GHC.Packing.PackException

Exception type for packman library, using magic constants #include'd from a C header file shared with the foreign primitive operation code.

PackExceptions can occur at Haskell level or in the foreign primop.

All Haskell-level exceptions are cases of invalid data when reading and deserialising Serialised data:

• P_BinaryMismatch: serialised data were produced by a different executable (must be the same binary).
• P_TypeMismatch: serialised data have the wrong type
• P_ParseError: serialised data could not be parsed (from binary or text format)

The exceptions caused by the foreign primops (return codes) indicate errors at the C level. Most of them can occur when serialising data; the exception is P_GARBLED which indicates that serialised data is garbled.

Documentation

data PackException

Packing exception codes, matching error codes implemented in the runtime system or describing errors which can occur within Haskell.

Constructors

P_SUCCESS

no error, ==0. Internal code, should never be seen by users.

P_BLACKHOLE

RTS: packing hit a blackhole. Used internally, not passed to users.

P_NOBUFFER

RTS: buffer too small

P_CANNOTPACK

RTS: contains closure which cannot be packed (MVar, TVar)

P_UNSUPPORTED

RTS: contains unsupported closure type (implementation missing)

P_IMPOSSIBLE

RTS: impossible case (stack frame, message,...RTS bug!)

P_GARBLED

RTS: corrupted data for deserialisation

P_ParseError

Haskell: Packet data could not be parsed

P_BinaryMismatch

Haskell: Executable binaries do not match

P_TypeMismatch

Haskell: Packet data encodes unexpected type

Instances

Eq PackException

Ord PackException

Show PackException

Exception PackException

Typeable * PackException

decodeEx :: Int# -> PackException

decodes an Int# to a PackException. Magic constants are read from file cbits/Errors.h.

isBHExc :: Int# -> Bool

internal: checks if the given code indicates P_BLACKHOLE