Safe Haskell	Safe-Inferred
Language	Haskell2010

Control.Exception.Extra

Contents

Exception catching/ignoring

Description

Extra functions for Control.Exception. These functions provide retrying, showing in the presence of exceptions, and functions to catch/ignore exceptions, including monomorphic (no Exception context) versions.

If you want to use a safer set of exceptions see the safe-exceptions package.

Synopsis

assert :: Bool -> a -> a
throwTo :: Exception e => ThreadId -> e -> IO ()
allowInterrupt :: IO ()
catches :: IO a -> [Handler a] -> IO a
bracket :: IO a -> (a -> IO b) -> (a -> IO c) -> IO c
bracketOnError :: IO a -> (a -> IO b) -> (a -> IO c) -> IO c
bracket_ :: IO a -> IO b -> IO c -> IO c
catchJust :: Exception e => (e -> Maybe b) -> IO a -> (b -> IO a) -> IO a
finally :: IO a -> IO b -> IO a
handle :: Exception e => (e -> IO a) -> IO a -> IO a
handleJust :: Exception e => (e -> Maybe b) -> (b -> IO a) -> IO a -> IO a
mapException :: (Exception e1, Exception e2) => (e1 -> e2) -> a -> a
onException :: IO a -> IO b -> IO a
try :: Exception e => IO a -> IO (Either e a)
tryJust :: Exception e => (e -> Maybe b) -> IO a -> IO (Either b a)
tryWithContext :: Exception e => IO a -> IO (Either (ExceptionWithContext e) a)
throw :: forall a e. (HasCallStack, Exception e) => e -> a
addExceptionContext :: ExceptionAnnotation a => a -> SomeException -> SomeException
someExceptionContext :: SomeException -> ExceptionContext
annotateIO :: ExceptionAnnotation e => e -> IO a -> IO a
catch :: Exception e => IO a -> (e -> IO a) -> IO a
catchNoPropagate :: Exception e => IO a -> (ExceptionWithContext e -> IO a) -> IO a
evaluate :: a -> IO a
getMaskingState :: IO MaskingState
interruptible :: IO a -> IO a
mask :: ((forall a. IO a -> IO a) -> IO b) -> IO b
mask_ :: IO a -> IO a
rethrowIO :: Exception e => ExceptionWithContext e -> IO a
throwIO :: (HasCallStack, Exception e) => e -> IO a
uninterruptibleMask :: ((forall a. IO a -> IO a) -> IO b) -> IO b
uninterruptibleMask_ :: IO a -> IO a
asyncExceptionFromException :: Exception e => SomeException -> Maybe e
asyncExceptionToException :: Exception e => e -> SomeException
ioError :: HasCallStack => IOError -> IO a
data Handler a = Exception e => Handler (e -> IO a)
data NestedAtomically = NestedAtomically
newtype NoMethodError = NoMethodError String
data NonTermination = NonTermination
newtype PatternMatchFail = PatternMatchFail String
newtype RecConError = RecConError String
newtype RecSelError = RecSelError String
newtype RecUpdError = RecUpdError String
newtype TypeError = TypeError String
data ErrorCall where
- ErrorCall String
- pattern ErrorCallWithLocation :: String -> String -> ErrorCall
data ArithException
- = Overflow
- | Underflow
- | LossOfPrecision
- | DivideByZero
- | Denormal
- | RatioZeroDenominator
class (Typeable e, Show e) => Exception e where
- toException :: e -> SomeException
- fromException :: SomeException -> Maybe e
- displayException :: e -> String
- backtraceDesired :: e -> Bool
data ExceptionWithContext a = ExceptionWithContext ExceptionContext a
newtype NoBacktrace e = NoBacktrace e
data SomeException = (Exception e, HasExceptionContext) => SomeException e
data WhileHandling = WhileHandling SomeException
data MaskingState
- = Unmasked
- | MaskedInterruptible
- | MaskedUninterruptible
data AllocationLimitExceeded = AllocationLimitExceeded
data ArrayException
- = IndexOutOfBounds String
- | UndefinedElement String
newtype AssertionFailed = AssertionFailed String
data AsyncException
- = StackOverflow
- | HeapOverflow
- | ThreadKilled
- | UserInterrupt
data BlockedIndefinitelyOnMVar = BlockedIndefinitelyOnMVar
data BlockedIndefinitelyOnSTM = BlockedIndefinitelyOnSTM
newtype CompactionFailed = CompactionFailed String
data Deadlock = Deadlock
data IOException
data SomeAsyncException = Exception e => SomeAsyncException e
type Partial = HasCallStack
retry :: Int -> IO a -> IO a
retryBool :: Exception e => (e -> Bool) -> Int -> IO a -> IO a
errorWithoutStackTrace :: [Char] -> a
showException :: Show e => e -> IO String
stringException :: String -> IO String
errorIO :: Partial => String -> IO a
assertIO :: Partial => Bool -> IO ()
ignore :: IO () -> IO ()
catch_ :: IO a -> (SomeException -> IO a) -> IO a
handle_ :: (SomeException -> IO a) -> IO a -> IO a
try_ :: IO a -> IO (Either SomeException a)
catchJust_ :: (SomeException -> Maybe b) -> IO a -> (b -> IO a) -> IO a
handleJust_ :: (SomeException -> Maybe b) -> (b -> IO a) -> IO a -> IO a
tryJust_ :: (SomeException -> Maybe b) -> IO a -> IO (Either b a)
catchBool :: Exception e => (e -> Bool) -> IO a -> (e -> IO a) -> IO a
handleBool :: Exception e => (e -> Bool) -> (e -> IO a) -> IO a -> IO a
tryBool :: Exception e => (e -> Bool) -> IO a -> IO (Either e a)

