unliftio-0.2.12.1: The MonadUnliftIO typeclass for unlifting monads to IO (batteries included)
Safe HaskellNone
LanguageHaskell2010

UnliftIO.Exception

Description

Unlifted Control.Exception, with extra async exception safety and more helper functions.

This module works best when your cleanup functions adhere to certain expectations around exception safety and interruptible actions. For more details, see this exception safety tutorial.

Synopsis

Throwing

throwIO :: (MonadIO m, Exception e) => e -> m a Source #

Synchronously throw the given exception.

Since: 0.1.0.0

throwString :: (MonadIO m, HasCallStack) => String -> m a Source #

A convenience function for throwing a user error. This is useful for cases where it would be too high a burden to define your own exception type.

This throws an exception of type StringException. When GHC supports it (base 4.9 and GHC 8.0 and onward), it includes a call stack.

Since: 0.1.0.0

data StringException Source #

Exception type thrown by throwString.

Note that the second field of the data constructor depends on GHC/base version. For base 4.9 and GHC 8.0 and later, the second field is a call stack. Previous versions of GHC and base do not support call stacks, and the field is simply unit (provided to make pattern matching across GHC versions easier).

Since: 0.1.0.0

Constructors

StringException String CallStack 

Instances

Instances details
Show StringException Source #

Since: 0.1.0.0

Instance details

Defined in UnliftIO.Exception

Methods

showsPrec :: Int -> StringException -> ShowS

show :: StringException -> String

showList :: [StringException] -> ShowS

Exception StringException Source #

Since: 0.1.0.0

Instance details

Defined in UnliftIO.Exception

stringException :: HasCallStack => String -> StringException Source #

Smart constructor for a StringException that deals with the call stack.

Since: 0.1.0.0

throwTo :: (Exception e, MonadIO m) => ThreadId -> e -> m () Source #

Throw an asynchronous exception to another thread.

Synchronously typed exceptions will be wrapped into an AsyncExceptionWrapper, see https://github.com/fpco/safe-exceptions#determining-sync-vs-async.

It's usually a better idea to use the UnliftIO.Async module, see https://github.com/fpco/safe-exceptions#quickstart.

Since: 0.1.0.0

impureThrow :: Exception e => e -> a Source #

Generate a pure value which, when forced, will synchronously throw the given exception.

Generally it's better to avoid using this function and instead use throwIO, see https://github.com/fpco/safe-exceptions#quickstart.

Since: 0.1.0.0

fromEither :: (Exception e, MonadIO m) => Either e a -> m a Source #

Unwrap an Either value, throwing its Left value as a runtime exception via throwIO if present.

Since: 0.1.0.0

fromEitherIO :: (Exception e, MonadIO m) => IO (Either e a) -> m a Source #

Same as fromEither, but works on an IO-wrapped Either.

Since: 0.1.0.0

fromEitherM :: (Exception e, MonadIO m) => m (Either e a) -> m a Source #

Same as fromEither, but works on an m-wrapped Either.

Since: 0.1.0.0

Catching (with recovery)

catch :: (MonadUnliftIO m, Exception e) => m a -> (e -> m a) -> m a Source #

Unlifted catch, but will not catch asynchronous exceptions.

Since: 0.1.0.0

catchIO :: MonadUnliftIO m => m a -> (IOException -> m a) -> m a Source #

catch specialized to only catching IOExceptions.

Since: 0.1.0.0

catchAny :: MonadUnliftIO m => m a -> (SomeException -> m a) -> m a Source #

catch specialized to catch all synchronous exception.

Since: 0.1.0.0

catchDeep :: (MonadUnliftIO m, Exception e, NFData a) => m a -> (e -> m a) -> m a Source #

Same as catch, but fully force evaluation of the result value to find all impure exceptions.

Since: 0.1.0.0

catchAnyDeep :: (NFData a, MonadUnliftIO m) => m a -> (SomeException -> m a) -> m a Source #

catchDeep specialized to catch all synchronous exception.

Since: 0.1.0.0

catchJust :: (MonadUnliftIO m, Exception e) => (e -> Maybe b) -> m a -> (b -> m a) -> m a Source #

catchJust is like catch but it takes an extra argument which is an exception predicate, a function which selects which type of exceptions we're interested in.

Since: 0.1.0.0

handle :: (MonadUnliftIO m, Exception e) => (e -> m a) -> m a -> m a Source #

Flipped version of catch.

Since: 0.1.0.0

handleIO :: MonadUnliftIO m => (IOException -> m a) -> m a -> m a Source #

handle specialized to only catching IOExceptions.

Since: 0.1.0.0

handleAny :: MonadUnliftIO m => (SomeException -> m a) -> m a -> m a Source #

Flipped version of catchAny.

