From a17c7f590f593cd5ec853ddf0ec48343b14621cf Mon Sep 17 00:00:00 2001
From: Heather <>
Date: Tue, 23 Sep 2014 08:13:00 +0200
Subject: version 0.0.1


diff --git a/Control/Concurrent/Reactive.hs b/Control/Concurrent/Reactive.hs
new file mode 100644
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+++ b/Control/Concurrent/Reactive.hs
@@ -0,0 +1,90 @@
+{-# LANGUAGE RankNTypes, GADTs, ScopedTypeVariables, LambdaCase #-}
+
+-- |
+-- Module: Data.Concurrent.Reactive
+-- Copyright: Andy Gill (??-2008), Heather Cynede (2014)
+-- License: BSD3
+-- |
+
+module Control.Concurrent.Reactive 
+	( Action
+	, Request
+	, reactiveObjectIO
+    , Sink
+    , pauseIO
+    , reactiveIO
+	) where
+
+import Control.Concurrent.Chan
+import Control.Concurrent
+import Control.Exception as Ex
+
+-- An action is an IO-based change to an explicit state
+type Action s    = s -> IO s	 -- only state change
+type Request s a = s -> IO (s,a) -- state change + reply to be passed back to caller
+
+-- This is the 'forkIO' of the O'Haskell Object sub-system.
+-- To consider; how do we handle proper exceptions?
+--   we need to bullet-proof this for exception!
+
+-- Choices:
+--   * do the Requests see the failure
+--   * Actions do not see anything
+--   * 
+data Msg s = Act (Action s)
+           | forall a . Req (Request s a) (MVar a)
+           | Done (MVar ())
+
+reactiveObjectIO
+    :: forall state object. state
+    -> (    ThreadId 
+            -> (forall r. Request state r -> IO r) 	-- requests
+            -> (Action state -> IO ()) 	            -- actions
+            -> IO ()				                -- done
+            -> object
+       )
+    -> IO object
+reactiveObjectIO state mkObject = do
+    chan <- newChan
+    -- We return the pid, so you can build a hard-abort function
+    -- we need to think about this; how do you abort an object
+    -- the state is passed as the argument, watch for strictness issues.
+    let dispatch state = 
+         readChan chan >>= \case Act act     -> do state1 <- act state
+                                                   dispatch $! state1
+                                 Req req box -> do (state1,ret) <- req state
+                                                   putMVar box ret
+                                                   dispatch $! state1
+                                 Done box    -> do putMVar box ()
+                                                   return () -- no looping; we are done
+    pid <- forkIO $ dispatch state
+
+    -- This trick of using a return MVar is straight from Johan's PhD.
+    let requestit :: forall r. Request state r -> IO r
+        requestit fun = do
+            ret <- newEmptyMVar
+            writeChan chan $ Req fun ret
+            takeMVar ret -- wait for the object to react
+        actionit act = writeChan chan $ Act act
+        doneit = do
+            ret <- newEmptyMVar
+            writeChan chan $ Done ret
+            takeMVar ret -- wait for the object to *finish*
+
+    return (mkObject pid requestit actionit doneit)
+
+-- From Conal; a Sink is a object into which things are thrown.
+type Sink a = a -> IO ()
+
+-- This turns a reactive style call into a pausing IO call.
+pauseIO :: (a -> Sink b -> IO ()) -> a -> IO b
+pauseIO fn a = do
+    var <- newEmptyMVar
+    forkIO $ do fn a (\ b -> putMVar var b)
+    takeMVar var
+
+-- This turns a pausing IO call into a reactive style call.
+reactiveIO :: (a -> IO b) -> a -> Sink b -> IO ()
+reactiveIO fn a sinkB = do
+    forkIO $ sinkB =<< fn a
+    return ()
diff --git a/LICENSE b/LICENSE
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+++ b/LICENSE
@@ -0,0 +1,25 @@
+Copyright (c) 2008 Andy Gill
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+1. Redistributions of source code must retain the above copyright
+   notice, this list of conditions and the following disclaimer.
+2. Redistributions in binary form must reproduce the above copyright
+   notice, this list of conditions and the following disclaimer in the
+   documentation and/or other materials provided with the distribution.
+3. The names of the authors may not be used to endorse or promote products
+   derived from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
+IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
diff --git a/Setup.hs b/Setup.hs
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index 0000000..9a994af
--- /dev/null
+++ b/Setup.hs
@@ -0,0 +1,2 @@
+import Distribution.Simple
+main = defaultMain
diff --git a/reactive-haskell.cabal b/reactive-haskell.cabal
new file mode 100644
index 0000000..ffd6ef3
--- /dev/null
+++ b/reactive-haskell.cabal
@@ -0,0 +1,16 @@
+Name:                reactive-haskell
+Version:             0.0.1
+
+Synopsis:            minimal fork of io-reactive
+Description:	     API for generating reactive objects
+Category:            Control, Reactivity
+
+License:             BSD3
+License-file:        LICENSE
+
+Author:              Andy Gill, Heather Cynede
+Maintainer:          Heather Cynede <heather@live.ru>
+
+Build-Depends:       base >= 4.3 && < 5
+Exposed-Modules:     Control.Concurrent.Reactive
+build-type: 	     Simple
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