Documentation

assert :: Bool -> a -> a #

throwTo :: Exception e => ThreadId -> e -> IO () #

allowInterrupt :: IO () #

catches :: IO a -> [Handler a] -> IO a #

bracket :: IO a -> (a -> IO b) -> (a -> IO c) -> IO c #

bracketOnError :: IO a -> (a -> IO b) -> (a -> IO c) -> IO c #

bracket_ :: IO a -> IO b -> IO c -> IO c #

catchJust :: Exception e => (e -> Maybe b) -> IO a -> (b -> IO a) -> IO a #

finally :: IO a -> IO b -> IO a #

handle :: Exception e => (e -> IO a) -> IO a -> IO a #

handleJust :: Exception e => (e -> Maybe b) -> (b -> IO a) -> IO a -> IO a #

mapException :: (Exception e1, Exception e2) => (e1 -> e2) -> a -> a #

onException :: IO a -> IO b -> IO a #

try :: Exception e => IO a -> IO (Either e a) #

tryJust :: Exception e => (e -> Maybe b) -> IO a -> IO (Either b a) #

tryWithContext :: Exception e => IO a -> IO (Either (ExceptionWithContext e) a) #

throw :: forall a e. (HasCallStack, Exception e) => e -> a #

addExceptionContext :: ExceptionAnnotation a => a -> SomeException -> SomeException #

someExceptionContext :: SomeException -> ExceptionContext #

annotateIO :: ExceptionAnnotation e => e -> IO a -> IO a #

catch :: Exception e => IO a -> (e -> IO a) -> IO a #

catchNoPropagate :: Exception e => IO a -> (ExceptionWithContext e -> IO a) -> IO a #

evaluate :: a -> IO a #

getMaskingState :: IO MaskingState #

interruptible :: IO a -> IO a #

mask :: ((forall a. IO a -> IO a) -> IO b) -> IO b #

mask_ :: IO a -> IO a #

rethrowIO :: Exception e => ExceptionWithContext e -> IO a #

throwIO :: (HasCallStack, Exception e) => e -> IO a #

uninterruptibleMask :: ((forall a. IO a -> IO a) -> IO b) -> IO b #

uninterruptibleMask_ :: IO a -> IO a #

asyncExceptionFromException :: Exception e => SomeException -> Maybe e #

asyncExceptionToException :: Exception e => e -> SomeException #

ioError :: HasCallStack => IOError -> IO a #

data Handler a #

Constructors

Exception e => Handler (e -> IO a)

Instances

Instances details

Functor Handler #
Instance details Defined in GHC.Internal.Control.Exception Methods fmap :: (a -> b) -> Handler a -> Handler b # (<$) :: a -> Handler b -> Handler a #

data NestedAtomically #

Constructors

NestedAtomically

Instances

Instances details

Exception NestedAtomically #
Instance details Defined in GHC.Internal.Control.Exception.Base Methods toException :: NestedAtomically -> SomeException # fromException :: SomeException -> Maybe NestedAtomically # displayException :: NestedAtomically -> String # backtraceDesired :: NestedAtomically -> Bool #
Show NestedAtomically #
Instance details Defined in GHC.Internal.Control.Exception.Base Methods showsPrec :: Int -> NestedAtomically -> ShowS show :: NestedAtomically -> String showList :: [NestedAtomically] -> ShowS

newtype NoMethodError #

Constructors

NoMethodError String

Instances

Instances details

Exception NoMethodError #
Instance details Defined in GHC.Internal.Control.Exception.Base Methods toException :: NoMethodError -> SomeException # fromException :: SomeException -> Maybe NoMethodError # displayException :: NoMethodError -> String # backtraceDesired :: NoMethodError -> Bool #
Show NoMethodError #
Instance details Defined in GHC.Internal.Control.Exception.Base Methods showsPrec :: Int -> NoMethodError -> ShowS show :: NoMethodError -> String showList :: [NoMethodError] -> ShowS

