module Effectful.Timeout
  ( -- * Effect
    Timeout

    -- ** Handlers
  , runTimeout

    -- ** Operations
  , timeout
  ) where

import qualified System.Timeout as T

import Effectful
import Effectful.Dispatch.Static

-- | An effect for timing out computations.
data Timeout :: Effect

type instance DispatchOf Timeout = Static WithSideEffects
data instance StaticRep Timeout = Timeout

-- | Run the 'Timeout' effect.
runTimeout :: IOE :> es => Eff (Timeout : es) a -> Eff es a
runTimeout :: forall (es :: [Effect]) a.
(IOE :> es) =>
Eff (Timeout : es) a -> Eff es a
runTimeout = forall (e :: Effect) (sideEffects :: SideEffects) (es :: [Effect])
       a.
(DispatchOf e ~ 'Static sideEffects, MaybeIOE sideEffects es) =>
StaticRep e -> Eff (e : es) a -> Eff es a
evalStaticRep StaticRep Timeout
Timeout

-- | Lifted 'T.timeout'.
timeout
  :: Timeout :> es
  => Int
  -- ^ The timeout in microseconds (1/10^6 seconds).
  -> Eff es a
  -- ^ The computation the timeout applies to.
  -> Eff es (Maybe a)
timeout :: forall (es :: [Effect]) a.
(Timeout :> es) =>
Int -> Eff es a -> Eff es (Maybe a)
timeout = forall a b (es :: [Effect]).
HasCallStack =>
(IO a -> IO b) -> Eff es a -> Eff es b
unsafeLiftMapIO forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall a. Int -> IO a -> IO (Maybe a)
T.timeout