On Mon, Oct 25, 2004 at 09:42:13PM +0000, John Goerzen wrote:
Maybe I misunderstood something ... but why do you need to read from the stream multiple times after calling hGetContents? The function returns the _entire_ (lazily evaluated) input stream, there is no need to read again. You already _have_ everything.
Because I'd have to use a state monad or something to chop off the top of the list each time I read from it. This is a FTP client module, so, for instance, you might see this session:
cwd h "/pub/linuc" nlst h Nothing
etc.
Each command sends something and reads a reply. "h" holds an instance of that data structure I posted.
If I just try to read from the list during each command, I would just read the same (first) response over and over again. Or, I'd have to store a position (which also requires a state monad), which would lead to wasting memory keeping all that stuff around.
Sounds to me like you really want to be putting the code doing this inside of the IO monad. It is interacting with the outside world, and maintaining state at that... Dave