data NonTermination #

Constructors

NonTermination

Instances

Instances details

Exception NonTermination #
Instance details Defined in GHC.Internal.Control.Exception.Base Methods toException :: NonTermination -> SomeException # fromException :: SomeException -> Maybe NonTermination # displayException :: NonTermination -> String # backtraceDesired :: NonTermination -> Bool #
Show NonTermination #
Instance details Defined in GHC.Internal.Control.Exception.Base Methods showsPrec :: Int -> NonTermination -> ShowS show :: NonTermination -> String showList :: [NonTermination] -> ShowS

newtype PatternMatchFail #

Constructors

PatternMatchFail String

Instances

Instances details

Exception PatternMatchFail #
Instance details Defined in GHC.Internal.Control.Exception.Base Methods toException :: PatternMatchFail -> SomeException # fromException :: SomeException -> Maybe PatternMatchFail # displayException :: PatternMatchFail -> String # backtraceDesired :: PatternMatchFail -> Bool #
Show PatternMatchFail #
Instance details Defined in GHC.Internal.Control.Exception.Base Methods showsPrec :: Int -> PatternMatchFail -> ShowS show :: PatternMatchFail -> String showList :: [PatternMatchFail] -> ShowS

newtype RecConError #

Constructors

RecConError String

Instances

Instances details

Exception RecConError #
Instance details Defined in GHC.Internal.Control.Exception.Base Methods toException :: RecConError -> SomeException # fromException :: SomeException -> Maybe RecConError # displayException :: RecConError -> String # backtraceDesired :: RecConError -> Bool #
Show RecConError #
Instance details Defined in GHC.Internal.Control.Exception.Base Methods showsPrec :: Int -> RecConError -> ShowS show :: RecConError -> String showList :: [RecConError] -> ShowS

newtype RecSelError #

Constructors

RecSelError String

Instances

Instances details

Exception RecSelError #
Instance details Defined in GHC.Internal.Control.Exception.Base Methods toException :: RecSelError -> SomeException # fromException :: SomeException -> Maybe RecSelError # displayException :: RecSelError -> String # backtraceDesired :: RecSelError -> Bool #
Show RecSelError #
Instance details Defined in GHC.Internal.Control.Exception.Base Methods showsPrec :: Int -> RecSelError -> ShowS show :: RecSelError -> String showList :: [RecSelError] -> ShowS

newtype RecUpdError #

Constructors

RecUpdError String

Instances

Instances details

Exception RecUpdError #
Instance details Defined in GHC.Internal.Control.Exception.Base Methods toException :: RecUpdError -> SomeException # fromException :: SomeException -> Maybe RecUpdError # displayException :: RecUpdError -> String # backtraceDesired :: RecUpdError -> Bool #
Show RecUpdError #
Instance details Defined in GHC.Internal.Control.Exception.Base Methods showsPrec :: Int -> RecUpdError -> ShowS show :: RecUpdError -> String showList :: [RecUpdError] -> ShowS

newtype TypeError #

Constructors

TypeError String

Instances

Instances details

Exception TypeError #
Instance details Defined in GHC.Internal.Control.Exception.Base Methods toException :: TypeError -> SomeException # fromException :: SomeException -> Maybe TypeError # displayException :: TypeError -> String # backtraceDesired :: TypeError -> Bool #
Show TypeError #
Instance details Defined in GHC.Internal.Control.Exception.Base Methods showsPrec :: Int -> TypeError -> ShowS show :: TypeError -> String showList :: [TypeError] -> ShowS

data ErrorCall #

Constructors

ErrorCall String

Bundled Patterns

pattern ErrorCallWithLocation :: String -> String -> ErrorCall

Instances

Instances details

Exception ErrorCall #
Instance details Defined in GHC.Internal.Exception Methods toException :: ErrorCall -> SomeException # fromException :: SomeException -> Maybe ErrorCall # displayException :: ErrorCall -> String # backtraceDesired :: ErrorCall -> Bool #
Show ErrorCall #
Instance details Defined in GHC.Internal.Exception Methods showsPrec :: Int -> ErrorCall -> ShowS show :: ErrorCall -> String showList :: [ErrorCall] -> ShowS
Eq ErrorCall #
Instance details Defined in GHC.Internal.Exception Methods (==) :: ErrorCall -> ErrorCall -> Bool (/=) :: ErrorCall -> ErrorCall -> Bool
Ord ErrorCall #
Instance details Defined in GHC.Internal.Exception Methods compare :: ErrorCall -> ErrorCall -> Ordering (<) :: ErrorCall -> ErrorCall -> Bool (<=) :: ErrorCall -> ErrorCall -> Bool (>) :: ErrorCall -> ErrorCall -> Bool (>=) :: ErrorCall -> ErrorCall -> Bool max :: ErrorCall -> ErrorCall -> ErrorCall min :: ErrorCall -> ErrorCall -> ErrorCall

