Modulebase-4.20.2.0Haskell2010

Foreign.C.Error

C-specific Marshalling support: Handling of C "errno" error codes.

1 type
126 values

Packagebase-4.20.2.0
Exports127
LanguageHaskell2010
LicenceBSD-3-Clause
SourceError.hs

Haskell representations of `errno` values

1 declaration

newtypenewtype Errno

Haskell representation for errno values. The implementation is deliberately exposed, to allow users to add their own definitions of Errno values.

Constructors

Errno CInt

Instances1Eq

Eq ErrnoDefined in ghc-internal-9.1003.0 · GHC.Internal.Foreign.C.Error

Common `errno` symbols

Different operating systems and/or C libraries often support different values of errno. This module defines the common values, but due to the open definition of Errno users may add definitions which are not predefined.

valueeOK :: Errno

valuee2BIG :: Errno

valueeACCES :: Errno

valueeADDRINUSE :: Errno

valueeADDRNOTAVAIL :: Errno

valueeADV :: Errno

valueeAFNOSUPPORT :: Errno

valueeAGAIN :: Errno

valueeALREADY :: Errno

valueeBADF :: Errno

valueeBADMSG :: Errno

valueeBADRPC :: Errno

valueeBUSY :: Errno

valueeCHILD :: Errno

valueeCOMM :: Errno

valueeCONNABORTED :: Errno

valueeCONNREFUSED :: Errno

valueeCONNRESET :: Errno

valueeDEADLK :: Errno

valueeDESTADDRREQ :: Errno

valueeDIRTY :: Errno

valueeDOM :: Errno

valueeDQUOT :: Errno

valueeEXIST :: Errno

valueeFAULT :: Errno

valueeFBIG :: Errno

valueeFTYPE :: Errno

valueeHOSTDOWN :: Errno

valueeHOSTUNREACH :: Errno

valueeIDRM :: Errno

valueeILSEQ :: Errno

valueeINPROGRESS :: Errno

valueeINTR :: Errno

valueeINVAL :: Errno

valueeIO :: Errno

valueeISCONN :: Errno

valueeISDIR :: Errno

valueeLOOP :: Errno

valueeMFILE :: Errno

valueeMLINK :: Errno

valueeMSGSIZE :: Errno

valueeMULTIHOP :: Errno

valueeNAMETOOLONG :: Errno

valueeNETDOWN :: Errno

valueeNETRESET :: Errno

valueeNETUNREACH :: Errno

valueeNFILE :: Errno

valueeNOBUFS :: Errno

valueeNODATA :: Errno

valueeNODEV :: Errno

valueeNOENT :: Errno

valueeNOEXEC :: Errno

valueeNOLCK :: Errno

valueeNOLINK :: Errno

valueeNOMEM :: Errno

valueeNOMSG :: Errno

valueeNONET :: Errno

valueeNOPROTOOPT :: Errno

valueeNOSPC :: Errno

valueeNOSR :: Errno

valueeNOSTR :: Errno

valueeNOSYS :: Errno

valueeNOTBLK :: Errno

valueeNOTCONN :: Errno

valueeNOTDIR :: Errno

valueeNOTEMPTY :: Errno

valueeNOTSOCK :: Errno

valueeNOTSUP :: Errno

valueeNOTTY :: Errno

valueeNXIO :: Errno

valueeOPNOTSUPP :: Errno

valueePERM :: Errno

valueePFNOSUPPORT :: Errno

valueePIPE :: Errno

valueePROCLIM :: Errno

valueePROCUNAVAIL :: Errno

valueePROGMISMATCH :: Errno

valueePROGUNAVAIL :: Errno

valueePROTO :: Errno

valueePROTONOSUPPORT :: Errno

valueePROTOTYPE :: Errno

valueeRANGE :: Errno

valueeREMCHG :: Errno

valueeREMOTE :: Errno

valueeROFS :: Errno

valueeRPCMISMATCH :: Errno

valueeRREMOTE :: Errno

valueeSHUTDOWN :: Errno

valueeSOCKTNOSUPPORT :: Errno

valueeSPIPE :: Errno

valueeSRCH :: Errno

valueeSRMNT :: Errno

valueeSTALE :: Errno

valueeTIME :: Errno

valueeTIMEDOUT :: Errno

valueeTOOMANYREFS :: Errno

valueeTXTBSY :: Errno

valueeUSERS :: Errno

valueeWOULDBLOCK :: Errno

valueeXDEV :: Errno

Errno functions

valueisValidErrno :: Errno -> Bool

Yield True if the given Errno value is valid on the system. This implies that the Eq instance of Errno is also system dependent as it is only defined for valid values of Errno.

valuegetErrno :: IO Errno

Get the current value of errno in the current thread.