Since: 0.1.0.0

handleDeep :: (MonadUnliftIO m, Exception e, NFData a) => (e -> m a) -> m a -> m a Source #

Flipped version of catchDeep.

Since: 0.1.0.0

handleAnyDeep :: (MonadUnliftIO m, NFData a) => (SomeException -> m a) -> m a -> m a Source #

Flipped version of catchAnyDeep.

Since: 0.1.0.0

handleJust :: (MonadUnliftIO m, Exception e) => (e -> Maybe b) -> (b -> m a) -> m a -> m a Source #

Flipped catchJust.

Since: 0.1.0.0

try :: (MonadUnliftIO m, Exception e) => m a -> m (Either e a) Source #

Unlifted try, but will not catch asynchronous exceptions.

Since: 0.1.0.0

tryIO :: MonadUnliftIO m => m a -> m (Either IOException a) Source #

try specialized to only catching IOExceptions.

Since: 0.1.0.0

tryAny :: MonadUnliftIO m => m a -> m (Either SomeException a) Source #

try specialized to catch all synchronous exceptions.

Since: 0.1.0.0

tryDeep :: (MonadUnliftIO m, Exception e, NFData a) => m a -> m (Either e a) Source #

Same as try, but fully force evaluation of the result value to find all impure exceptions.

Since: 0.1.0.0

tryAnyDeep :: (MonadUnliftIO m, NFData a) => m a -> m (Either SomeException a) Source #

tryDeep specialized to catch all synchronous exceptions.

Since: 0.1.0.0

tryJust :: (MonadUnliftIO m, Exception e) => (e -> Maybe b) -> m a -> m (Either b a) Source #

A variant of try that takes an exception predicate to select which exceptions are caught.

Since: 0.1.0.0

pureTry :: a -> Either SomeException a Source #

Evaluate the value to WHNF and catch any synchronous exceptions.

The expression may still have bottom values within it; you may instead want to use pureTryDeep.

Since: 0.2.2.0

pureTryDeep :: NFData a => a -> Either SomeException a Source #

Evaluate the value to NF and catch any synchronous exceptions.

Since: 0.2.2.0

data Handler m a Source #

Generalized version of Handler.

Since: 0.1.0.0

Constructors

forall e.Exception e => Handler (e -> m a) 

catches :: MonadUnliftIO m => m a -> [Handler m a] -> m a Source #

Same as upstream catches, but will not catch asynchronous exceptions.

Since: 0.1.0.0

catchesDeep :: (MonadUnliftIO m, NFData a) => m a -> [Handler m a] -> m a Source #

Same as catches, but fully force evaluation of the result value to find all impure exceptions.

Since: 0.1.0.0

Cleanup (no recovery)

onException :: MonadUnliftIO m => m a -> m b -> m a Source #

Async safe version of onException.

Since: 0.1.0.0

bracket :: MonadUnliftIO m => m a -> (a -> m b) -> (a -> m c) -> m c Source #

Async safe version of bracket.

Since: 0.1.0.0

bracket_ :: MonadUnliftIO m => m a -> m b -> m c -> m c Source #

Async safe version of bracket_.

Since: 0.1.0.0

finally :: MonadUnliftIO m => m a -> m b -> m a Source #

Async safe version of finally.

Since: 0.1.0.0

withException :: (MonadUnliftIO m, Exception e) => m a -> (e -> m b) -> m a Source #

Like onException, but provides the handler the thrown exception.

Since: 0.1.0.0

bracketOnError :: MonadUnliftIO m => m a -> (a -> m b) -> (a -> m c) -> m c Source #

Async safe version of bracketOnError.

Since: 0.1.0.0

bracketOnError_ :: MonadUnliftIO m => m a -> m b -> m c -> m c Source #

A variant of bracketOnError where the return value from the first computation is not required.

Since: 0.1.0.0

Coercion to sync and async

data SyncExceptionWrapper Source #

Wrap up an asynchronous exception to be treated as a synchronous exception.

This is intended to be created via toSyncException.

Since: 0.1.0.0

Constructors

forall e.Exception e => SyncExceptionWrapper e 

Instances

Instances details
Show SyncExceptionWrapper Source #

Since: 0.1.0.0

Instance details

Defined in UnliftIO.Exception

Methods

showsPrec :: Int -> SyncExceptionWrapper -> ShowS

show :: SyncExceptionWrapper -> String

showList :: [SyncExceptionWrapper] -> ShowS

Exception SyncExceptionWrapper Source #

Since: 0.1.0.0

Instance details

Defined in UnliftIO.Exception

toSyncException :: Exception e => e -> SomeException Source #

Convert an exception into a synchronous exception.

For synchronous exceptions, this is the same as toException. For asynchronous exceptions, this will wrap up the exception with SyncExceptionWrapper.

Since: 0.1.0.0

data AsyncExceptionWrapper Source #

Wrap up a synchronous exception to be treated as an asynchronous exception.