data ArithException #

Constructors

Overflow
Underflow
LossOfPrecision
DivideByZero
Denormal
RatioZeroDenominator

Instances

Instances details

Exception ArithException #
Instance details Defined in GHC.Internal.Exception.Type Methods toException :: ArithException -> SomeException # fromException :: SomeException -> Maybe ArithException # displayException :: ArithException -> String # backtraceDesired :: ArithException -> Bool #
Show ArithException #
Instance details Defined in GHC.Internal.Exception.Type Methods showsPrec :: Int -> ArithException -> ShowS show :: ArithException -> String showList :: [ArithException] -> ShowS
Eq ArithException #
Instance details Defined in GHC.Internal.Exception.Type Methods (==) :: ArithException -> ArithException -> Bool (/=) :: ArithException -> ArithException -> Bool
Ord ArithException #
Instance details Defined in GHC.Internal.Exception.Type Methods compare :: ArithException -> ArithException -> Ordering (<) :: ArithException -> ArithException -> Bool (<=) :: ArithException -> ArithException -> Bool (>) :: ArithException -> ArithException -> Bool (>=) :: ArithException -> ArithException -> Bool max :: ArithException -> ArithException -> ArithException min :: ArithException -> ArithException -> ArithException

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

Minimal complete definition

Nothing

Methods

toException :: e -> SomeException #

fromException :: SomeException -> Maybe e #

displayException :: e -> String #

backtraceDesired :: e -> Bool #

Instances

Instances details

Exception Timeout #
Instance details Defined in System.Timeout Methods toException :: Timeout -> SomeException # fromException :: SomeException -> Maybe Timeout # displayException :: Timeout -> String # backtraceDesired :: Timeout -> Bool #
Exception SizeOverflowException #
Instance details Defined in Data.ByteString.Internal.Type Methods toException :: SizeOverflowException -> SomeException # fromException :: SomeException -> Maybe SizeOverflowException # displayException :: SizeOverflowException -> String # backtraceDesired :: SizeOverflowException -> Bool #
Exception Void #
Instance details Defined in GHC.Internal.Exception.Type Methods toException :: Void -> SomeException # fromException :: SomeException -> Maybe Void # displayException :: Void -> String # backtraceDesired :: Void -> Bool #
Exception NestedAtomically #
Instance details Defined in GHC.Internal.Control.Exception.Base Methods toException :: NestedAtomically -> SomeException # fromException :: SomeException -> Maybe NestedAtomically # displayException :: NestedAtomically -> String # backtraceDesired :: NestedAtomically -> Bool #
Exception NoMatchingContinuationPrompt #
Instance details Defined in GHC.Internal.Control.Exception.Base Methods toException :: NoMatchingContinuationPrompt -> SomeException # fromException :: SomeException -> Maybe NoMatchingContinuationPrompt # displayException :: NoMatchingContinuationPrompt -> String # backtraceDesired :: NoMatchingContinuationPrompt -> Bool #
Exception NoMethodError #
Instance details Defined in GHC.Internal.Control.Exception.Base Methods toException :: NoMethodError -> SomeException # fromException :: SomeException -> Maybe NoMethodError # displayException :: NoMethodError -> String # backtraceDesired :: NoMethodError -> Bool #
Exception NonTermination #
Instance details Defined in GHC.Internal.Control.Exception.Base Methods toException :: NonTermination -> SomeException # fromException :: SomeException -> Maybe NonTermination # displayException :: NonTermination -> String # backtraceDesired :: NonTermination -> Bool #
Exception PatternMatchFail #
Instance details Defined in GHC.Internal.Control.Exception.Base Methods toException :: PatternMatchFail -> SomeException # fromException :: SomeException -> Maybe PatternMatchFail # displayException :: PatternMatchFail -> String # backtraceDesired :: PatternMatchFail -> Bool #
Exception RecConError #
Instance details Defined in GHC.Internal.Control.Exception.Base Methods toException :: RecConError -> SomeException # fromException :: SomeException -> Maybe RecConError # displayException :: RecConError -> String # backtraceDesired :: RecConError -> Bool #
Exception RecSelError #
Instance details Defined in GHC.Internal.Control.Exception.Base Methods toException :: RecSelError -> SomeException # fromException :: SomeException -> Maybe RecSelError # displayException :: RecSelError -> String # backtraceDesired :: RecSelError -> Bool #
Exception RecUpdError #
Instance details Defined in GHC.Internal.Control.Exception.Base Methods toException :: RecUpdError -> SomeException # fromException :: SomeException -> Maybe RecUpdError # displayException :: RecUpdError -> String # backtraceDesired :: RecUpdError -> Bool #
Exception TypeError #
Instance details Defined in GHC.Internal.Control.Exception.Base Methods toException :: TypeError -> SomeException # fromException :: SomeException -> Maybe TypeError # displayException :: TypeError -> String # backtraceDesired :: TypeError -> Bool #
