GHC.IO.Exception

IO-related Exception types and functions

Documentation

data BlockedIndefinitelyOnMVar

The thread is blocked on an MVar, but there are no other references to the MVar so it can't ever continue.

Constructors

BlockedIndefinitelyOnMVar

Instances

Exception BlockedIndefinitelyOnMVar

Since: base-4.1.0.0

Defined in GHC.IO.Exception

Methods

toException :: BlockedIndefinitelyOnMVar -> SomeException

fromException :: SomeException -> Maybe BlockedIndefinitelyOnMVar

displayException :: BlockedIndefinitelyOnMVar -> String

Show BlockedIndefinitelyOnMVar

Since: base-4.1.0.0

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> BlockedIndefinitelyOnMVar -> ShowS

show :: BlockedIndefinitelyOnMVar -> String

showList :: [BlockedIndefinitelyOnMVar] -> ShowS

blockedIndefinitelyOnMVar :: SomeException

data BlockedIndefinitelyOnSTM

The thread is waiting to retry an STM transaction, but there are no other references to any TVars involved, so it can't ever continue.

Constructors

BlockedIndefinitelyOnSTM

Instances

Exception BlockedIndefinitelyOnSTM

Since: base-4.1.0.0

Defined in GHC.IO.Exception

Methods

toException :: BlockedIndefinitelyOnSTM -> SomeException

fromException :: SomeException -> Maybe BlockedIndefinitelyOnSTM

displayException :: BlockedIndefinitelyOnSTM -> String

Show BlockedIndefinitelyOnSTM

Since: base-4.1.0.0

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> BlockedIndefinitelyOnSTM -> ShowS

show :: BlockedIndefinitelyOnSTM -> String

showList :: [BlockedIndefinitelyOnSTM] -> ShowS

blockedIndefinitelyOnSTM :: SomeException

data Deadlock

There are no runnable threads, so the program is deadlocked. The Deadlock exception is raised in the main thread only.

Constructors

Deadlock

Instances

Exception Deadlock

Since: base-4.1.0.0

Defined in GHC.IO.Exception

Methods

toException :: Deadlock -> SomeException

fromException :: SomeException -> Maybe Deadlock

displayException :: Deadlock -> String

Show Deadlock

Since: base-4.1.0.0

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> Deadlock -> ShowS

show :: Deadlock -> String

showList :: [Deadlock] -> ShowS

data AllocationLimitExceeded

This thread has exceeded its allocation limit. See setAllocationCounter and enableAllocationLimit.

Since: base-4.8.0.0

Constructors

AllocationLimitExceeded

Instances

Exception AllocationLimitExceeded

Since: base-4.8.0.0

Defined in GHC.IO.Exception

Methods

toException :: AllocationLimitExceeded -> SomeException

fromException :: SomeException -> Maybe AllocationLimitExceeded

displayException :: AllocationLimitExceeded -> String

Show AllocationLimitExceeded

Since: base-4.7.1.0

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> AllocationLimitExceeded -> ShowS

show :: AllocationLimitExceeded -> String

showList :: [AllocationLimitExceeded] -> ShowS

allocationLimitExceeded :: SomeException

newtype AssertionFailed

assert was applied to False.

Constructors

AssertionFailed String

Instances

Exception AssertionFailed

Since: base-4.1.0.0

Defined in GHC.IO.Exception

Methods

toException :: AssertionFailed -> SomeException

fromException :: SomeException -> Maybe AssertionFailed

displayException :: AssertionFailed -> String

Show AssertionFailed

Since: base-4.1.0.0

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> AssertionFailed -> ShowS

show :: AssertionFailed -> String

showList :: [AssertionFailed] -> ShowS

newtype CompactionFailed

Compaction found an object that cannot be compacted. Functions cannot be compacted, nor can mutable objects or pinned objects. See compact.

Since: base-4.10.0.0

Constructors

CompactionFailed String

Instances

Exception CompactionFailed

Since: base-4.10.0.0

Defined in GHC.IO.Exception

Methods

toException :: CompactionFailed -> SomeException

fromException :: SomeException -> Maybe CompactionFailed

displayException :: CompactionFailed -> String

Show CompactionFailed

Since: base-4.10.0.0

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> CompactionFailed -> ShowS

show :: CompactionFailed -> String

showList :: [CompactionFailed] -> ShowS

cannotCompactFunction :: SomeException

cannotCompactPinned :: SomeException

cannotCompactMutable :: SomeException

data SomeAsyncException

Superclass for asynchronous exceptions.

