preparing some classes

affection.cabal

@@ -45,6 +45,7 @@ library
                      -- , Affection.Actor
                      -- , Affection.Animation
                      , Affection.Util
+                     , Affection.MessageBus
   default-extensions:  OverloadedStrings
 
   -- Modules included in this library but not exported.
@@ -73,6 +74,7 @@ library
                      , glib
                      , bytestring
                      , OpenGL
+                     , stm
                      -- , sdl2-image
 
 -- executable example00

src/Affection.hs

@@ -41,6 +41,7 @@ import Affection.MouseInteractable as A
 -- import Affection.Actor as A
 -- import Affection.Animation as A
 import Affection.Util as A
+import Affection.MessageBus as A
 
 import Graphics.Rendering.OpenGL as GL (clear, flush, ClearBuffer(..))
 

src/Affection/MessageBus.hs

@@ -1,4 +1,22 @@
 module Affection.MessageBus where
 
-class MessageBus a where
+import Control.Concurrent.STM as STM
 
+import Data.IORef
+
+class Message msg where
+  msgPayload :: msg -> Maybe a
+
+type Channel msg = TChan msg
+
+class Participant prt where
+  partChannel        :: (Message msg) => prt -> IORef (Channel msg)
+
+  partConnectChannel :: (Message msg) => prt -> (Channel msg) -> IO ()
+
+  partListen         :: (Message msg) => prt -> IO msg
+
+  partBroadcast      :: (Message msg) => prt -> msg -> IO ()
+
+newBroadcastChannel :: IO (Channel msg)
+newBroadcastChannel = atomically $ newBroadcastTChan