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{-# LANGUAGE MultiParamTypeClasses, FunctionalDependencies #-}
-- TODO: ADD Unsafe
-- | Unsafe operations. NOT part of "Safe Haskell".
--
-- These are "unsafe" (in the normal, Haskell sense) when used with a
-- "runPar" of type `Par a -> a`. If used with a `runParIO` that
-- stays in the IO monad, then they are simply dangerous.
--
-- For the purposes of Safe Haskell, any module that imports this
-- module becomes untrustworthy.
module Control.Monad.Par.Unsafe
(
ParUnsafe(..)
)
where
-- import Control.Monad.Par.Class
-- | The class of Par monads that provide unsafe functionality.
class ParUnsafe iv p | p -> iv where
-- | Peek at the current contents of an 'IVar' in a nonblocking way.
unsafePeek :: iv a -> p (Maybe a)
-- | Attempt to put a value into an 'IVar'. If successful, return the
-- value put. If something is already there, return it instead.
unsafeTryPut :: iv a -> a -> p a
-- | Lift an 'IO' operation into the Par monad.
unsafeParIO :: IO a -> p a
-- Aside:
-- If the need ever arises we could also consider unsafeMultiplePut that
-- would be able to change the current value of an IVar. It could
-- cause big problems in the distributed case, however.
|
