    {-# LANGUAGE Trustworthy #-}
    {-# LANGUAGE NoImplicitPrelude
               , RecordWildCards
               , BangPatterns
               , NondecreasingIndentation
               , RankNTypes
      #-}
    {-# OPTIONS_GHC -Wno-unused-matches #-}
    {-# OPTIONS_GHC -Wno-name-shadowing #-}
    {-# OPTIONS_GHC -Wno-incomplete-uni-patterns #-}
    {-# OPTIONS_HADDOCK not-home #-}

    -----------------------------------------------------------------------------
    -- |
    -- Module      :  GHC.IO.Handle.Internals
    -- Copyright   :  (c) The University of Glasgow, 1994-2001
    -- License     :  see libraries/base/LICENSE
    --
    -- Maintainer  :  libraries@haskell.org
    -- Stability   :  internal
    -- Portability :  non-portable
    --
    -- This module defines the basic operations on I\/O \"handles\".  All
    -- of the operations defined here are independent of the underlying
    -- device.
    --
    -----------------------------------------------------------------------------

    module GHC.IO.Handle.Internals (
      withHandle, withHandle', withHandle_,
      withHandle__', withHandle_', withAllHandles__,
      wantWritableHandle, wantReadableHandle, wantReadableHandle_,
      wantSeekableHandle,

      mkHandle, mkFileHandle, mkDuplexHandle,
      openTextEncoding, closeTextCodecs, initBufferState,
      dEFAULT_CHAR_BUFFER_SIZE,

      flushBuffer, flushWriteBuffer, flushCharReadBuffer,
      flushCharBuffer, flushByteReadBuffer, flushByteWriteBuffer,

      readTextDevice, writeCharBuffer, readTextDeviceNonBlocking,
      decodeByteBuf,

      augmentIOError,
      ioe_closedHandle, ioe_semiclosedHandle,
      ioe_EOF, ioe_notReadable, ioe_notWritable,
      ioe_finalizedHandle, ioe_bufsiz,

      hClose_help, hLookAhead_,

      HandleFinalizer, handleFinalizer,

      debugIO, traceIO
     ) where

    import GHC.IO
    import GHC.IO.IOMode
    import GHC.IO.Encoding as Encoding
    import GHC.IO.Encoding.Types (CodeBuffer)
    import GHC.IO.Handle.Types
    import GHC.IO.Buffer
    import GHC.IO.BufferedIO (BufferedIO)
    import GHC.IO.Exception
    import GHC.IO.Device (IODevice, RawIO, SeekMode(..))
    import GHC.IO.SubSystem ((<!>), isWindowsNativeIO)
    import qualified GHC.IO.Device as IODevice
    import qualified GHC.IO.BufferedIO as Buffered

    import GHC.Conc.Sync
    import GHC.Real
    import GHC.Base
    import GHC.Exception
    import GHC.Num          ( Num(..) )
    import GHC.Show
    import GHC.IORef
    import GHC.MVar
    import Data.Typeable
    import Data.Maybe
    import Foreign
    import System.Posix.Internals hiding (FD)

    import Foreign.C

    c_DEBUG_DUMP :: Bool
    c_DEBUG_DUMP :: Bool
    c_DEBUG_DUMP = Bool
    False

    -- ---------------------------------------------------------------------------
    -- Creating a new handle

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

    newFileHandle :: FilePath -> Maybe HandleFinalizer -> Handle__ -> IO Handle
    newFileHandle :: FilePath -> Maybe HandleFinalizer -> Handle__ -> IO Handle
    newFileHandle FilePath
    filepath Maybe HandleFinalizer
    mb_finalizer Handle__
    hc = do
      MVar Handle__
    m <- Handle__ -> IO (MVar Handle__)
    forall a. a -> IO (MVar a)
    newMVar Handle__
    hc
      case Maybe HandleFinalizer
    mb_finalizer of
        Just HandleFinalizer
    finalizer -> do FilePath -> IO ()
    debugIO (FilePath -> IO ()) -> FilePath -> IO ()
    forall a b. (a -> b) -> a -> b
    $ FilePath
    "Registering finalizer: " FilePath -> FilePath -> FilePath
    forall a. [a] -> [a] -> [a]
    ++ FilePath -> FilePath
    forall a. Show a => a -> FilePath
    show FilePath
    filepath
                             MVar Handle__ -> IO () -> IO ()
    forall a. MVar a -> IO () -> IO ()
    addMVarFinalizer MVar Handle__
    m (HandleFinalizer
    finalizer FilePath
    filepath MVar Handle__
    m)
        Maybe HandleFinalizer
    Nothing        -> do FilePath -> IO ()
    debugIO (FilePath -> IO ()) -> FilePath -> IO ()
    forall a b. (a -> b) -> a -> b
    $ FilePath
    "No finalizer: " FilePath -> FilePath -> FilePath
    forall a. [a] -> [a] -> [a]
    ++ FilePath -> FilePath
    forall a. Show a => a -> FilePath
    show FilePath
    filepath
                             () -> IO ()
    forall (m :: * -> *) a. Monad m => a -> m a
    return ()
      Handle -> IO Handle
    forall (m :: * -> *) a. Monad m => a -> m a
    return (FilePath -> MVar Handle__ -> Handle
    FileHandle FilePath
    filepath MVar Handle__
    m)

    -- ---------------------------------------------------------------------------
    -- Working with Handles

    {-
    In the concurrent world, handles are locked during use.  This is done
    by wrapping an MVar around the handle which acts as a mutex over
    operations on the handle.

    To avoid races, we use the following bracketing operations.  The idea
    is to obtain the lock, do some operation and replace the lock again,
    whether the operation succeeded or failed.  We also want to handle the
    case where the thread receives an exception while processing the IO
    operation: in these cases we also want to relinquish the lock.

