Hello Steve, Monday, December 19, 2005, 10:42:19 PM, you wrote: SH> What I'm after is something like: SH> -- (psuedo-code) SH> [(b,c,d) | SH> b <- getDirectoryContents a_dir, SH> c <- getDirectoryContents (a_dir ++ "/" ++ b), SH> d <- getDirectoryContents (a_dir ++ "/" ++ b ++ "/" ++ c) ], this can't work because IO itself a monad, so "IO [a]" is two monads, and you can iterate only over external one, which is IO. instead: let foreach = flip mapM list <- foreach (getDirectoryContents a_dir) $ \b -> foreach (getDirectoryContents (a_dir ++ "/" ++ b)) $ \c -> foreach (getDirectoryContents (a_dir ++ "/" ++ b ++ "/" ++ c)) $ \d -> return (b,c,d) return $ concatMap $ concatMap list SH> This function isn't so clear at a glance, and yet what it's doing SH> seems like a pretty common thing to want to do: are there any library SH> functions for monads (or IO in particular) that make this sort of thing SH> easier, or should I to try and write my own function? Looks not too SH> difficult to write but I think I might miss something important if I didn't ask SH> first... How would you do it? if you just need to find all files recursively - use library http://hackage.haskell.org/packages/FilePath-0.1.0.tgz to manipulate filenames and function `doesDirectoryExist` to check that it is a directory. don't forget that `getDirectoryContents` returns list what contains names "." and ".." -- Best regards, Bulat mailto:bulatz@HotPOP.com