On GHC, the runtime will ensure that any Haskell thread will only see "its own" errno, by saving and restoring the value when Haskell threads are scheduled across OS threads.

valueresetErrno :: IO ()

Reset the current thread's errno value to eOK.

valueerrnoToIOError

:: String
the location where the error occurred
-> Errno
the error number
-> Maybe Handle
optional handle associated with the error
-> Maybe String
optional filename associated with the error
-> IOError

Construct an IOError based on the given Errno value. The optional information can be used to improve the accuracy of error messages.

valuethrowErrno

:: String
textual description of the error location
-> IO a

Throw an IOError corresponding to the current value of getErrno.

Guards for IO operations that may fail

valuethrowErrnoIf

:: (a -> Bool)
predicate to apply to the result value of the IO operation
-> String
textual description of the location
-> IO a
the IO operation to be executed
-> IO a

Throw an IOError corresponding to the current value of getErrno if the result value of the IO action meets the given predicate.

valuethrowErrnoIf_ :: (a -> Bool) -> String -> IO a -> IO ()

as throwErrnoIf, but discards the result of the IO action after error handling.

valuethrowErrnoIfRetry :: (a -> Bool) -> String -> IO a -> IO a

as throwErrnoIf, but retry the IO action when it yields the error code eINTR - this amounts to the standard retry loop for interrupted POSIX system calls.

valuethrowErrnoIfRetry_ :: (a -> Bool) -> String -> IO a -> IO ()

as throwErrnoIfRetry, but discards the result.

valuethrowErrnoIfMinus1 :: (Eq a, Num a) => String -> IO a -> IO a

Throw an IOError corresponding to the current value of getErrno if the IO action returns a result of -1.

valuethrowErrnoIfMinus1_ :: (Eq a, Num a) => String -> IO a -> IO ()

as throwErrnoIfMinus1, but discards the result.

valuethrowErrnoIfMinus1Retry :: (Eq a, Num a) => String -> IO a -> IO a

Throw an IOError corresponding to the current value of getErrno if the IO action returns a result of -1, but retries in case of an interrupted operation.

valuethrowErrnoIfMinus1Retry_ :: (Eq a, Num a) => String -> IO a -> IO ()

as throwErrnoIfMinus1, but discards the result.

valuethrowErrnoIfNull :: String -> IO (Ptr a) -> IO (Ptr a)

Throw an IOError corresponding to the current value of getErrno if the IO action returns nullPtr.

valuethrowErrnoIfNullRetry :: String -> IO (Ptr a) -> IO (Ptr a)

Throw an IOError corresponding to the current value of getErrno if the IO action returns nullPtr, but retry in case of an interrupted operation.

valuethrowErrnoIfRetryMayBlock

:: (a -> Bool)
predicate to apply to the result value of the IO operation
-> String
textual description of the location
-> IO a
the IO operation to be executed
-> IO b
action to execute before retrying if an immediate retry would block
-> IO a

as throwErrnoIfRetry, but additionally if the operation yields the error code eAGAIN or eWOULDBLOCK, an alternative action is executed before retrying.

valuethrowErrnoIfRetryMayBlock_ :: (a -> Bool) -> String -> IO a -> IO b -> IO ()

as throwErrnoIfRetryMayBlock, but discards the result.

valuethrowErrnoIfMinus1RetryMayBlock

:: (Eq a, Num a)
=> String
-> IO a
-> IO b
-> IO a

as throwErrnoIfMinus1Retry, but checks for operations that would block.

valuethrowErrnoIfMinus1RetryMayBlock_

:: (Eq a, Num a)
=> String
-> IO a
-> IO b
-> IO ()

as throwErrnoIfMinus1RetryMayBlock, but discards the result.

valuethrowErrnoIfNullRetryMayBlock :: String -> IO (Ptr a) -> IO b -> IO (Ptr a)

as throwErrnoIfNullRetry, but checks for operations that would block.

valuethrowErrnoPath :: String -> FilePath -> IO a

as throwErrno, but exceptions include the given path when appropriate.

valuethrowErrnoPathIf :: (a -> Bool) -> String -> FilePath -> IO a -> IO a

as throwErrnoIf, but exceptions include the given path when appropriate.

valuethrowErrnoPathIf_ :: (a -> Bool) -> String -> FilePath -> IO a -> IO ()

as throwErrnoIf_, but exceptions include the given path when appropriate.

valuethrowErrnoPathIfNull :: String -> FilePath -> IO (Ptr a) -> IO (Ptr a)

as throwErrnoIfNull, but exceptions include the given path when appropriate.

valuethrowErrnoPathIfMinus1

:: (Eq a, Num a)
=> String
-> FilePath
-> IO a
-> IO a

as throwErrnoIfMinus1, but exceptions include the given path when appropriate.

valuethrowErrnoPathIfMinus1_

:: (Eq a, Num a)
=> String
-> FilePath
-> IO a
-> IO ()

as throwErrnoIfMinus1_, but exceptions include the given path when appropriate.