    There are three versions of @withHandle@: corresponding to the three
    possible combinations of:

            - the operation may side-effect the handle
            - the operation may return a result

    If the operation generates an error or an exception is raised, the
    original handle is always replaced.
    -}

    {-# INLINE withHandle #-}
    withHandle :: String -> Handle -> (Handle__ -> IO (Handle__,a)) -> IO a
    withHandle :: forall a.
    FilePath -> Handle -> (Handle__ -> IO (Handle__, a)) -> IO a
    withHandle FilePath
    fun h :: Handle
    h@(FileHandle FilePath
    _ MVar Handle__
    m)     Handle__ -> IO (Handle__, a)
    act = FilePath
    -> Handle
    -> MVar Handle__
    -> (Handle__ -> IO (Handle__, a))
    -> IO a
    forall a.
    FilePath
    -> Handle
    -> MVar Handle__
    -> (Handle__ -> IO (Handle__, a))
    -> IO a
    withHandle' FilePath
    fun Handle
    h MVar Handle__
    m Handle__ -> IO (Handle__, a)
    act
    withHandle FilePath
    fun h :: Handle
    h@(DuplexHandle FilePath
    _ MVar Handle__
    m MVar Handle__
    _) Handle__ -> IO (Handle__, a)
    act = FilePath
    -> Handle
    -> MVar Handle__
    -> (Handle__ -> IO (Handle__, a))
    -> IO a
    forall a.
    FilePath
    -> Handle
    -> MVar Handle__
    -> (Handle__ -> IO (Handle__, a))
    -> IO a
    withHandle' FilePath
    fun Handle
    h MVar Handle__
    m Handle__ -> IO (Handle__, a)
    act

    withHandle' :: String -> Handle -> MVar Handle__
       -> (Handle__ -> IO (Handle__,a)) -> IO a
    withHandle' :: forall a.
    FilePath
    -> Handle
    -> MVar Handle__
    -> (Handle__ -> IO (Handle__, a))
    -> IO a
    withHandle' FilePath
    fun Handle
    h MVar Handle__
    m Handle__ -> IO (Handle__, a)
    act =
     IO a -> IO a
    forall a. IO a -> IO a
    mask_ (IO a -> IO a) -> IO a -> IO a
    forall a b. (a -> b) -> a -> b
    $ do
       (Handle__
    h',a
    v)  <- FilePath
    -> Handle
    -> (Handle__ -> IO (Handle__, a))
    -> MVar Handle__
    -> IO (Handle__, a)
    forall a.
    FilePath -> Handle -> (Handle__ -> IO a) -> MVar Handle__ -> IO a
    do_operation FilePath
    fun Handle
    h Handle__ -> IO (Handle__, a)
    act MVar Handle__
    m
       Handle__ -> IO ()
    checkHandleInvariants Handle__
    h'
       MVar Handle__ -> Handle__ -> IO ()
    forall a. MVar a -> a -> IO ()
    putMVar MVar Handle__
    m Handle__
    h'
       a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return a
    v

    {-# INLINE withHandle_ #-}
    withHandle_ :: String -> Handle -> (Handle__ -> IO a) -> IO a
    withHandle_ :: forall a. FilePath -> Handle -> (Handle__ -> IO a) -> IO a
    withHandle_ FilePath
    fun h :: Handle
    h@(FileHandle FilePath
    _ MVar Handle__
    m)     Handle__ -> IO a
    act = FilePath -> Handle -> MVar Handle__ -> (Handle__ -> IO a) -> IO a
    forall a.
    FilePath -> Handle -> MVar Handle__ -> (Handle__ -> IO a) -> IO a
    withHandle_' FilePath
    fun Handle
    h MVar Handle__
    m Handle__ -> IO a
    act
    withHandle_ FilePath
    fun h :: Handle
    h@(DuplexHandle FilePath
    _ MVar Handle__
    m MVar Handle__
    _) Handle__ -> IO a
    act = FilePath -> Handle -> MVar Handle__ -> (Handle__ -> IO a) -> IO a
    forall a.
    FilePath -> Handle -> MVar Handle__ -> (Handle__ -> IO a) -> IO a
    withHandle_' FilePath
    fun Handle
    h MVar Handle__
    m Handle__ -> IO a
    act

    withHandle_' :: String -> Handle -> MVar Handle__ -> (Handle__ -> IO a) -> IO a
    withHandle_' :: forall a.
    FilePath -> Handle -> MVar Handle__ -> (Handle__ -> IO a) -> IO a
    withHandle_' FilePath
    fun Handle
    h MVar Handle__
    m Handle__ -> IO a
    act = FilePath
    -> Handle
    -> MVar Handle__
    -> (Handle__ -> IO (Handle__, a))
    -> IO a
    forall a.
    FilePath
    -> Handle
    -> MVar Handle__
    -> (Handle__ -> IO (Handle__, a))
    -> IO a
    withHandle' FilePath
    fun Handle
    h MVar Handle__
    m ((Handle__ -> IO (Handle__, a)) -> IO a)
    -> (Handle__ -> IO (Handle__, a)) -> IO a
    forall a b. (a -> b) -> a -> b
    $ \Handle__
    h_ -> do
                                  a
    a <- Handle__ -> IO a
    act Handle__
    h_
                                  (Handle__, a) -> IO (Handle__, a)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (Handle__
    h_,a
    a)

    withAllHandles__ :: String -> Handle -> (Handle__ -> IO Handle__) -> IO ()
    withAllHandles__ :: FilePath -> Handle -> (Handle__ -> IO Handle__) -> IO ()
    withAllHandles__ FilePath
    fun h :: Handle
    h@(FileHandle FilePath
    _ MVar Handle__
    m)     Handle__ -> IO Handle__
    act = FilePath
    -> Handle -> MVar Handle__ -> (Handle__ -> IO Handle__) -> IO ()
    withHandle__' FilePath
    fun Handle
    h MVar Handle__
    m Handle__ -> IO Handle__
    act
    withAllHandles__ FilePath
    fun h :: Handle
    h@(DuplexHandle FilePath
    _ MVar Handle__
    r MVar Handle__
    w) Handle__ -> IO Handle__
    act = do
      FilePath
    -> Handle -> MVar Handle__ -> (Handle__ -> IO Handle__) -> IO ()
    withHandle__' FilePath
    fun Handle
    h MVar Handle__
    r Handle__ -> IO Handle__
    act
      FilePath
    -> Handle -> MVar Handle__ -> (Handle__ -> IO Handle__) -> IO ()
    withHandle__' FilePath
    fun Handle
    h MVar Handle__
    w Handle__ -> IO Handle__
    act