This is intended to be created via toAsyncException.

Since: 0.1.0.0

Constructors

forall e.Exception e => AsyncExceptionWrapper e 

Instances

Instances details
Show AsyncExceptionWrapper Source #

Since: 0.1.0.0

Instance details

Defined in UnliftIO.Exception

Methods

showsPrec :: Int -> AsyncExceptionWrapper -> ShowS

show :: AsyncExceptionWrapper -> String

showList :: [AsyncExceptionWrapper] -> ShowS

Exception AsyncExceptionWrapper Source #

Since: 0.1.0.0

Instance details

Defined in UnliftIO.Exception

toAsyncException :: Exception e => e -> SomeException Source #

Convert an exception into an asynchronous exception.

For asynchronous exceptions, this is the same as toException. For synchronous exceptions, this will wrap up the exception with AsyncExceptionWrapper.

Since: 0.1.0.0

Check exception type

isSyncException :: Exception e => e -> Bool Source #

Check if the given exception is synchronous.

Since: 0.1.0.0

isAsyncException :: Exception e => e -> Bool Source #

Check if the given exception is asynchronous.

Since: 0.1.0.0

Masking

mask :: MonadUnliftIO m => ((forall a. m a -> m a) -> m b) -> m b Source #

Unlifted version of mask.

Since: 0.1.0.0

uninterruptibleMask :: MonadUnliftIO m => ((forall a. m a -> m a) -> m b) -> m b Source #

Unlifted version of uninterruptibleMask.

Since: 0.1.0.0

mask_ :: MonadUnliftIO m => m a -> m a Source #

Unlifted version of mask_.

Since: 0.1.0.0

uninterruptibleMask_ :: MonadUnliftIO m => m a -> m a Source #

Unlifted version of uninterruptibleMask_.

Since: 0.1.0.0

Evaluation

evaluate :: MonadIO m => a -> m a Source #

Lifted version of evaluate.

Since: 0.1.0.0

evaluateDeep :: (MonadIO m, NFData a) => a -> m a Source #

Deeply evaluate a value using evaluate and NFData.

