1 module Miscutils where

     2 

     3 import IO

     4 import System.IO

     5 import Control.Concurrent

     6 import Control.Concurrent.STM

     7 import Control.Exception (finally)

     8 

     9 sendMsg :: Handle -> String -> IO()

    10 sendMsg clientHandle str = finally (return ()) (hPutStrLn clientHandle str >> hFlush clientHandle) -- catch exception when client tries to send to other

    11 

    12 sendAll :: [Handle] -> String -> IO[()]

    13 sendAll clientsList str = mapM (\x -> sendMsg x str) clientsList

    14 

    15 sendOthers :: [Handle] -> Handle -> String -> IO[()]

    16 sendOthers clientsList clientHandle str = sendAll (filter (/= clientHandle) clientsList) str

    17 

    18 extractCmd :: String -> (String, [String])

    19 extractCmd str = if ws == [] then ("", []) else (head ws, tail ws)

    20 		where ws = words str

    21 

    22 manipState :: TVar[a] -> ([a] -> [a]) -> IO()

    23 manipState state op =

    24 	atomically $ do

    25 			ls <- readTVar state

    26 			writeTVar state $ op ls

    27