    withHandle__' :: String -> Handle -> MVar Handle__ -> (Handle__ -> IO Handle__)
                  -> IO ()
    withHandle__' :: FilePath
    -> Handle -> MVar Handle__ -> (Handle__ -> IO Handle__) -> IO ()
    withHandle__' FilePath
    fun Handle
    h MVar Handle__
    m Handle__ -> IO Handle__
    act =
     IO () -> IO ()
    forall a. IO a -> IO a
    mask_ (IO () -> IO ()) -> IO () -> IO ()
    forall a b. (a -> b) -> a -> b
    $ do
       Handle__
    h'  <- FilePath
    -> Handle
    -> (Handle__ -> IO Handle__)
    -> MVar Handle__
    -> IO Handle__
    forall a.
    FilePath -> Handle -> (Handle__ -> IO a) -> MVar Handle__ -> IO a
    do_operation FilePath
    fun Handle
    h Handle__ -> IO Handle__
    act MVar Handle__
    m
       Handle__ -> IO ()
    checkHandleInvariants Handle__
    h'
       MVar Handle__ -> Handle__ -> IO ()
    forall a. MVar a -> a -> IO ()
    putMVar MVar Handle__
    m Handle__
    h'
       () -> IO ()
    forall (m :: * -> *) a. Monad m => a -> m a
    return ()

    do_operation :: String -> Handle -> (Handle__ -> IO a) -> MVar Handle__ -> IO a
    do_operation :: forall a.
    FilePath -> Handle -> (Handle__ -> IO a) -> MVar Handle__ -> IO a
    do_operation FilePath
    fun Handle
    h Handle__ -> IO a
    act MVar Handle__
    m = do
      Handle__
    h_ <- MVar Handle__ -> IO Handle__
    forall a. MVar a -> IO a
    takeMVar MVar Handle__
    m
      Handle__ -> IO ()
    checkHandleInvariants Handle__
    h_
      Handle__ -> IO a
    act Handle__
    h_ IO a -> (SomeException -> IO a) -> IO a
    forall e a. Exception e => IO a -> (e -> IO a) -> IO a
    `catchException` Handle__ -> SomeException -> IO a
    handler Handle__
    h_
      where
        handler :: Handle__ -> SomeException -> IO a
    handler Handle__
    h_ SomeException
    e = do
          MVar Handle__ -> Handle__ -> IO ()
    forall a. MVar a -> a -> IO ()
    putMVar MVar Handle__
    m Handle__
    h_
          case () of
            ()
    _ | Just IOException
    ioe <- SomeException -> Maybe IOException
    forall e. Exception e => SomeException -> Maybe e
    fromException SomeException
    e ->
                IOException -> IO a
    forall a. IOException -> IO a
    ioError (IOException -> FilePath -> Handle -> IOException
    augmentIOError IOException
    ioe FilePath
    fun Handle
    h)
            ()
    _ | Just SomeAsyncException
    async_ex <- SomeException -> Maybe SomeAsyncException
    forall e. Exception e => SomeException -> Maybe e
    fromException SomeException
    e -> do -- see Note [async]
                let SomeAsyncException
    _ = SomeAsyncException
    async_ex :: SomeAsyncException
                ThreadId
    t <- IO ThreadId
    myThreadId
                ThreadId -> SomeException -> IO ()
    forall e. Exception e => ThreadId -> e -> IO ()
    throwTo ThreadId
    t SomeException
    e
                FilePath -> Handle -> (Handle__ -> IO a) -> MVar Handle__ -> IO a
    forall a.
    FilePath -> Handle -> (Handle__ -> IO a) -> MVar Handle__ -> IO a
    do_operation FilePath
    fun Handle
    h Handle__ -> IO a
    act MVar Handle__
    m
            ()
    _otherwise ->
                SomeException -> IO a
    forall e a. Exception e => e -> IO a
    throwIO SomeException
    e

    -- Note [async]
    --
    -- If an asynchronous exception is raised during an I/O operation,
    -- normally it is fine to just re-throw the exception synchronously.
    -- However, if we are inside an unsafePerformIO or an
    -- unsafeInterleaveIO, this would replace the enclosing thunk with the
    -- exception raised, which is wrong (#3997).  We have to release the
    -- lock on the Handle, but what do we replace the thunk with?  What
    -- should happen when the thunk is subsequently demanded again?
    --
    -- The only sensible choice we have is to re-do the IO operation on
    -- resumption, but then we have to be careful in the IO library that
    -- this is always safe to do.  In particular we should
    --
    --    never perform any side-effects before an interruptible operation
    --
    -- because the interruptible operation may raise an asynchronous
    -- exception, which may cause the operation and its side effects to be
    -- subsequently performed again.
    --
    -- Re-doing the IO operation is achieved by:
    --   - using throwTo to re-throw the asynchronous exception asynchronously
    --     in the current thread
    --   - on resumption, it will be as if throwTo returns.  In that case, we
    --     recursively invoke the original operation (see do_operation above).
    --
    -- Interruptible operations in the I/O library are:
    --    - threadWaitRead/threadWaitWrite
    --    - fillReadBuffer/flushWriteBuffer
    --    - readTextDevice/writeTextDevice

    augmentIOError :: IOException -> String -> Handle -> IOException
    augmentIOError :: IOException -> FilePath -> Handle -> IOException
    augmentIOError ioe :: IOException
    ioe@IOError{ ioe_filename :: IOException -> Maybe FilePath
    ioe_filename = Maybe FilePath
    fp } FilePath
    fun Handle
    h
      = IOException
    ioe { ioe_handle :: Maybe Handle
    ioe_handle = Handle -> Maybe Handle
    forall a. a -> Maybe a
    Just Handle
    h, ioe_location :: FilePath
    ioe_location = FilePath
    fun, ioe_filename :: Maybe FilePath
    ioe_filename = Maybe FilePath
    filepath }
      where filepath :: Maybe FilePath
    filepath
              | Just FilePath
    _ <- Maybe FilePath
    fp = Maybe FilePath
    fp
              | Bool
    otherwise = case Handle
    h of
                              FileHandle FilePath
    path MVar Handle__
    _     -> FilePath -> Maybe FilePath
    forall a. a -> Maybe a
    Just FilePath
    path
                              DuplexHandle FilePath
    path MVar Handle__
    _ MVar Handle__
    _ -> FilePath -> Maybe FilePath
    forall a. a -> Maybe a
    Just FilePath
    path

    -- ---------------------------------------------------------------------------
    -- Wrapper for write operations.