Exception ErrorCall #
Instance details Defined in GHC.Internal.Exception Methods toException :: ErrorCall -> SomeException # fromException :: SomeException -> Maybe ErrorCall # displayException :: ErrorCall -> String # backtraceDesired :: ErrorCall -> Bool #
Exception ArithException #
Instance details Defined in GHC.Internal.Exception.Type Methods toException :: ArithException -> SomeException # fromException :: SomeException -> Maybe ArithException # displayException :: ArithException -> String # backtraceDesired :: ArithException -> Bool #
Exception SomeException #
Instance details Defined in GHC.Internal.Exception.Type Methods toException :: SomeException -> SomeException # fromException :: SomeException -> Maybe SomeException # displayException :: SomeException -> String # backtraceDesired :: SomeException -> Bool #
Exception AllocationLimitExceeded #
Instance details Defined in GHC.Internal.IO.Exception Methods toException :: AllocationLimitExceeded -> SomeException # fromException :: SomeException -> Maybe AllocationLimitExceeded # displayException :: AllocationLimitExceeded -> String # backtraceDesired :: AllocationLimitExceeded -> Bool #
Exception ArrayException #
Instance details Defined in GHC.Internal.IO.Exception Methods toException :: ArrayException -> SomeException # fromException :: SomeException -> Maybe ArrayException # displayException :: ArrayException -> String # backtraceDesired :: ArrayException -> Bool #
Exception AssertionFailed #
Instance details Defined in GHC.Internal.IO.Exception Methods toException :: AssertionFailed -> SomeException # fromException :: SomeException -> Maybe AssertionFailed # displayException :: AssertionFailed -> String # backtraceDesired :: AssertionFailed -> Bool #
Exception AsyncException #
Instance details Defined in GHC.Internal.IO.Exception Methods toException :: AsyncException -> SomeException # fromException :: SomeException -> Maybe AsyncException # displayException :: AsyncException -> String # backtraceDesired :: AsyncException -> Bool #
Exception BlockedIndefinitelyOnMVar #
Instance details Defined in GHC.Internal.IO.Exception Methods toException :: BlockedIndefinitelyOnMVar -> SomeException # fromException :: SomeException -> Maybe BlockedIndefinitelyOnMVar # displayException :: BlockedIndefinitelyOnMVar -> String # backtraceDesired :: BlockedIndefinitelyOnMVar -> Bool #
Exception BlockedIndefinitelyOnSTM #
Instance details Defined in GHC.Internal.IO.Exception Methods toException :: BlockedIndefinitelyOnSTM -> SomeException # fromException :: SomeException -> Maybe BlockedIndefinitelyOnSTM # displayException :: BlockedIndefinitelyOnSTM -> String # backtraceDesired :: BlockedIndefinitelyOnSTM -> Bool #
Exception CompactionFailed #
Instance details Defined in GHC.Internal.IO.Exception Methods toException :: CompactionFailed -> SomeException # fromException :: SomeException -> Maybe CompactionFailed # displayException :: CompactionFailed -> String # backtraceDesired :: CompactionFailed -> Bool #
Exception Deadlock #
Instance details Defined in GHC.Internal.IO.Exception Methods toException :: Deadlock -> SomeException # fromException :: SomeException -> Maybe Deadlock # displayException :: Deadlock -> String # backtraceDesired :: Deadlock -> Bool #
Exception ExitCode #
Instance details Defined in GHC.Internal.IO.Exception Methods toException :: ExitCode -> SomeException # fromException :: SomeException -> Maybe ExitCode # displayException :: ExitCode -> String # backtraceDesired :: ExitCode -> Bool #
Exception FixIOException #
Instance details Defined in GHC.Internal.IO.Exception Methods toException :: FixIOException -> SomeException # fromException :: SomeException -> Maybe FixIOException # displayException :: FixIOException -> String # backtraceDesired :: FixIOException -> Bool #
Exception IOException #
Instance details Defined in GHC.Internal.IO.Exception Methods toException :: IOException -> SomeException # fromException :: SomeException -> Maybe IOException # displayException :: IOException -> String # backtraceDesired :: IOException -> Bool #
Exception SomeAsyncException #
Instance details Defined in GHC.Internal.IO.Exception Methods toException :: SomeAsyncException -> SomeException # fromException :: SomeException -> Maybe SomeAsyncException # displayException :: SomeAsyncException -> String # backtraceDesired :: SomeAsyncException -> Bool #
Exception a => Exception (ExceptionWithContext a) #
Instance details Defined in GHC.Internal.Exception.Type Methods toException :: ExceptionWithContext a -> SomeException # fromException :: SomeException -> Maybe (ExceptionWithContext a) # displayException :: ExceptionWithContext a -> String # backtraceDesired :: ExceptionWithContext a -> Bool #
Exception e => Exception (NoBacktrace e) #
Instance details Defined in GHC.Internal.Exception.Type Methods toException :: NoBacktrace e -> SomeException # fromException :: SomeException -> Maybe (NoBacktrace e) # displayException :: NoBacktrace e -> String # backtraceDesired :: NoBacktrace e -> Bool #