Since: 0.1.0.0

Reexports

class (Typeable e, Show e) => Exception e where #

Minimal complete definition

Nothing

Methods

toException :: e -> SomeException #

fromException :: SomeException -> Maybe e #

displayException :: e -> String #

Instances

Instances details
Exception AsyncCancelled 
Instance details

Defined in Control.Concurrent.Async

Exception ExceptionInLinkedThread 
Instance details

Defined in Control.Concurrent.Async

Exception NestedAtomically 
Instance details

Defined in Control.Exception.Base

Methods

toException :: NestedAtomically -> SomeException #

fromException :: SomeException -> Maybe NestedAtomically #

displayException :: NestedAtomically -> String #

Exception NoMethodError 
Instance details

Defined in Control.Exception.Base

Methods

toException :: NoMethodError -> SomeException #

fromException :: SomeException -> Maybe NoMethodError #

displayException :: NoMethodError -> String #

Exception NonTermination 
Instance details

Defined in Control.Exception.Base

Methods

toException :: NonTermination -> SomeException #

fromException :: SomeException -> Maybe NonTermination #

displayException :: NonTermination -> String #

Exception PatternMatchFail 
Instance details

Defined in Control.Exception.Base

Methods

toException :: PatternMatchFail -> SomeException #

fromException :: SomeException -> Maybe PatternMatchFail #

displayException :: PatternMatchFail -> String #

Exception RecConError 
Instance details

Defined in Control.Exception.Base

Methods

toException :: RecConError -> SomeException #

fromException :: SomeException -> Maybe RecConError #

displayException :: RecConError -> String #

Exception RecSelError 
Instance details

Defined in Control.Exception.Base

Methods

toException :: RecSelError -> SomeException #

fromException :: SomeException -> Maybe RecSelError #

displayException :: RecSelError -> String #

Exception RecUpdError 
Instance details

Defined in Control.Exception.Base

Methods

toException :: RecUpdError -> SomeException #

fromException :: SomeException -> Maybe RecUpdError #

displayException :: RecUpdError -> String #

Exception TypeError 
Instance details

Defined in Control.Exception.Base

Methods

toException :: TypeError -> SomeException #

fromException :: SomeException -> Maybe TypeError #

displayException :: TypeError -> String #

Exception ErrorCall 
Instance details

Defined in GHC.Exception

Methods

toException :: ErrorCall -> SomeException #

fromException :: SomeException -> Maybe ErrorCall #

displayException :: ErrorCall -> String #

Exception ArithException 
Instance details

Defined in GHC.Exception.Type

Methods

toException :: ArithException -> SomeException #

fromException :: SomeException -> Maybe ArithException #

displayException :: ArithException -> String #

Exception SomeException 
Instance details

Defined in GHC.Exception.Type

Exception AllocationLimitExceeded 
Instance details

Defined in GHC.IO.Exception

Methods

toException :: AllocationLimitExceeded -> SomeException #

fromException :: SomeException -> Maybe AllocationLimitExceeded #

displayException :: AllocationLimitExceeded -> String #

Exception ArrayException 
Instance details

Defined in GHC.IO.Exception

Methods

toException :: ArrayException -> SomeException #

fromException :: SomeException -> Maybe ArrayException #

displayException :: ArrayException -> String #

Exception AssertionFailed 
Instance details

Defined in GHC.IO.Exception

Methods

toException :: AssertionFailed -> SomeException #

fromException :: SomeException -> Maybe AssertionFailed #

displayException :: AssertionFailed -> String #

Exception AsyncException 
Instance details

Defined in GHC.IO.Exception

Methods

toException :: AsyncException -> SomeException #

fromException :: SomeException -> Maybe AsyncException #

displayException :: AsyncException -> String #

Exception BlockedIndefinitelyOnMVar 
Instance details

Defined in GHC.IO.Exception

Methods

toException :: BlockedIndefinitelyOnMVar -> SomeException #

fromException :: SomeException -> Maybe BlockedIndefinitelyOnMVar #

displayException :: BlockedIndefinitelyOnMVar -> String #

Exception BlockedIndefinitelyOnSTM 
Instance details

Defined in GHC.IO.Exception

Methods

toException :: BlockedIndefinitelyOnSTM -> SomeException #

fromException :: SomeException -> Maybe BlockedIndefinitelyOnSTM #

displayException :: BlockedIndefinitelyOnSTM -> String #

Exception CompactionFailed 
Instance details

Defined in GHC.IO.Exception

Methods

toException :: CompactionFailed -> SomeException #

fromException :: SomeException -> Maybe CompactionFailed #

displayException :: CompactionFailed -> String #

Exception Deadlock 
Instance details

Defined in GHC.IO.Exception

Methods

toException :: Deadlock -> SomeException #

fromException :: SomeException -> Maybe Deadlock #

displayException :: Deadlock -> String #

Exception IOException 
Instance details

Defined in GHC.IO.Exception

Exception SomeAsyncException 
Instance details

Defined in GHC.IO.Exception

Exception ExitCode 
Instance details

Defined in GHC.IO.Exception

Methods

toException :: ExitCode -> SomeException #

fromException :: SomeException -> Maybe ExitCode #

displayException :: ExitCode -> String #

Exception FixIOException 
Instance details

Defined in GHC.IO.Exception

Methods

toException :: FixIOException -> SomeException #

fromException :: SomeException -> Maybe FixIOException #

displayException :: FixIOException -> String #

Exception Void 
Instance details

Defined in Data.Void

Methods

toException :: Void -> SomeException #

fromException :: SomeException -> Maybe Void #

displayException :: Void -> String #

Exception StringException Source #

Since: 0.1.0.0

Instance details

Defined in UnliftIO.Exception

Exception AsyncExceptionWrapper Source #

Since: 0.1.0.0

Instance details

Defined in UnliftIO.Exception

Exception SyncExceptionWrapper Source #

Since: 0.1.0.0

Instance details

Defined in UnliftIO.Exception

Exception ConcException Source # 
Instance details

Defined in UnliftIO.Internals.Async

Exception Timeout 
Instance details

Defined in System.Timeout

Methods

toException :: Timeout -> SomeException #

fromException :: SomeException -> Maybe Timeout #

displayException :: Timeout -> String #

class Typeable (a :: k) #

Minimal complete definition

typeRep#

data SomeException #

Constructors

Exception e => SomeException e 

Instances

Instances details
Show SomeException 
Instance details

Defined in GHC.Exception.Type

Methods

showsPrec :: Int -> SomeException -> ShowS

show :: SomeException -> String

showList :: [SomeException] -> ShowS

Exception SomeException 
Instance details

Defined in GHC.Exception.Type

data SomeAsyncException #

Constructors

Exception e => SomeAsyncException e 

Instances

Instances details
Show SomeAsyncException 
Instance details

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> SomeAsyncException -> ShowS

show :: SomeAsyncException -> String

showList :: [SomeAsyncException] -> ShowS

Exception SomeAsyncException 
Instance details

Defined in GHC.IO.Exception

data IOException #

Instances

Instances details
Eq IOException 
Instance details

Defined in GHC.IO.Exception

Methods

(==) :: IOException -> IOException -> Bool

(/=) :: IOException -> IOException -> Bool

Show IOException 
Instance details

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> IOException -> ShowS

show :: IOException -> String

showList :: [IOException] -> ShowS

Exception IOException 
Instance details

Defined in GHC.IO.Exception

assert :: Bool -> a -> a #