    -- If we already have a writeable handle just run the action.
    -- If we have a read only handle we throw an exception.
    -- If we have a read/write handle in read mode we:
    -- * Seek to the unread (from the users PoV) position and
    --   change the handles buffer to a write buffer.
    wantWritableHandle :: String -> Handle -> (Handle__ -> IO a) -> IO a
    wantWritableHandle :: forall a. FilePath -> Handle -> (Handle__ -> IO a) -> IO a
    wantWritableHandle FilePath
    fun h :: Handle
    h@(FileHandle FilePath
    _ MVar Handle__
    m) Handle__ -> IO a
    act
      = FilePath -> Handle -> MVar Handle__ -> (Handle__ -> IO a) -> IO a
    forall a.
    FilePath -> Handle -> MVar Handle__ -> (Handle__ -> IO a) -> IO a
    wantWritableHandle' FilePath
    fun Handle
    h MVar Handle__
    m Handle__ -> IO a
    act
    wantWritableHandle FilePath
    fun h :: Handle
    h@(DuplexHandle FilePath
    _ MVar Handle__
    _ MVar Handle__
    m) Handle__ -> IO a
    act
      = FilePath -> Handle -> MVar Handle__ -> (Handle__ -> IO a) -> IO a
    forall a.
    FilePath -> Handle -> MVar Handle__ -> (Handle__ -> IO a) -> IO a
    wantWritableHandle' FilePath
    fun Handle
    h MVar Handle__
    m Handle__ -> IO a
    act
        -- we know it's not a ReadHandle or ReadWriteHandle, but we have to
        -- check for ClosedHandle/SemiClosedHandle. (#4808)

    wantWritableHandle'
            :: String -> Handle -> MVar Handle__
            -> (Handle__ -> IO a) -> IO a
    wantWritableHandle' :: forall a.
    FilePath -> Handle -> MVar Handle__ -> (Handle__ -> IO a) -> IO a
    wantWritableHandle' FilePath
    fun Handle
    h MVar Handle__
    m Handle__ -> IO a
    act
       = FilePath -> Handle -> MVar Handle__ -> (Handle__ -> IO a) -> IO a
    forall a.
    FilePath -> Handle -> MVar Handle__ -> (Handle__ -> IO a) -> IO a
    withHandle_' FilePath
    fun Handle
    h MVar Handle__
    m ((Handle__ -> IO a) -> Handle__ -> IO a
    forall a. (Handle__ -> IO a) -> Handle__ -> IO a
    checkWritableHandle Handle__ -> IO a
    act)

    checkWritableHandle :: (Handle__ -> IO a) -> Handle__ -> IO a
    checkWritableHandle :: forall a. (Handle__ -> IO a) -> Handle__ -> IO a
    checkWritableHandle Handle__ -> IO a
    act h_ :: Handle__
    h_@Handle__{dev
    Maybe (MVar Handle__)
    Maybe (TextEncoder enc_state)
    Maybe (TextDecoder dec_state)
    Maybe TextEncoding
    IORef (dec_state, Buffer Word8)
    IORef (Buffer Char)
    IORef (Buffer Word8)
    IORef (BufferList Char)
    BufferMode
    HandleType
    Newline
    haType :: Handle__ -> HandleType
    haOutputNL :: Handle__ -> Newline
    haOtherSide :: Handle__ -> Maybe (MVar Handle__)
    haLastDecode :: ()
    haInputNL :: Handle__ -> Newline
    haEncoder :: ()
    haDevice :: ()
    haDecoder :: ()
    haCodec :: Handle__ -> Maybe TextEncoding
    haCharBuffer :: Handle__ -> IORef (Buffer Char)
    haByteBuffer :: Handle__ -> IORef (Buffer Word8)
    haBuffers :: Handle__ -> IORef (BufferList Char)
    haBufferMode :: Handle__ -> BufferMode
    haOtherSide :: Maybe (MVar Handle__)
    haOutputNL :: Newline
    haInputNL :: Newline
    haCodec :: Maybe TextEncoding
    haDecoder :: Maybe (TextDecoder dec_state)
    haEncoder :: Maybe (TextEncoder enc_state)
    haBuffers :: IORef (BufferList Char)
    haCharBuffer :: IORef (Buffer Char)
    haLastDecode :: IORef (dec_state, Buffer Word8)
    haBufferMode :: BufferMode
    haByteBuffer :: IORef (Buffer Word8)
    haType :: HandleType
    haDevice :: dev
    ..}
      = case HandleType
    haType of
          HandleType
    ClosedHandle         -> IO a
    forall a. IO a
    ioe_closedHandle
          HandleType
    SemiClosedHandle     -> IO a
    forall a. IO a
    ioe_semiclosedHandle
          HandleType
    ReadHandle           -> IO a
    forall a. IO a
    ioe_notWritable
          HandleType
    ReadWriteHandle      -> do
            Buffer Char
    buf <- IORef (Buffer Char) -> IO (Buffer Char)
    forall a. IORef a -> IO a
    readIORef IORef (Buffer Char)
    haCharBuffer
            Bool -> IO () -> IO ()
    forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
    when (Bool -> Bool
    not (Buffer Char -> Bool
    forall e. Buffer e -> Bool
    isWriteBuffer Buffer Char
    buf)) (IO () -> IO ()) -> IO () -> IO ()
    forall a b. (a -> b) -> a -> b
    $ do
               Handle__ -> IO ()
    flushCharReadBuffer Handle__
    h_
               Handle__ -> IO ()
    flushByteReadBuffer Handle__
    h_
               Buffer Char
    buf <- IORef (Buffer Char) -> IO (Buffer Char)
    forall a. IORef a -> IO a
    readIORef IORef (Buffer Char)
    haCharBuffer
               IORef (Buffer Char) -> Buffer Char -> IO ()
    forall a. IORef a -> a -> IO ()
    writeIORef IORef (Buffer Char)
    haCharBuffer Buffer Char
    buf{ bufState :: BufferState
    bufState = BufferState
    WriteBuffer }
               Buffer Word8
    buf <- IORef (Buffer Word8) -> IO (Buffer Word8)
    forall a. IORef a -> IO a
    readIORef IORef (Buffer Word8)
    haByteBuffer
               Buffer Word8
    buf' <- dev -> Buffer Word8 -> IO (Buffer Word8)
    forall dev.
    BufferedIO dev =>
    dev -> Buffer Word8 -> IO (Buffer Word8)
    Buffered.emptyWriteBuffer dev
    haDevice Buffer Word8
    buf
               IORef (Buffer Word8) -> Buffer Word8 -> IO ()
    forall a. IORef a -> a -> IO ()
    writeIORef IORef (Buffer Word8)
    haByteBuffer Buffer Word8
    buf'
            Handle__ -> IO a
    act Handle__
    h_
          HandleType
    AppendHandle         -> Handle__ -> IO a
    act Handle__
    h_
          HandleType
    WriteHandle          -> Handle__ -> IO a
    act Handle__
    h_