data ExceptionWithContext a #

Constructors

ExceptionWithContext ExceptionContext a

Instances

Instances details

Exception a => Exception (ExceptionWithContext a) #
Instance details Defined in GHC.Internal.Exception.Type Methods toException :: ExceptionWithContext a -> SomeException # fromException :: SomeException -> Maybe (ExceptionWithContext a) # displayException :: ExceptionWithContext a -> String # backtraceDesired :: ExceptionWithContext a -> Bool #
Show a => Show (ExceptionWithContext a) #
Instance details Defined in GHC.Internal.Exception.Type Methods showsPrec :: Int -> ExceptionWithContext a -> ShowS show :: ExceptionWithContext a -> String showList :: [ExceptionWithContext a] -> ShowS

newtype NoBacktrace e #

Constructors

NoBacktrace e

Instances

Instances details

Exception e => Exception (NoBacktrace e) #
Instance details Defined in GHC.Internal.Exception.Type Methods toException :: NoBacktrace e -> SomeException # fromException :: SomeException -> Maybe (NoBacktrace e) # displayException :: NoBacktrace e -> String # backtraceDesired :: NoBacktrace e -> Bool #
Show e => Show (NoBacktrace e) #
Instance details Defined in GHC.Internal.Exception.Type Methods showsPrec :: Int -> NoBacktrace e -> ShowS show :: NoBacktrace e -> String showList :: [NoBacktrace e] -> ShowS

data SomeException #

Constructors

(Exception e, HasExceptionContext) => SomeException e

Instances

Instances details

Exception SomeException #
Instance details Defined in GHC.Internal.Exception.Type Methods toException :: SomeException -> SomeException # fromException :: SomeException -> Maybe SomeException # displayException :: SomeException -> String # backtraceDesired :: SomeException -> Bool #
Show SomeException #
Instance details Defined in GHC.Internal.Exception.Type Methods showsPrec :: Int -> SomeException -> ShowS show :: SomeException -> String showList :: [SomeException] -> ShowS

data WhileHandling #

Constructors

WhileHandling SomeException

Instances

Instances details

ExceptionAnnotation WhileHandling #
Instance details Defined in GHC.Internal.Exception.Type Methods displayExceptionAnnotation :: WhileHandling -> String
Show WhileHandling #
Instance details Defined in GHC.Internal.Exception.Type Methods showsPrec :: Int -> WhileHandling -> ShowS show :: WhileHandling -> String showList :: [WhileHandling] -> ShowS

data MaskingState #

Constructors

Unmasked
MaskedInterruptible
MaskedUninterruptible

Instances

Instances details

NFData MaskingState #
Instance details Defined in Control.DeepSeq Methods rnf :: MaskingState -> ()
Show MaskingState #
Instance details Defined in GHC.Internal.IO Methods showsPrec :: Int -> MaskingState -> ShowS show :: MaskingState -> String showList :: [MaskingState] -> ShowS
Eq MaskingState #
Instance details Defined in GHC.Internal.IO Methods (==) :: MaskingState -> MaskingState -> Bool (/=) :: MaskingState -> MaskingState -> Bool

data AllocationLimitExceeded #

Constructors

AllocationLimitExceeded

Instances

Instances details

Exception AllocationLimitExceeded #
Instance details Defined in GHC.Internal.IO.Exception Methods toException :: AllocationLimitExceeded -> SomeException # fromException :: SomeException -> Maybe AllocationLimitExceeded # displayException :: AllocationLimitExceeded -> String # backtraceDesired :: AllocationLimitExceeded -> Bool #
Show AllocationLimitExceeded #
Instance details Defined in GHC.Internal.IO.Exception Methods showsPrec :: Int -> AllocationLimitExceeded -> ShowS show :: AllocationLimitExceeded -> String showList :: [AllocationLimitExceeded] -> ShowS

data ArrayException #

Constructors

IndexOutOfBounds String
UndefinedElement String

Instances

Instances details

Exception ArrayException #
Instance details Defined in GHC.Internal.IO.Exception Methods toException :: ArrayException -> SomeException # fromException :: SomeException -> Maybe ArrayException # displayException :: ArrayException -> String # backtraceDesired :: ArrayException -> Bool #
Show ArrayException #
Instance details Defined in GHC.Internal.IO.Exception Methods showsPrec :: Int -> ArrayException -> ShowS show :: ArrayException -> String showList :: [ArrayException] -> ShowS
Eq ArrayException #
Instance details Defined in GHC.Internal.IO.Exception Methods (==) :: ArrayException -> ArrayException -> Bool (/=) :: ArrayException -> ArrayException -> Bool
Ord ArrayException #
Instance details Defined in GHC.Internal.IO.Exception Methods compare :: ArrayException -> ArrayException -> Ordering (<) :: ArrayException -> ArrayException -> Bool (<=) :: ArrayException -> ArrayException -> Bool (>) :: ArrayException -> ArrayException -> Bool (>=) :: ArrayException -> ArrayException -> Bool max :: ArrayException -> ArrayException -> ArrayException min :: ArrayException -> ArrayException -> ArrayException

