LIB: improve exception handling

src/HSFM/FileSystem/Errors.hs

@@ -199,6 +199,15 @@ catchErrno en a1 a2 =
       else ioError e
 
 
+-- |Execute the given action and retrow IO exceptions that have the given errno.
+rethrowErrnoAs :: Errno         -- ^ errno to catch
+               -> FmIOException -- ^ rethrow as
+               -> IO a          -- ^ action to try
+               -> IO a
+rethrowErrnoAs en fmex action = catchErrno en action (throw fmex)
+
+
+
 -- |Like `catchIOError`, with arguments swapped.
 handleIOError :: (IOError -> IO a) -> IO a -> IO a
 handleIOError a1 a2 = catchIOError a2 a1

src/HSFM/FileSystem/FileType.hs

@@ -52,6 +52,10 @@ import Data.Time.Clock.POSIX
   , posixSecondsToUTCTime
   )
 import Data.Time()
+import Foreign.C.Error
+  (
+    eACCES
+  )
 import HPath
     (
       Abs
@@ -60,6 +64,7 @@ import HPath
     , pattern Path
     )
 import qualified HPath as P
+import HSFM.FileSystem.Errors
 import HSFM.Utils.MyPrelude
 import Prelude hiding(readFile)
 import System.IO.Error
@@ -608,7 +613,8 @@ getDirsFiles' :: (Path Fn -> [Path Fn] -> [Path Fn]) -- ^ filter function
               -> Path Abs                            -- ^ dir to read
               -> IO [Path Fn]
 getDirsFiles' filterf fp =
-  bracket (PFD.openDirStream . P.toFilePath $ fp)
+  rethrowErrnoAs eACCES (Can'tOpenDirectory . P.fpToString . P.fromAbs $ fp)
+  $ bracket (PFD.openDirStream . P.toFilePath $ fp)
           PFD.closeDirStream
           $ \dirstream ->
             let mdirs :: [Path Fn] -> IO [Path Fn]