    -- ---------------------------------------------------------------------------
    -- Wrapper for read operations.

    wantReadableHandle :: String -> Handle -> (Handle__ -> IO (Handle__,a)) -> IO a
    wantReadableHandle :: forall a.
    FilePath -> Handle -> (Handle__ -> IO (Handle__, a)) -> IO a
    wantReadableHandle FilePath
    fun Handle
    h Handle__ -> IO (Handle__, a)
    act =
      FilePath -> Handle -> (Handle__ -> IO (Handle__, a)) -> IO a
    forall a.
    FilePath -> Handle -> (Handle__ -> IO (Handle__, a)) -> IO a
    withHandle FilePath
    fun Handle
    h ((Handle__ -> IO (Handle__, a)) -> Handle__ -> IO (Handle__, a)
    forall a. (Handle__ -> IO a) -> Handle__ -> IO a
    checkReadableHandle Handle__ -> IO (Handle__, a)
    act)

    wantReadableHandle_ :: String -> Handle -> (Handle__ -> IO a) -> IO a
    wantReadableHandle_ :: forall a. FilePath -> Handle -> (Handle__ -> IO a) -> IO a
    wantReadableHandle_ FilePath
    fun h :: Handle
    h@(FileHandle  FilePath
    _ MVar Handle__
    m)   Handle__ -> IO a
    act
      = FilePath -> Handle -> MVar Handle__ -> (Handle__ -> IO a) -> IO a
    forall a.
    FilePath -> Handle -> MVar Handle__ -> (Handle__ -> IO a) -> IO a
    wantReadableHandle' FilePath
    fun Handle
    h MVar Handle__
    m Handle__ -> IO a
    act
    wantReadableHandle_ FilePath
    fun h :: Handle
    h@(DuplexHandle FilePath
    _ MVar Handle__
    m MVar Handle__
    _) Handle__ -> IO a
    act
      = FilePath -> Handle -> MVar Handle__ -> (Handle__ -> IO a) -> IO a
    forall a.
    FilePath -> Handle -> MVar Handle__ -> (Handle__ -> IO a) -> IO a
    wantReadableHandle' FilePath
    fun Handle
    h MVar Handle__
    m Handle__ -> IO a
    act
        -- we know it's not a WriteHandle or ReadWriteHandle, but we have to
        -- check for ClosedHandle/SemiClosedHandle. (#4808)

    wantReadableHandle'
            :: String -> Handle -> MVar Handle__
            -> (Handle__ -> IO a) -> IO a
    wantReadableHandle' :: forall a.
    FilePath -> Handle -> MVar Handle__ -> (Handle__ -> IO a) -> IO a
    wantReadableHandle' FilePath
    fun Handle
    h MVar Handle__
    m Handle__ -> IO a
    act
      = FilePath -> Handle -> MVar Handle__ -> (Handle__ -> IO a) -> IO a
    forall a.
    FilePath -> Handle -> MVar Handle__ -> (Handle__ -> IO a) -> IO a
    withHandle_' FilePath
    fun Handle
    h MVar Handle__
    m ((Handle__ -> IO a) -> Handle__ -> IO a
    forall a. (Handle__ -> IO a) -> Handle__ -> IO a
    checkReadableHandle Handle__ -> IO a
    act)