newtype AssertionFailed #

Constructors

AssertionFailed String

Instances

Instances details

Exception AssertionFailed #
Instance details Defined in GHC.Internal.IO.Exception Methods toException :: AssertionFailed -> SomeException # fromException :: SomeException -> Maybe AssertionFailed # displayException :: AssertionFailed -> String # backtraceDesired :: AssertionFailed -> Bool #
Show AssertionFailed #
Instance details Defined in GHC.Internal.IO.Exception Methods showsPrec :: Int -> AssertionFailed -> ShowS show :: AssertionFailed -> String showList :: [AssertionFailed] -> ShowS

data AsyncException #

Constructors

StackOverflow
HeapOverflow
ThreadKilled
UserInterrupt

Instances

Instances details

Exception AsyncException #
Instance details Defined in GHC.Internal.IO.Exception Methods toException :: AsyncException -> SomeException # fromException :: SomeException -> Maybe AsyncException # displayException :: AsyncException -> String # backtraceDesired :: AsyncException -> Bool #
Show AsyncException #
Instance details Defined in GHC.Internal.IO.Exception Methods showsPrec :: Int -> AsyncException -> ShowS show :: AsyncException -> String showList :: [AsyncException] -> ShowS
Eq AsyncException #
Instance details Defined in GHC.Internal.IO.Exception Methods (==) :: AsyncException -> AsyncException -> Bool (/=) :: AsyncException -> AsyncException -> Bool
Ord AsyncException #
Instance details Defined in GHC.Internal.IO.Exception Methods compare :: AsyncException -> AsyncException -> Ordering (<) :: AsyncException -> AsyncException -> Bool (<=) :: AsyncException -> AsyncException -> Bool (>) :: AsyncException -> AsyncException -> Bool (>=) :: AsyncException -> AsyncException -> Bool max :: AsyncException -> AsyncException -> AsyncException min :: AsyncException -> AsyncException -> AsyncException

data BlockedIndefinitelyOnMVar #

Constructors

BlockedIndefinitelyOnMVar

Instances

Instances details

Exception BlockedIndefinitelyOnMVar #
Instance details Defined in GHC.Internal.IO.Exception Methods toException :: BlockedIndefinitelyOnMVar -> SomeException # fromException :: SomeException -> Maybe BlockedIndefinitelyOnMVar # displayException :: BlockedIndefinitelyOnMVar -> String # backtraceDesired :: BlockedIndefinitelyOnMVar -> Bool #
Show BlockedIndefinitelyOnMVar #
Instance details Defined in GHC.Internal.IO.Exception Methods showsPrec :: Int -> BlockedIndefinitelyOnMVar -> ShowS show :: BlockedIndefinitelyOnMVar -> String showList :: [BlockedIndefinitelyOnMVar] -> ShowS

data BlockedIndefinitelyOnSTM #

Constructors

BlockedIndefinitelyOnSTM

Instances

Instances details

Exception BlockedIndefinitelyOnSTM #
Instance details Defined in GHC.Internal.IO.Exception Methods toException :: BlockedIndefinitelyOnSTM -> SomeException # fromException :: SomeException -> Maybe BlockedIndefinitelyOnSTM # displayException :: BlockedIndefinitelyOnSTM -> String # backtraceDesired :: BlockedIndefinitelyOnSTM -> Bool #
Show BlockedIndefinitelyOnSTM #
Instance details Defined in GHC.Internal.IO.Exception Methods showsPrec :: Int -> BlockedIndefinitelyOnSTM -> ShowS show :: BlockedIndefinitelyOnSTM -> String showList :: [BlockedIndefinitelyOnSTM] -> ShowS

newtype CompactionFailed #

Constructors

CompactionFailed String

Instances

Instances details

Exception CompactionFailed #
Instance details Defined in GHC.Internal.IO.Exception Methods toException :: CompactionFailed -> SomeException # fromException :: SomeException -> Maybe CompactionFailed # displayException :: CompactionFailed -> String # backtraceDesired :: CompactionFailed -> Bool #
Show CompactionFailed #
Instance details Defined in GHC.Internal.IO.Exception Methods showsPrec :: Int -> CompactionFailed -> ShowS show :: CompactionFailed -> String showList :: [CompactionFailed] -> ShowS

data Deadlock #

Constructors

Deadlock

Instances

Instances details

Exception Deadlock #
Instance details Defined in GHC.Internal.IO.Exception Methods toException :: Deadlock -> SomeException # fromException :: SomeException -> Maybe Deadlock # displayException :: Deadlock -> String # backtraceDesired :: Deadlock -> Bool #
Show Deadlock #
Instance details Defined in GHC.Internal.IO.Exception Methods showsPrec :: Int -> Deadlock -> ShowS show :: Deadlock -> String showList :: [Deadlock] -> ShowS

