Add getDirectoryContents' which ignores "." and ".."

haskell · Sep 25, 2015 · 7691e8a · 7691e8a
1 parent ce5ae1f
commit 7691e8a
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diff --git a/System/Directory.hs b/System/Directory.hs
@@ -30,6 +30,7 @@ module System.Directory
     , removeDirectoryRecursive
     , renameDirectory
     , getDirectoryContents
+    , getDirectoryContents'
     -- ** Current working directory
     , getCurrentDirectory
     , setCurrentDirectory
@@ -1030,6 +1031,15 @@ getDirectoryContents path =
                  -- no need to reverse, ordering is undefined
 #endif /* mingw32 */
 
+{- | A version of 'getDirectoryContents' which ignores @.@ and @..@
+current and parent directories.
+
+-}
+getDirectoryContents' :: FilePath -> IO [FilePath]
+getDirectoryContents' path =
+  (filter f) <$> (getDirectoryContents path)
+  where f filename = filename /= "." && filename /= ".."
+
 #endif /* __GLASGOW_HASKELL__ */
 
 

diff --git a/tests/GetDirContents001.hs b/tests/GetDirContents001.hs
@@ -11,10 +11,12 @@ main :: TestEnv -> IO ()
 main _t = do
   createDirectory dir
   T(expectEq) () specials . sort =<< getDirectoryContents dir
+  T(expectEq) () [] . sort =<< getDirectoryContents' dir
   names <- for [1 .. 100 :: Int] $ \ i -> do
     let name = 'f' : show i
     writeFile (dir </> name) ""
     return name
   T(expectEq) () (sort (specials <> names)) . sort =<< getDirectoryContents dir
+  T(expectEq) () (sort (names)) . sort =<< getDirectoryContents' dir
   where dir      = "dir"
         specials = [".", ".."]