    checkReadableHandle :: (Handle__ -> IO a) -> Handle__ -> IO a
    checkReadableHandle :: forall a. (Handle__ -> IO a) -> Handle__ -> IO a
    checkReadableHandle Handle__ -> IO a
    act h_ :: Handle__
    h_@Handle__{dev
    Maybe (MVar Handle__)
    Maybe (TextEncoder enc_state)
    Maybe (TextDecoder dec_state)
    Maybe TextEncoding
    IORef (dec_state, Buffer Word8)
    IORef (Buffer Char)
    IORef (Buffer Word8)
    IORef (BufferList Char)
    BufferMode
    HandleType
    Newline
    haOtherSide :: Maybe (MVar Handle__)
    haOutputNL :: Newline
    haInputNL :: Newline
    haCodec :: Maybe TextEncoding
    haDecoder :: Maybe (TextDecoder dec_state)
    haEncoder :: Maybe (TextEncoder enc_state)
    haBuffers :: IORef (BufferList Char)
    haCharBuffer :: IORef (Buffer Char)
    haLastDecode :: IORef (dec_state, Buffer Word8)
    haBufferMode :: BufferMode
    haByteBuffer :: IORef (Buffer Word8)
    haType :: HandleType
    haDevice :: dev
    haType :: Handle__ -> HandleType
    haOutputNL :: Handle__ -> Newline
    haOtherSide :: Handle__ -> Maybe (MVar Handle__)
    haLastDecode :: ()
    haInputNL :: Handle__ -> Newline
    haEncoder :: ()
    haDevice :: ()
    haDecoder :: ()
    haCodec :: Handle__ -> Maybe TextEncoding
    haCharBuffer :: Handle__ -> IORef (Buffer Char)
    haByteBuffer :: Handle__ -> IORef (Buffer Word8)
    haBuffers :: Handle__ -> IORef (BufferList Char)
    haBufferMode :: Handle__ -> BufferMode
    ..} =
        case HandleType
    haType of
          HandleType
    ClosedHandle         -> IO a
    forall a. IO a
    ioe_closedHandle
          HandleType
    SemiClosedHandle     -> IO a
    forall a. IO a
    ioe_semiclosedHandle
          HandleType
    AppendHandle         -> IO a
    forall a. IO a
    ioe_notReadable
          HandleType
    WriteHandle          -> IO a
    forall a. IO a
    ioe_notReadable
          HandleType
    ReadWriteHandle      -> do
              -- a read/write handle and we want to read from it.  We must
              -- flush all buffered write data first.
              Buffer Word8
    bbuf <- IORef (Buffer Word8) -> IO (Buffer Word8)
    forall a. IORef a -> IO a
    readIORef IORef (Buffer Word8)
    haByteBuffer
              Bool -> IO () -> IO ()
    forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
    when (Buffer Word8 -> Bool
    forall e. Buffer e -> Bool
    isWriteBuffer Buffer Word8
    bbuf) (IO () -> IO ()) -> IO () -> IO ()
    forall a b. (a -> b) -> a -> b
    $ do
                 Bool -> IO () -> IO ()
    forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
    when (Bool -> Bool
    not (Buffer Word8 -> Bool
    forall e. Buffer e -> Bool
    isEmptyBuffer Buffer Word8
    bbuf)) (IO () -> IO ()) -> IO () -> IO ()
    forall a b. (a -> b) -> a -> b
    $ Handle__ -> IO ()
    flushByteWriteBuffer Handle__
    h_
                 Buffer Char
    cbuf' <- IORef (Buffer Char) -> IO (Buffer Char)
    forall a. IORef a -> IO a
    readIORef IORef (Buffer Char)
    haCharBuffer
                 IORef (Buffer Char) -> Buffer Char -> IO ()
    forall a. IORef a -> a -> IO ()
    writeIORef IORef (Buffer Char)
    haCharBuffer Buffer Char
    cbuf'{ bufState :: BufferState
    bufState = BufferState
    ReadBuffer }
                 Buffer Word8
    bbuf <- IORef (Buffer Word8) -> IO (Buffer Word8)
    forall a. IORef a -> IO a
    readIORef IORef (Buffer Word8)
    haByteBuffer
                 IORef (Buffer Word8) -> Buffer Word8 -> IO ()
    forall a. IORef a -> a -> IO ()
    writeIORef IORef (Buffer Word8)
    haByteBuffer Buffer Word8
    bbuf{ bufState :: BufferState
    bufState = BufferState
    ReadBuffer }
              Handle__ -> IO a
    act Handle__
    h_
          HandleType
    _other               -> Handle__ -> IO a
    act Handle__
    h_

    -- ---------------------------------------------------------------------------
    -- Wrapper for seek operations.

    wantSeekableHandle :: String -> Handle -> (Handle__ -> IO a) -> IO a
    wantSeekableHandle :: forall a. FilePath -> Handle -> (Handle__ -> IO a) -> IO a
    wantSeekableHandle FilePath
    fun h :: Handle
    h@(DuplexHandle FilePath
    _ MVar Handle__
    _ MVar Handle__
    _) Handle__ -> IO a
    _act =
      IOException -> IO a
    forall a. IOException -> IO a
    ioException (Maybe Handle
    -> IOErrorType
    -> FilePath
    -> FilePath
    -> Maybe CInt
    -> Maybe FilePath
    -> IOException
    IOError (Handle -> Maybe Handle
    forall a. a -> Maybe a
    Just Handle
    h) IOErrorType
    IllegalOperation FilePath
    fun
                       FilePath
    "handle is not seekable" Maybe CInt
    forall a. Maybe a
    Nothing Maybe FilePath
    forall a. Maybe a
    Nothing)
    wantSeekableHandle FilePath
    fun h :: Handle
    h@(FileHandle FilePath
    _ MVar Handle__
    m) Handle__ -> IO a
    act =
      FilePath -> Handle -> MVar Handle__ -> (Handle__ -> IO a) -> IO a
    forall a.
    FilePath -> Handle -> MVar Handle__ -> (Handle__ -> IO a) -> IO a
    withHandle_' FilePath
    fun Handle
    h MVar Handle__
    m ((Handle__ -> IO a) -> Handle__ -> IO a
    forall a. (Handle__ -> IO a) -> Handle__ -> IO a
    checkSeekableHandle Handle__ -> IO a
    act)

    checkSeekableHandle :: (Handle__ -> IO a) -> Handle__ -> IO a
    checkSeekableHandle :: forall a. (Handle__ -> IO a) -> Handle__ -> IO a
    checkSeekableHandle Handle__ -> IO a
    act handle_ :: Handle__
    handle_@Handle__{haDevice :: ()
    haDevice=dev
    dev} =
        case Handle__ -> HandleType
    haType Handle__
    handle_ of
          HandleType
    ClosedHandle      -> IO a
    forall a. IO a
    ioe_closedHandle
          HandleType
    SemiClosedHandle  -> IO a
    forall a. IO a
    ioe_semiclosedHandle
          HandleType
    AppendHandle      -> IO a
    forall a. IO a
    ioe_notSeekable
          HandleType
    _ -> do Bool
    b <- dev -> IO Bool
    forall a. IODevice a => a -> IO Bool
    IODevice.isSeekable dev
    dev
                  if Bool
    b then Handle__ -> IO a
    act Handle__
    handle_
                       else IO a
    forall a. IO a
    ioe_notSeekable

