ebooks or books required ..

[neokewl]

Hi all,

I am thinking of developing a simple chat program using a client server architecture using haskell. Currently the books tht i have focus on the fundamentals of the language and the inbuilt functions.

I would like to know if there are libraries for networking operations and for that of gui. Also, I would appreciate if some one could give me a link to a resource that focuses on these aspects.


thnx
neokewl

[haskell]

Use Google instead of asking... There aren't many functional programmers, and even less using Haskell.

If you can't find it, then go to the Haskell mailing list on Usenet.

[neokewl]

n wot makes u feel tht i havent googled it before shooting a mail across.

I thought this was a functional programming group, n ppl in here should be learning or learnt or serious about functional programming.

So I think it is right for me to put a valid question to a correct group tht i have registered to. If u dont knw the answer then its fine, but it is not courteous of u too shoot the mails like the above as u did.

[Hikaru79]

neokewl @ Fri Jan 05, 2007 5:14 pm wrote:

n wot makes u feel tht i havent googled it before shooting a mail across.

Not to seem rude or anything, but probably the fact that you didn't find anything. For example, here's the second hit when searching for "haskell networking": a tutorial on building an IRC bot in Haskell. I've only skimmed it, but it seems like a good introduction to basic network i/o.

And when I googled "haskell gui", the very top hit was a page with links to two different toolkits here. And the second hit is an actual Wikibook on getting those set up, here

See?

[haskell]

Exactly. I found all sorts of things with simple searches.

And you don't exactly make the most sense. With all the spelling errors and such... Maybe you spelled something wrong(just throwing it out there).

Plus this isn't a mailing list. It is a message board. The mailing lists are much more indepth with the "experts" around there that are 100% focused on one particular language.

If you don't want the greatest help you can be given(told to go to a mailing list where the people are 100% dedicated to a language) than fine. I don't care.

[rizzix]

Here's a chat server i wrote in haskell long time ago... (It dosen't use any fancy STM.. so it should be easy to follow)

Haskell:

import System.IO import Network import Control.Concurrent import Control.Concurrent.MVar type Peer = (Handle, HostName, PortNumber) data Message    = Msg Peer [Peer] String | Notice Peer [Peer] NoticeType data NoticeType = Connected              | Disconnected instance Show Message where     show (Msg (_,h,p) _ str) = "MESSAGE " ++ h ++ ":" >++ show p >++ " " >++ str     show (Notice (_,h,p) _ Connected) = "CONNECTED " ++ h ++ ":" >++ show p     show (Notice (_,h,p) _ Disconnected) = "DISCONNECTED " ++ h ++ ":" >++ show p -- the server's PortNumber conn_port >:: PortID conn_port = PortNumber 8090 -- setup server, fork dispatch thread and wait for clients main >:: IO () main = withSocketsDo $ do     server_sock <- listenOn conn_port     cont_var    <- newMVar True     clients_var <- newMVar [] >:: IO (MVar [Peer])     msg_var     <- newEmptyMVar >:: IO (MVar Message)     _ <- forkIO $ while cont_var $ dispatchMessages msg_var     while cont_var $ waitForClients cont_var msg_var server_sock clients_var -- while cont_var $ do stuff... while >:: MVar Bool -> IO () -> IO () while cont_var process = do     cont <- readMVar cont_var     case cont of         True  -> process >> while cont_var process         False -> return () -- dispatch message in buffer to all clients dispatchMessages >:: MVar Message -> IO () dispatchMessages msg_var = do     msg <- takeMVar msg_var     case msg of         Notice p pz Connected -> p `reveal` pz >> tellAll pz (show msg)         _                     -> tellAll (peers msg) (show msg)   where tellAll _  [] = return ()         tellAll [] _  = return ()         tellAll ((h,_,_):cs) msg = hPutStrLn h msg >> tellAll cs msg                 reveal _  []  = return ()         reveal c@(h,_,_) (p:pz) = do             hPutStrLn h $ show $ Notice p (c:pz) Connected             reveal c pz                 peers (Msg _ cs _) = cs         peers (Notice _ cs _) = cs -- for each client spawn a new thread and proccess requests waitForClients >:: MVar Bool -> MVar Message -> Socket -> MVar [Peer] -> IO () waitForClients cont_var msg_var server_socket clients_var = do     c@(h,_,_) <- accept server_socket     hSetBuffering h LineBuffering     modifyMVar_ clients_var (registerWithClients c)     _ <- forkIO $ processClient cont_var msg_var c clients_var     return ()     where registerWithClients c cs = do               putMVar msg_var (Notice c cs Connected)               return (c:cs) -- each client is proccessed in an endless loop until "BYE" processClient >:: MVar Bool -> MVar Message -> Peer -> MVar [Peer] -> IO () processClient cont_var msg_var c@(h, host, port) clients_var = do     cont <- readMVar cont_var     case cont of         True -> do             line <- hGetLine h             ccs <- readMVar clients_var             let cs = filter (/=c) ccs             case line of                 ('B':'Y':'E':_) -> do                     hClose h                     modifyMVar_ clients_var (\_ -> return cs)                     putMVar msg_var (Notice c cs Disconnected)                     testQuitServer cs                 _  -> do                     putMVar msg_var (Msg c cs line)                     processClient cont_var msg_var c clients_var         _ -> return ()   where testQuitServer [] = do modifyMVar_ cont_var (\_ -> return False)                                h <- connectTo "localhost" conn_port                                hClose h         testQuitServer _  = return ()

You can telnet to it and test it out

Oh and ignore the '>' character before the '::' in the type definitions.. It is a marker Dan had applied to debug the syntax script.