Hello Joel, Tuesday, December 13, 2005, 3:04:11 PM, you wrote: JR> How is your library licensed? is costs many megabucks because it's very complex proprietary design where some functions reach whole 12 lines! :) of course, you can do what you want with this library. may be the better way is to write your won, stealing one ot two ideas from mine you can find another interesting works in: http://www-i2.informatik.rwth-aachen.de/~stolz/Haskell/CA.hs http://www-i2.informatik.rwth-aachen.de/Research/distributedHaskell/pbdhs-20... (this one seems to be especially interesting for you, providing "ports" - i think, in Erlang style) http://www-i2.informatik.rwth-aachen.de/Research/distributedHaskell/network.... http://quux.org/devel/missingh/missingh_0.12.0.tar.gz (see Logging, Network, Threads directories) JR> How can a process maintain internal state? process in my lib is just an ordinary Haskell function and therefore this is done as in any other Haskell functions :) my examples are easified - to not bother with EOF i just organized in each process a loop which sends and/or receives just 10 messages. in my real program data sent between process are defined by structures like this: data Message = FileStarted String | FileData String | DataEnd so typical communication scenario is: sendP h (FileStart "1") ; sendP h (FileData "abc") ; sendP h (FileData "def") ; sendP h (FileData "ghi") sendP h (FileStart "2") ; sendP h (FileData "qwer") sendP h (FileStart "3") ; sendP h (FileData "123") sendP h DataEnd and each function realizing process finishes only when this process is done. sender process organizes cycle which reads files and sends their data to the channel. receiver process organizes cycle until `DataEnd` is received in one phrase, it's just the same organization as in your own program :))) JR> How would I use your library to code a socket reader/writer that JR> writes received events to the socket and propagates back anything JR> that is received? JR> The producer/consumer in front of this network client would be JR> another process that analyzes the events sent back to it and produces JR> events based on the analysis. i don't understand your questions JR> How would I use it to launch a few network clients that seat there JR> and process events until they decided to quit? The whole program JR> needs to stay up until the last network client has exited. JR> The pipeline to me looks like this: JR> <-> Bot <-> Socket client ... Server JR> / JR> Bot launcher --- <-> Bot <-> Socket client ... Server JR> \ JR> <-> Bot <-> Socket client ... Server JR> Where bot launcher starts a predefined # of bots and collects results JR> sent back by each one. my lib is not appropriate for yor task, because it is oriented to easify creation of processes which have only one input. but your main thread must receive data from all bots, and bot must receive data from two sources. the decision depends on the strategy of mixing these inputs - will it be fair FIFO or more advanced schema? if it's a FIFO then something like this (i'm skipped only exceptions processing and creating socket-reader process inside of each bot - writing to socket must be performed by bot itself): {-# OPTIONS_GHC -cpp #-} import Control.Concurrent import Control.Exception import Control.Monad import Data.Array import Data.Char import Data.Either import Data.HashTable import Data.IORef import Data.List import Data.Maybe import Data.Word import Debug.Trace import Foreign.C.String import Foreign.Marshal.Alloc import Foreign.Marshal.Array import Foreign.Marshal.Pool import Foreign.Marshal.Utils import Foreign.Ptr import Text.Regex import System.IO.Unsafe ----------------------------------------------------------------- --- Bot launcher implementation --------------------------------- ----------------------------------------------------------------- main = do (sendToMain, receiveFromBots) <- createChannel bots <- foreach [1..10] $ createProcess . bot sendToMain mapM_ (`sendToProcess` "Wake up, Neo!") bots while receiveFromBots (/="I want to stop the Matrix!") print -- .... mapM_ killProcess bots -- or, if you are more humane - "mapM_ waitProcessDie bots" :) ----------------------------------------------------------------- --- Bot implementation ------------------------------------------ ----------------------------------------------------------------- bot sendToMain n receiveMessagesForMe = do forever $ do x <- receiveMessagesForMe case x of "Wake up, Neo!" -> sendToMain$ show n++": I'm not sleeping!" "Are you wanna coffee?" -> sendToMain$ show n++": Yes, it is!" yield sendToMain "I want to stop the Matrix!" ----------------------------------------------------------------- --- Process implementation details ------------------------------ ----------------------------------------------------------------- -- |Abstract type for all of our processes data Process a = Process { pid :: ThreadId , sender :: a -> IO () -- action which must be used to send sata to this process , finished :: MVar () -- filled when this process is finisjed } -- Operations on processes -- |Create process and return structure Process to communicate with it -- The `process` function given are called with a parameter, which -- represent an action which must be used by process to receive it's -- data createProcess process = do finished <- newEmptyMVar (sendToMe, receiveMessagesForMe) <- createChannel pid <- forkIO $ do process receiveMessagesForMe `finally` putMVar finished () return Process { pid = pid , sender = sendToMe , finished = finished } killProcess = killThread.pid waitProcessDie = readMVar.finished sendToProcess = sender ----------------------------------------------------------------- --- Channel implementation details ------------------------------ ----------------------------------------------------------------- #if 1 -- Channels implemented via MVar createChannel = do c <- newEmptyMVar return (putMVar c, takeMVar c) #else -- Channels implemented via Chan createChannel = do c <- newChan return (writeChan c, readChan c) #endif ----------------------------------------------------------------- --- Random utility functions ------------------------------------ ----------------------------------------------------------------- while inp cond out = do x <- inp if (cond x) then do out x while inp cond out else return x forever action = do action forever action foreach = flip mapM JR> I think your library looks a bit like Yampa in that your processes JR> are somewhat like signal functions. yes, it is close things - data-driven execution and signal processing -- Best regards, Bulat mailto:bulatz@HotPOP.com