    -- -----------------------------------------------------------------------------
    -- Handy IOErrors

    ioe_closedHandle, ioe_semiclosedHandle, ioe_EOF,
      ioe_notReadable, ioe_notWritable, ioe_cannotFlushNotSeekable,
      ioe_notSeekable :: IO a

    ioe_closedHandle :: forall a. IO a
    ioe_closedHandle = IOException -> IO a
    forall a. IOException -> IO a
    ioException
       (Maybe Handle
    -> IOErrorType
    -> FilePath
    -> FilePath
    -> Maybe CInt
    -> Maybe FilePath
    -> IOException
    IOError Maybe Handle
    forall a. Maybe a
    Nothing IOErrorType
    IllegalOperation FilePath
    ""
            FilePath
    "handle is closed" Maybe CInt
    forall a. Maybe a
    Nothing Maybe FilePath
    forall a. Maybe a
    Nothing)
    ioe_semiclosedHandle :: forall a. IO a
    ioe_semiclosedHandle = IOException -> IO a
    forall a. IOException -> IO a
    ioException
       (Maybe Handle
    -> IOErrorType
    -> FilePath
    -> FilePath
    -> Maybe CInt
    -> Maybe FilePath
    -> IOException
    IOError Maybe Handle
    forall a. Maybe a
    Nothing IOErrorType
    IllegalOperation FilePath
    ""
            FilePath
    "handle is semi-closed" Maybe CInt
    forall a. Maybe a
    Nothing Maybe FilePath
    forall a. Maybe a
    Nothing)
    ioe_EOF :: forall a. IO a
    ioe_EOF = IOException -> IO a
    forall a. IOException -> IO a
    ioException
       (Maybe Handle
    -> IOErrorType
    -> FilePath
    -> FilePath
    -> Maybe CInt
    -> Maybe FilePath
    -> IOException
    IOError Maybe Handle
    forall a. Maybe a
    Nothing IOErrorType
    EOF FilePath
    "" FilePath
    "" Maybe CInt
    forall a. Maybe a
    Nothing Maybe FilePath
    forall a. Maybe a
    Nothing)
    ioe_notReadable :: forall a. IO a
    ioe_notReadable = IOException -> IO a
    forall a. IOException -> IO a
    ioException
       (Maybe Handle
    -> IOErrorType
    -> FilePath
    -> FilePath
    -> Maybe CInt
    -> Maybe FilePath
    -> IOException
    IOError Maybe Handle
    forall a. Maybe a
    Nothing IOErrorType
    IllegalOperation FilePath
    ""
            FilePath
    "handle is not open for reading" Maybe CInt
    forall a. Maybe a
    Nothing Maybe FilePath
    forall a. Maybe a
    Nothing)
    ioe_notWritable :: forall a. IO a
    ioe_notWritable = IOException -> IO a
    forall a. IOException -> IO a
    ioException
       (Maybe Handle
    -> IOErrorType
    -> FilePath
    -> FilePath
    -> Maybe CInt
    -> Maybe FilePath
    -> IOException
    IOError Maybe Handle
    forall a. Maybe a
    Nothing IOErrorType
    IllegalOperation FilePath
    ""
            FilePath
    "handle is not open for writing" Maybe CInt
    forall a. Maybe a
    Nothing Maybe FilePath
    forall a. Maybe a
    Nothing)
    ioe_notSeekable :: forall a. IO a
    ioe_notSeekable = IOException -> IO a
    forall a. IOException -> IO a
    ioException
       (Maybe Handle
    -> IOErrorType
    -> FilePath
    -> FilePath
    -> Maybe CInt
    -> Maybe FilePath
    -> IOException
    IOError Maybe Handle
    forall a. Maybe a
    Nothing IOErrorType
    IllegalOperation FilePath
    ""
            FilePath
    "handle is not seekable" Maybe CInt
    forall a. Maybe a
    Nothing Maybe FilePath
    forall a. Maybe a
    Nothing)
    ioe_cannotFlushNotSeekable :: forall a. IO a
    ioe_cannotFlushNotSeekable = IOException -> IO a
    forall a. IOException -> IO a
    ioException
       (Maybe Handle
    -> IOErrorType
    -> FilePath
    -> FilePath
    -> Maybe CInt
    -> Maybe FilePath
    -> IOException
    IOError Maybe Handle
    forall a. Maybe a
    Nothing IOErrorType
    IllegalOperation FilePath
    ""
          FilePath
    "cannot flush the read buffer: underlying device is not seekable"
            Maybe CInt
    forall a. Maybe a
    Nothing Maybe FilePath
    forall a. Maybe a
    Nothing)

    ioe_finalizedHandle :: FilePath -> Handle__
    ioe_finalizedHandle :: FilePath -> Handle__
    ioe_finalizedHandle FilePath
    fp = IOException -> Handle__
    forall a e. Exception e => e -> a
    throw
       (Maybe Handle
    -> IOErrorType
    -> FilePath
    -> FilePath
    -> Maybe CInt
    -> Maybe FilePath
    -> IOException
    IOError Maybe Handle
    forall a. Maybe a
    Nothing IOErrorType
    IllegalOperation FilePath
    ""
            FilePath
    "handle is finalized" Maybe CInt
    forall a. Maybe a
    Nothing (FilePath -> Maybe FilePath
    forall a. a -> Maybe a
    Just FilePath
    fp))

    ioe_bufsiz :: Int -> IO a
    ioe_bufsiz :: forall a. Int -> IO a
    ioe_bufsiz Int
    n = IOException -> IO a
    forall a. IOException -> IO a
    ioException
       (Maybe Handle
    -> IOErrorType
    -> FilePath
    -> FilePath
    -> Maybe CInt
    -> Maybe FilePath
    -> IOException
    IOError Maybe Handle
    forall a. Maybe a
    Nothing IOErrorType
    InvalidArgument FilePath
    "hSetBuffering"
            (FilePath
    "illegal buffer size " FilePath -> FilePath -> FilePath
    forall a. [a] -> [a] -> [a]
    ++ Int -> Int -> FilePath -> FilePath
    forall a. Show a => Int -> a -> FilePath -> FilePath
    showsPrec Int
    9 Int
    n []) Maybe CInt
    forall a. Maybe a
    Nothing Maybe FilePath
    forall a. Maybe a
    Nothing)
                                    -- 9 => should be parens'ified.

