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


-- | Packaging of 'WaitHandle', extracted from Max Bolingbroke's OpenShake. Wait
handles are MVars which can only be written to once, and from which values
can never be removed.
--   
@package wait-handle
@version 0.1

module Control.Concurrent.MVar.WaitHandle

-- | A <a>WaitHandle</a> is basically just an <a>MVar</a> that can only be
--   put into once, and then never gets anything removed from it
data WaitHandle a
newWaitHandle :: IO (WaitHandle a, a -> IO ())
waitOnWaitHandle :: WaitHandle a -> IO a

-- | Looks ahead to see if the caller is likely to have to wait on the wait
--   handle. If this function returns <a>True</a> then they may or may not
--   actually have to wait, but if the function returns <a>False</a> then
--   they certainly won't have to wait.
mayWaitOnWaitHandle :: WaitHandle a -> IO Bool
instance Functor WaitHandle
instance Show (WaitHandle a)
instance Eq (WaitHandle a)