Since: base-4.7.0.0

Constructors

forall e.Exception e => SomeAsyncException e

Instances

Exception SomeAsyncException

Since: base-4.7.0.0

Defined in GHC.IO.Exception

Methods

toException :: SomeAsyncException -> SomeException

fromException :: SomeException -> Maybe SomeAsyncException

displayException :: SomeAsyncException -> String

Show SomeAsyncException

Since: base-4.7.0.0

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> SomeAsyncException -> ShowS

show :: SomeAsyncException -> String

showList :: [SomeAsyncException] -> ShowS

asyncExceptionToException :: Exception e => e -> SomeException

Since: base-4.7.0.0

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

Since: base-4.7.0.0

data AsyncException

Asynchronous exceptions.

Constructors

StackOverflow

The current thread's stack exceeded its limit. Since an exception has been raised, the thread's stack will certainly be below its limit again, but the programmer should take remedial action immediately.

HeapOverflow

The program's heap is reaching its limit, and the program should take action to reduce the amount of live data it has. Notes:

• It is undefined which thread receives this exception. GHC currently throws this to the same thread that receives UserInterrupt, but this may change in the future.
• The GHC RTS currently can only recover from heap overflow if it detects that an explicit memory limit (set via RTS flags). has been exceeded. Currently, failure to allocate memory from the operating system results in immediate termination of the program.

ThreadKilled

This exception is raised by another thread calling killThread, or by the system if it needs to terminate the thread for some reason.

UserInterrupt

This exception is raised by default in the main thread of the program when the user requests to terminate the program via the usual mechanism(s) (e.g. Control-C in the console).

Instances

Exception AsyncException

Since: base-4.7.0.0

Defined in GHC.IO.Exception

Methods

toException :: AsyncException -> SomeException

fromException :: SomeException -> Maybe AsyncException

displayException :: AsyncException -> String

Show AsyncException

Since: base-4.1.0.0

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> AsyncException -> ShowS

show :: AsyncException -> String

showList :: [AsyncException] -> ShowS

Eq AsyncException

Since: base-4.2.0.0

Defined in GHC.IO.Exception

Methods

(==) :: AsyncException -> AsyncException -> Bool

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

Ord AsyncException

Since: base-4.2.0.0

Defined in GHC.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

stackOverflow :: SomeException

heapOverflow :: SomeException

data ArrayException

Exceptions generated by array operations

Constructors

IndexOutOfBounds String

An attempt was made to index an array outside its declared bounds.

UndefinedElement String

An attempt was made to evaluate an element of an array that had not been initialized.

Instances

Exception ArrayException

Since: base-4.1.0.0

Defined in GHC.IO.Exception

Methods

toException :: ArrayException -> SomeException

fromException :: SomeException -> Maybe ArrayException

displayException :: ArrayException -> String

Show ArrayException

Since: base-4.1.0.0

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> ArrayException -> ShowS

show :: ArrayException -> String

showList :: [ArrayException] -> ShowS

Eq ArrayException

Since: base-4.2.0.0

Defined in GHC.IO.Exception

Methods

(==) :: ArrayException -> ArrayException -> Bool

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

Ord ArrayException

Since: base-4.2.0.0

Defined in GHC.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

data ExitCode

Defines the exit codes that a program can return.

Constructors

ExitSuccess

indicates successful termination;

ExitFailure Int

indicates program failure with an exit code. The exact interpretation of the code is operating-system dependent. In particular, some values may be prohibited (e.g. 0 on a POSIX-compliant system).

