Alt.hs

-- Communicating Haskell Processes.
-- Copyright (c) 2008-2010, University of Kent, Neil Brown.
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-- | A module containing the choice constructs.  See <http://chplib.wordpress.com/2010/04/20/automatic-model-generation-part-3-choice-and-io/>
-- for details of how choice is modelled.
--
-- Currently conjunction is not modelled (mainly because CSP\/FDR don't support
-- it), but external choice is modelled fine; 'priAlt' is modelled as a plain 'alt',
-- though.
module Control.Concurrent.CHPSpec.Alt (alt, (<->), priAlt, (</>)) where

import Control.Concurrent.CHPSpec.Base
import Control.Concurrent.CHPSpec.Spec

alt :: [CHP a] -> CHP a
alt = priAlt

priAlt :: [CHP a] -> CHP a
priAlt [] = stopSpecT $ return Stop
priAlt ps = altSpecT ps

(<->) :: CHP a -> CHP a -> CHP a
(<->) a b = alt [a,b]
  
(</>) :: CHP a -> CHP a -> CHP a
(</>) a b = priAlt [a,b]

infixl </>
infixl <->