killThread
 #else
 #if WITH_FSEVENTS
-stopWatchDir :: DirWatcherHandle -> IO ()
 stopWatchDir = FSEvents.eventStreamDestroy
 #else
-stopWatchDir :: DirWatcherHandle -> IO ()
+#if WITH_WIN32NOTIFY
+stopWatchDir = Win32Notify.killWatchManager
+#else
 stopWatchDir = undefined
 #endif
 #endif
 #endif
+#endif

Utility/Win32Notify.hs

@@ -11,32 +11,33 @@ import Common hiding (isDirectory)
 import Utility.DirWatcher.Types
 
 import System.Win32.Notify
+import qualified System.PosixCompat.Files as Files
 
 watchDir :: FilePath -> (FilePath -> Bool) -> WatchHooks -> IO WatchManager
 watchDir dir ignored hooks = do
 	scan dir
 	wm <- initWatchManager
 	void $ watchDirectory wm dir True [Create, Delete, Modify, Move] handle
-	retufn wm
+	return wm
   where
 	handle evt
 		| ignoredPath ignored (filePath evt) = noop
-		| otherwise = case eventToVariety evt of
+		| otherwise = case evt of
-			Delete
+			(Deleted _ _)
 				| isDirectory evt -> runhook delDirHook Nothing
 				| otherwise -> runhook delHook Nothing
-			Create
+			(Created _ _)
 				| isDirectory evt -> noop
 				| otherwise -> runhook addHook Nothing
-			Modify
+			(Modified _ _)
 				| isDirectory evt -> noop
 				{- Add hooks are run when a file is modified for 
 				 - compatability with INotify, which calls the add
 				 - hook when a file is closed, and so tends to call
 				 - both add and modify for file modifications. -}
 				| otherwise -> do
-					runHook addHook Nothing
+					runhook addHook Nothing
-					runHook modifyHook Nothing
+					runhook modifyHook Nothing
 	  where
 		runhook h s = maybe noop (\a -> a (filePath evt) s) (h hooks)