GHC.IO.Handle.Internals

This module defines the basic operations on I/O "handles". All of the operations defined here are independent of the underlying device.

The API of this module is unstable and not meant to be consumed by the general public. If you absolutely must depend on it, make sure to use a tight upper bound, e.g., base < 4.X rather than base < 5, because the interface can change rapidly without much warning.

Documentation

withHandle :: String -> Handle -> (Handle__ -> IO (Handle__, a)) -> IO a

withHandle' :: String -> Handle -> MVar Handle__ -> (Handle__ -> IO (Handle__, a)) -> IO a

withHandle_ :: String -> Handle -> (Handle__ -> IO a) -> IO a

withHandle__' :: String -> Handle -> MVar Handle__ -> (Handle__ -> IO Handle__) -> IO ()

withHandle_' :: String -> Handle -> MVar Handle__ -> (Handle__ -> IO a) -> IO a

withAllHandles__ :: String -> Handle -> (Handle__ -> IO Handle__) -> IO ()

wantWritableHandle :: String -> Handle -> (Handle__ -> IO a) -> IO a

wantReadableHandle :: String -> Handle -> (Handle__ -> IO (Handle__, a)) -> IO a

wantReadableHandle_ :: String -> Handle -> (Handle__ -> IO a) -> IO a

wantSeekableHandle :: String -> Handle -> (Handle__ -> IO a) -> IO a

mkHandle :: (RawIO dev, IODevice dev, BufferedIO dev, Typeable dev) => dev -> FilePath -> HandleType -> Bool -> Maybe TextEncoding -> NewlineMode -> Maybe HandleFinalizer -> Maybe (MVar Handle__) -> IO Handle

mkFileHandle

Arguments

:: (RawIO dev, IODevice dev, BufferedIO dev, Typeable dev)

=> dev

the underlying IO device, which must support IODevice, BufferedIO and Typeable

-> FilePath

a string describing the Handle, e.g. the file path for a file. Used in error messages.

-> IOMode

-> Maybe TextEncoding

-> NewlineMode

-> IO Handle

makes a new Handle

mkFileHandleNoFinalizer

Arguments

:: (RawIO dev, IODevice dev, BufferedIO dev, Typeable dev)

=> dev

the underlying IO device, which must support IODevice, BufferedIO and Typeable

-> FilePath

a string describing the Handle, e.g. the file path for a file. Used in error messages.

-> IOMode

-> Maybe TextEncoding

-> NewlineMode

-> IO Handle

makes a new Handle without a finalizer.

mkDuplexHandle :: (RawIO dev, IODevice dev, BufferedIO dev, Typeable dev) => dev -> FilePath -> Maybe TextEncoding -> NewlineMode -> IO Handle

like mkFileHandle, except that a Handle is created with two independent buffers, one for reading and one for writing. Used for full-duplex streams, such as network sockets.

mkDuplexHandleNoFinalizer :: (RawIO dev, IODevice dev, BufferedIO dev, Typeable dev) => dev -> FilePath -> Maybe TextEncoding -> NewlineMode -> IO Handle

like mkFileHandle, except that a Handle is created with two independent buffers, one for reading and one for writing. Used for full-duplex streams, such as network sockets.

addHandleFinalizer :: Handle -> HandleFinalizer -> IO ()

Add a finalizer to a Handle. Specifically, the finalizer will be added to the MVar of a file handle or the write-side MVar of a duplex handle. See Handle Finalizers for details.

openTextEncoding :: Maybe TextEncoding -> HandleType -> (forall es ds. Maybe (TextEncoder es) -> Maybe (TextDecoder ds) -> IO a) -> IO a

closeTextCodecs :: Handle__ -> IO ()

initBufferState :: HandleType -> BufferState

dEFAULT_CHAR_BUFFER_SIZE :: Int

flushBuffer :: Handle__ -> IO ()

syncs the file with the buffer, including moving the file pointer backwards in the case of a read buffer. This can fail on a non-seekable read Handle.

flushWriteBuffer :: Handle__ -> IO ()

flushCharReadBuffer :: Handle__ -> IO ()

flushCharBuffer :: Handle__ -> IO ()

flushes the Char buffer only. Works on all Handles.

flushByteReadBuffer :: Handle__ -> IO ()

flushByteWriteBuffer :: Handle__ -> IO ()

readTextDevice :: Handle__ -> CharBuffer -> IO CharBuffer

writeCharBuffer :: Handle__ -> CharBuffer -> IO ()

readTextDeviceNonBlocking :: Handle__ -> CharBuffer -> IO CharBuffer

decodeByteBuf :: Handle__ -> CharBuffer -> IO CharBuffer

augmentIOError :: IOException -> String -> Handle -> IOException

ioe_closedHandle :: IO a

ioe_semiclosedHandle :: IO a

ioe_EOF :: IO a

ioe_notReadable :: IO a

ioe_notWritable :: IO a

ioe_finalizedHandle :: FilePath -> Handle__

ioe_bufsiz :: Int -> IO a

hClose_impl :: Handle -> IO ()

This function exists temporarily to avoid an unused import warning in bytestring.

hClose_help :: Handle__ -> IO (Handle__, Maybe SomeException)

hLookAhead_ :: Handle__ -> IO Char

type HandleFinalizer = FilePath -> MVar Handle__ -> IO ()

handleFinalizer :: FilePath -> MVar Handle__ -> IO ()

debugIO :: String -> IO ()

traceIO :: String -> IO ()