On Fri, 2008-01-11 at 20:20 -0200, Andre Nathan wrote:
Both versions which use getDirectoryContents also use much more memory than the one which uses readDirStream (about 8M vs about 2M). Maybe I'm not exploting getDirectoryContents' laziness correctly? I expected the second and third versions to run in about the same time.
Forgot to paste the code... foo :: IO () foo = do entries <- getDirectoryContents "." let procs = filter (=~ "^[0-9]+$") entries mapM_ putStrLn procs processEntry :: DirStream -> IO () processEntry ds = do entry <- readDirStream ds if entry =~ "^[0-9]+$" then do putStrLn entry processEntry ds else if entry == "" then return () else processEntry ds bar :: IO () bar = do ds <- openDirStream "." processEntry ds closeDirStream ds processEntry' :: FilePath -> IO () processEntry' entry = do if entry =~ "^[0-9]+$" then putStrLn entry else return () baz :: IO () baz = do entries <- getDirectoryContents "." mapM_ processEntry' entries main = forM_ [1..1000] $ \_ -> foo {- bar -} {- baz -}