Add Control.Effect.Exception.

main
Patrick Thomson 2019-10-29 12:22:20 -04:00
parent 65fa041be3
commit a39a61861d
2 changed files with 260 additions and 0 deletions

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packages: .
source-repository-package
type: git
location: https://github.com/fused-effects/fused-effects.git
tag: 0c7d9c19b638f7fe21ac77903894308ad15b0e80

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{-# LANGUAGE DeriveFunctor, ExistentialQuantification, RankNTypes, StandaloneDeriving #-}
-- | Operations from "Control.Exception" lifted into effectful contexts using 'Control.Effect.Lift.Lift'.
--
-- @since 1.0.0.0
module Control.Effect.Exception
( -- * Lifted "Control.Exception" operations
throwIO
, ioError
, throwTo
, catch
, catches
, Handler(..)
, catchJust
, handle
, handleJust
, try
, tryJust
, evaluate
, mask
, mask_
, uninterruptibleMask
, uninterruptibleMask_
, getMaskingState
, interruptible
, allowInterrupt
, bracket
, bracket_
, bracketOnError
, finally
, onException
, module Control.Exception
-- * Lift effect
, Lift(..)
, sendM
, liftWith
-- * Re-exports
, Algebra
, Has
, run
) where
import Control.Concurrent (ThreadId)
import Control.Effect.Lift
import Control.Exception hiding
( throwIO
, ioError
, throwTo
, catch
, catches
, Handler
, catchJust
, handle
, handleJust
, try
, tryJust
, evaluate
, mask
, mask_
, uninterruptibleMask
, uninterruptibleMask_
, getMaskingState
, interruptible
, allowInterrupt
, bracket
, bracket_
, bracketOnError
, finally
, onException
)
import qualified Control.Exception as Exc
import Prelude hiding (ioError)
-- | See @"Control.Exception".'Exc.throwIO'@.
--
-- @since 1.0.0.0
throwIO :: (Exc.Exception e, Has (Lift IO) sig m) => e -> m a
throwIO = sendM . Exc.throwIO
-- | See @"Control.Exception".'Exc.ioError'@.
--
-- @since 1.0.0.0
ioError :: Has (Lift IO) sig m => IOError -> m a
ioError = sendM . Exc.ioError
-- | See @"Control.Exception".'Exc.throwTo'@.
--
-- @since 1.0.0.0
throwTo :: (Exc.Exception e, Has (Lift IO) sig m) => ThreadId -> e -> m ()
throwTo thread = sendM . Exc.throwTo thread
-- | See @"Control.Exception".'Exc.catch'@.
--
-- @since 1.0.0.0
catch :: (Exc.Exception e, Has (Lift IO) sig m) => m a -> (e -> m a) -> m a
catch m h = liftWith $ \ ctx run -> run (m <$ ctx) `Exc.catch` (run . (<$ ctx) . h)
-- | See @"Control.Exception".'Exc.catches'@.
--
-- @since 1.0.0.0
catches :: Has (Lift IO) sig m => m a -> [Handler m a] -> m a
catches m hs = liftWith $ \ ctx run ->
Exc.catches (run (m <$ ctx)) (map (\ (Handler h) -> Exc.Handler (run . (<$ ctx) . h)) hs)
-- | See @"Control.Exception".'Exc.Handler'@.
--
-- @since 1.0.0.0
data Handler m a
= forall e . Exc.Exception e => Handler (e -> m a)
deriving instance Functor m => Functor (Handler m)
-- | See @"Control.Exception".'Exc.catchJust'@.
--
-- @since 1.0.0.0
catchJust
:: (Exc.Exception e, Has (Lift IO) sig m)
=> (e -> Maybe b)
-> m a
-> (b -> m a)
-> m a
catchJust p m h = liftWith $ \ ctx run -> Exc.catchJust p (run (m <$ ctx)) (run . (<$ ctx) . h)
-- | See @"Control.Exception".'Exc.handle'@.
--
-- @since 1.0.0.0
handle :: (Exc.Exception e, Has (Lift IO) sig m) => (e -> m a) -> m a -> m a
handle = flip catch
-- | See @"Control.Exception".'Exc.handleJust'@.
--
-- @since 1.0.0.0
handleJust
