-- Hoogle documentation, generated by Haddock
-- See Hoogle, http://www.haskell.org/hoogle/


-- | Lightweight Erlang-style actors for Haskell.
--   
--   Hactor is a library which aims to provide lightweight Erlang-style
--   actors for Haskell.
@package hactor
@version 1.0.0.0


-- | This module implements Erlang-style actors (what Erlang calls
--   processes).
--   
--   @
module Control.Concurrent.Actor

-- | An <a>ActorHandle</a> acts as a reference to a specific actor.
data ActorMessage msg => ActorHandle msg

-- | The <a>ActorMessage</a> class must be implemented by any type that
--   will be sent as a message to actors. Any given type of actor will have
--   one <a>ActorMessage</a> type that is sent to that actor. This ensures
--   type safety. Currently this is simply a dummy class with nothing in
--   it, but things may be added in the future.
class ActorMessage msg

-- | The base actor monad.
type ActorM msg = ReaderT (ActorContext msg) IO

-- | Sends a message to the given actor handle. This is secretly just
--   <a>sendIO</a> lifted into an actor monad.
send :: (ActorMessage msg, ActorMessage msg') => ActorHandle msg -> msg -> ActorM msg' ()

-- | Sends a message to the given actor handle from within the IO monad.
sendIO :: ActorMessage msg => ActorHandle msg -> msg -> IO ()

-- | Reads a message from the actor's mail box. If there are no messages,
--   blocks until one is received. If you don't want this, use
--   <a>receiveMaybe</a> instead.
receive :: ActorMessage msg => ActorM msg (msg)

-- | Reads a message from the actor's mail box. If there are no messages,
--   returns <a>Nothing</a>.
receiveMaybe :: ActorMessage msg => ActorM msg (Maybe msg)

-- | Spawns the given actor on another thread and returns a handle to it.
spawnActor :: ActorMessage msg => ActorM msg () -> IO (ActorHandle msg)

-- | Runs the given actor on the current thread. This function effectively
--   turns the current thread into the actor's thread. Obviously, this
--   means that this function will block until the actor exits. You
--   probably want to use this for your "main" actor.
runActor :: ActorMessage msg => ActorM msg () -> IO ()

-- | Gets a handle to the current actor.
self :: ActorMessage msg => ActorM msg (ActorHandle msg)

-- | Gets the thread ID for the given actor handle.
actorThread :: ActorMessage msg => ActorHandle msg -> ThreadId
instance ActorMessage ()