data IOException #

Instances

Instances details

Exception IOException #
Instance details Defined in GHC.Internal.IO.Exception Methods toException :: IOException -> SomeException # fromException :: SomeException -> Maybe IOException # displayException :: IOException -> String # backtraceDesired :: IOException -> Bool #
Show IOException #
Instance details Defined in GHC.Internal.IO.Exception Methods showsPrec :: Int -> IOException -> ShowS show :: IOException -> String showList :: [IOException] -> ShowS
Eq IOException #
Instance details Defined in GHC.Internal.IO.Exception Methods (==) :: IOException -> IOException -> Bool (/=) :: IOException -> IOException -> Bool

data SomeAsyncException #

Constructors

Exception e => SomeAsyncException e

Instances

Instances details

Exception SomeAsyncException #
Instance details Defined in GHC.Internal.IO.Exception Methods toException :: SomeAsyncException -> SomeException # fromException :: SomeException -> Maybe SomeAsyncException # displayException :: SomeAsyncException -> String # backtraceDesired :: SomeAsyncException -> Bool #
Show SomeAsyncException #
Instance details Defined in GHC.Internal.IO.Exception Methods showsPrec :: Int -> SomeAsyncException -> ShowS show :: SomeAsyncException -> String showList :: [SomeAsyncException] -> ShowS

type Partial = HasCallStack Source #

A constraint which documents that a function is partial, and on GHC 8.0 and above produces a stack trace on failure. For example:

myHead :: Partial => [a] -> a
myHead [] = error "bad"
myHead (x:xs) = x

When using Partial with GHC 7.8 or below you need to enable the language feature ConstraintKinds, e.g. {-# LANGUAGE ConstraintKinds #-} at the top of the file.

retry :: Int -> IO a -> IO a Source #

Retry an operation at most n times (n must be positive). If the operation fails the nth time it will throw that final exception.

retry 1 (print "x")  == print "x"
retry 3 (fail "die") == fail "die"

retryBool :: Exception e => (e -> Bool) -> Int -> IO a -> IO a Source #

Retry an operation at most n times (n must be positive), while the exception value and type match a predicate. If the operation fails the nth time it will throw that final exception.

errorWithoutStackTrace :: [Char] -> a #

showException :: Show e => e -> IO String Source #

Show a value, but if the result contains exceptions, produce <Exception>. Defined as stringException . show. Particularly useful for printing exceptions to users, remembering that exceptions can themselves contain undefined values.

stringException :: String -> IO String Source #

Fully evaluate an input String. If the String contains embedded exceptions it will produce <Exception>.

stringException "test"                           == pure "test"
stringException ("test" ++ undefined)            == pure "test<Exception>"
stringException ("test" ++ undefined ++ "hello") == pure "test<Exception>"
stringException ['t','e','s','t',undefined]      == pure "test<Exception>"

errorIO :: Partial => String -> IO a Source #

An IO action that when evaluated calls error, in the IO monad. Note that while fail in IO raises an IOException, this function raises an ErrorCall exception with a call stack.

catch (errorIO "Hello") (\(ErrorCall x) -> pure x) == pure "Hello"
seq (errorIO "foo") (print 1) == print 1

assertIO :: Partial => Bool -> IO () Source #

An IO action that when evaluated calls assert in the IO monad, which throws an AssertionFailed exception if the argument is False. With optimizations enabled (and -fgnore-asserts) this function ignores its argument and does nothing.

catch (assertIO True  >> pure 1) (\(x :: AssertionFailed) -> pure 2) == pure 1
seq (assertIO False) (print 1) == print 1

Exception catching/ignoring

ignore :: IO () -> IO () Source #

Ignore any exceptions thrown by the action.

ignore (print 1)    == print 1
ignore (fail "die") == pure ()

catch_ :: IO a -> (SomeException -> IO a) -> IO a Source #

A version of catch without the Exception context, restricted to SomeException, so catches all exceptions.

handle_ :: (SomeException -> IO a) -> IO a -> IO a Source #

Like catch_ but for handle

try_ :: IO a -> IO (Either SomeException a) Source #

Like catch_ but for try

catchJust_ :: (SomeException -> Maybe b) -> IO a -> (b -> IO a) -> IO a Source #

Like catch_ but for catchJust

handleJust_ :: (SomeException -> Maybe b) -> (b -> IO a) -> IO a -> IO a Source #

Like catch_ but for handleJust

tryJust_ :: (SomeException -> Maybe b) -> IO a -> IO (Either b a) Source #

Like catch_ but for tryJust

catchBool :: Exception e => (e -> Bool) -> IO a -> (e -> IO a) -> IO a Source #

Catch an exception if the predicate passes, then call the handler with the original exception. As an example:

readFileExists x == catchBool isDoesNotExistError (readFile "myfile") (const $ pure "")

handleBool :: Exception e => (e -> Bool) -> (e -> IO a) -> IO a -> IO a Source #

Like catchBool but for handle.

tryBool :: Exception e => (e -> Bool) -> IO a -> IO (Either e a) Source #

Like catchBool but for try.