Instances

Exception ExitCode

Since: base-4.1.0.0

Defined in GHC.IO.Exception

Methods

toException :: ExitCode -> SomeException

fromException :: SomeException -> Maybe ExitCode

displayException :: ExitCode -> String

Generic ExitCode

Defined in GHC.IO.Exception

Associated Types

type Rep ExitCode :: Type -> Type

Methods

from :: ExitCode -> Rep ExitCode x

to :: Rep ExitCode x -> ExitCode

Read ExitCode

Defined in GHC.IO.Exception

Methods

readsPrec :: Int -> ReadS ExitCode

readList :: ReadS [ExitCode]

readPrec :: ReadPrec ExitCode

readListPrec :: ReadPrec [ExitCode]

Show ExitCode

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> ExitCode -> ShowS

show :: ExitCode -> String

showList :: [ExitCode] -> ShowS

Eq ExitCode

Defined in GHC.IO.Exception

Methods

(==) :: ExitCode -> ExitCode -> Bool

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

Ord ExitCode

Defined in GHC.IO.Exception

Methods

compare :: ExitCode -> ExitCode -> Ordering

(<) :: ExitCode -> ExitCode -> Bool

(<=) :: ExitCode -> ExitCode -> Bool

(>) :: ExitCode -> ExitCode -> Bool

(>=) :: ExitCode -> ExitCode -> Bool

max :: ExitCode -> ExitCode -> ExitCode

min :: ExitCode -> ExitCode -> ExitCode

type Rep ExitCode

Defined in GHC.IO.Exception

type Rep ExitCode = D1 ('MetaData "ExitCode" "GHC.IO.Exception" "base" 'False) (C1 ('MetaCons "ExitSuccess" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "ExitFailure" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 Int)))

data FixIOException

The exception thrown when an infinite cycle is detected in fixIO.

Since: base-4.11.0.0

Constructors

FixIOException

Instances

Exception FixIOException

Since: base-4.11.0.0

Defined in GHC.IO.Exception

Methods

toException :: FixIOException -> SomeException

fromException :: SomeException -> Maybe FixIOException

displayException :: FixIOException -> String

Show FixIOException

Since: base-4.11.0.0

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> FixIOException -> ShowS

show :: FixIOException -> String

showList :: [FixIOException] -> ShowS

ioException :: IOException -> IO a

ioError :: IOError -> IO a

Raise an IOException in the IO monad.

type IOError = IOException

The Haskell 2010 type for exceptions in the IO monad. Any I/O operation may raise an IOException instead of returning a result. For a more general type of exception, including also those that arise in pure code, see Exception.

In Haskell 2010, this is an opaque type.

data IOException

Exceptions that occur in the IO monad. An IOException records a more specific error type, a descriptive string and maybe the handle that was used when the error was flagged.

Constructors

IOError

Fields

• ioe_handle :: Maybe Handle
• ioe_type :: IOErrorType
• ioe_location :: String
• ioe_description :: String
• ioe_errno :: Maybe CInt
• ioe_filename :: Maybe FilePath

Instances

Exception IOException

Since: base-4.1.0.0

Defined in GHC.IO.Exception

Methods

toException :: IOException -> SomeException

fromException :: SomeException -> Maybe IOException

displayException :: IOException -> String

Show IOException

Since: base-4.1.0.0

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> IOException -> ShowS

show :: IOException -> String

showList :: [IOException] -> ShowS

Eq IOException

Since: base-4.1.0.0

Defined in GHC.IO.Exception

Methods

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

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

data IOErrorType

An abstract type that contains a value for each variant of IOException.

Constructors

AlreadyExists

NoSuchThing

ResourceBusy

ResourceExhausted

EOF

IllegalOperation

PermissionDenied

UserError

UnsatisfiedConstraints

SystemError

ProtocolError

OtherError

InvalidArgument

InappropriateType

HardwareFault

UnsupportedOperation

TimeExpired

ResourceVanished

Interrupted

Instances

Show IOErrorType

Since: base-4.1.0.0

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> IOErrorType -> ShowS

show :: IOErrorType -> String

showList :: [IOErrorType] -> ShowS

Eq IOErrorType

Since: base-4.1.0.0

Defined in GHC.IO.Exception

Methods

(==) :: IOErrorType -> IOErrorType -> Bool

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

userError :: String -> IOError

Construct an IOException value with a string describing the error. The fail method of the IO instance of the Monad class raises a userError, thus:

instance Monad IO where
  ...
  fail s = ioError (userError s)

assertError :: (?callStack :: CallStack) => Bool -> a -> a

unsupportedOperation :: IOError

untangle :: Addr# -> String -> String