:: (Exc.Exception e, Has (Lift IO) sig m)
=> (e -> Maybe b)
-> (b -> m a)
-> m a
-> m a
handleJust p = flip (catchJust p)
-- | See @"Control.Exception".'Exc.try'@.
--
-- @since 1.0.0.0
try :: (Exc.Exception e, Has (Lift IO) sig m) => m a -> m (Either e a)
try m = (Right <$> m) `catch` (pure . Left)
-- | See @"Control.Exception".'Exc.tryJust'@.
--
-- @since 1.0.0.0
tryJust :: (Exc.Exception e, Has (Lift IO) sig m) => (e -> Maybe b) -> m a -> m (Either b a)
tryJust p m = catchJust p (Right <$> m) (pure . Left)
-- | See @"Control.Exception".'Exc.evaluate'@.
--
-- @since 1.0.0.0
evaluate :: Has (Lift IO) sig m => a -> m a
evaluate = sendM . Exc.evaluate
-- | See @"Control.Exception".'Exc.mask'@.
--
-- @since 1.0.0.0
mask :: Has (Lift IO) sig m => ((forall a . m a -> m a) -> m b) -> m b
mask with = liftWith $ \ ctx run -> Exc.mask $ \ restore ->
run (with (\ m -> liftWith $ \ ctx' run' -> restore (run' (m <$ ctx'))) <$ ctx)
-- | See @"Control.Exception".'Exc.mask_'@.
--
-- @since 1.0.0.0
mask_ :: Has (Lift IO) sig m => m a -> m a
mask_ m = mask $ const m
-- | See @"Control.Exception".'Exc.uninterruptibleMask'@.
--
-- @since 1.0.0.0
uninterruptibleMask :: Has (Lift IO) sig m => ((forall a . m a -> m a) -> m b) -> m b
uninterruptibleMask with = liftWith $ \ ctx run -> Exc.uninterruptibleMask $ \ restore ->
run (with (\ m -> liftWith $ \ ctx' run' -> restore (run' (m <$ ctx'))) <$ ctx)
-- | See @"Control.Exception".'Exc.uninterruptibleMask_'@.
--
-- @since 1.0.0.0
uninterruptibleMask_ :: Has (Lift IO) sig m => m a -> m a
uninterruptibleMask_ m = uninterruptibleMask $ const m
-- | See @"Control.Exception".'Exc.getMaskingState'@.
--
-- @since 1.0.0.0
getMaskingState :: Has (Lift IO) sig m => m Exc.MaskingState
getMaskingState = sendM Exc.getMaskingState
-- | See @"Control.Exception".'Exc.interruptible'@.
--
-- @since 1.0.0.0
interruptible :: Has (Lift IO) sig m => m a -> m a
interruptible m = liftWith $ \ ctx run -> Exc.interruptible (run (m <$ ctx))
-- | See @"Control.Exception".'Exc.allowInterrupt'@.
--
-- @since 1.0.0.0
allowInterrupt :: Has (Lift IO) sig m => m ()
allowInterrupt = sendM Exc.allowInterrupt
-- | See @"Control.Exception".'Exc.bracket'@.
--
-- @since 1.0.0.0
bracket
:: Has (Lift IO) sig m
=> m a
-> (a -> m b)
-> (a -> m c)
-> m c
bracket acquire release m = mask $ \ restore -> do
a <- acquire
r <- restore (m a) `onException` release a
r <$ release a
-- | See @"Control.Exception".'Exc.bracket_'@.
--
-- @since 1.0.0.0
bracket_
:: Has (Lift IO) sig m
=> m a
-> m b
-> m c
-> m c
bracket_ before after thing = bracket before (const after) (const thing)
-- | See @"Control.Exception".'Exc.bracketOnError'@.
--
-- @since 1.0.0.0
bracketOnError
:: Has (Lift IO) sig m
=> m a
-> (a -> m b)
-> (a -> m c)
-> m c
bracketOnError acquire release m = mask $ \ restore -> do
a <- acquire
restore (m a) `onException` release a
-- | See @"Control.Exception".'Exc.finally'@.
--
-- @since 1.0.0.0
finally
:: Has (Lift IO) sig m
=> m a
-> m b
-> m a
finally m sequel = mask $ \ restore -> (restore m `onException` sequel) <* sequel
-- | See @"Control.Exception".'Exc.onException'@.
--
-- @since 1.0.0.0
onException :: Has (Lift IO) sig m => m a -> m b -> m a
onException io what = io `catch` \e -> what >> throwIO (e :: Exc.SomeException)