    -- ---------------------------------------------------------------------------
    -- Wrapper for Handle encoding/decoding.

    -- The interface for TextEncoding changed so that a TextEncoding doesn't raise
    -- an exception if it encounters an invalid sequence. Furthermore, encoding
    -- returns a reason as to why encoding stopped, letting us know if it was due
    -- to input/output underflow or an invalid sequence.
    --
    -- This code adapts this elaborated interface back to the original TextEncoding
    -- interface.
    --
    -- FIXME: it is possible that Handle code using the haDecoder/haEncoder fields
    -- could be made clearer by using the 'encode' interface directly. I have not
    -- looked into this.

    streamEncode :: BufferCodec from to state
                 -> Buffer from -> Buffer to
                 -> IO (Buffer from, Buffer to)
    streamEncode :: forall from to state.
    BufferCodec from to state
    -> Buffer from -> Buffer to -> IO (Buffer from, Buffer to)
    streamEncode BufferCodec from to state
    codec Buffer from
    from Buffer to
    to = ((CodingProgress, Buffer from, Buffer to)
     -> (Buffer from, Buffer to))
    -> IO (CodingProgress, Buffer from, Buffer to)
    -> IO (Buffer from, Buffer to)
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
    fmap (\(CodingProgress
    _, Buffer from
    from', Buffer to
    to') -> (Buffer from
    from', Buffer to
    to')) (IO (CodingProgress, Buffer from, Buffer to)
     -> IO (Buffer from, Buffer to))
    -> IO (CodingProgress, Buffer from, Buffer to)
    -> IO (Buffer from, Buffer to)
    forall a b. (a -> b) -> a -> b
    $ BufferCodec from to state -> CodeBuffer from to
    forall from to state.
    BufferCodec from to state -> CodeBuffer from to
    recoveringEncode BufferCodec from to state
    codec Buffer from
    from Buffer to
    to

    -- | Just like 'encode', but interleaves calls to 'encode' with calls to 'recover' in order to make as much progress as possible
    recoveringEncode :: BufferCodec from to state -> CodeBuffer from to
    recoveringEncode :: forall from to state.
    BufferCodec from to state -> CodeBuffer from to
    recoveringEncode BufferCodec from to state
    codec Buffer from
    from Buffer to
    to = Buffer from
    -> Buffer to -> IO (CodingProgress, Buffer from, Buffer to)
    go Buffer from
    from Buffer to
    to
      where
        go :: Buffer from
    -> Buffer to -> IO (CodingProgress, Buffer from, Buffer to)
    go Buffer from
    from Buffer to
    to = do
          (CodingProgress
    why, Buffer from
    from', Buffer to
    to') <- BufferCodec from to state
    -> Buffer from
    -> Buffer to
    -> IO (CodingProgress, Buffer from, Buffer to)
    forall from to state.
    BufferCodec from to state -> CodeBuffer from to
    encode BufferCodec from to state
    codec Buffer from
    from Buffer to
    to
          -- When we are dealing with Handles, we don't care about input/output
          -- underflow particularly, and we want to delay errors about invalid
          -- sequences as far as possible.
          case CodingProgress
    why of
            CodingProgress
    InvalidSequence | Buffer from -> Int
    forall e. Buffer e -> Int
    bufL Buffer from
    from Int -> Int -> Bool
    forall a. Eq a => a -> a -> Bool
    == Buffer from -> Int
    forall e. Buffer e -> Int
    bufL Buffer from
    from' -> do
              -- NB: it is OK to call recover here. Because we saw InvalidSequence, by the invariants
              -- on "encode" it must be the case that there is at least one elements available in the output
              -- buffer. Furthermore, clearly there is at least one element in the input buffer since we found
              -- something invalid there!
              (Buffer from
    from', Buffer to
    to') <- BufferCodec from to state
    -> Buffer from -> Buffer to -> IO (Buffer from, Buffer to)
    forall from to state.
    BufferCodec from to state
    -> Buffer from -> Buffer to -> IO (Buffer from, Buffer to)
    recover BufferCodec from to state
    codec Buffer from
    from' Buffer to
    to'
              Buffer from
    -> Buffer to -> IO (CodingProgress, Buffer from, Buffer to)
    go Buffer from
    from' Buffer to
    to'
            CodingProgress
    _ -> (CodingProgress, Buffer from, Buffer to)
    -> IO (CodingProgress, Buffer from, Buffer to)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (CodingProgress
    why, Buffer from
    from', Buffer to
    to')

    -- -----------------------------------------------------------------------------
    -- Handle Finalizers

    -- For a duplex handle, we arrange that the read side points to the write side
    -- (and hence keeps it alive if the read side is alive).  This is done by
    -- having the haOtherSide field of the read side point to the read side.
    -- The finalizer is then placed on the write side, and the handle only gets
    -- finalized once, when both sides are no longer required.

    -- NOTE about finalized handles: It's possible that a handle can be
    -- finalized and then we try to use it later, for example if the
    -- handle is referenced from another finalizer, or from a thread that
    -- has become unreferenced and then resurrected (arguably in the
    -- latter case we shouldn't finalize the Handle...).  Anyway,
    -- we try to emit a helpful message which is better than nothing.
    --
    -- [later; 8/2010] However, a program like this can yield a strange
    -- error message:
    --
    --   main = writeFile "out" loop
    --   loop = let x = x in x
    --
    -- because the main thread and the Handle are both unreachable at the
    -- same time, the Handle may get finalized before the main thread
    -- receives the NonTermination exception, and the exception handler
    -- will then report an error.  We'd rather this was not an error and
    -- the program just prints "<<loop>>".

    handleFinalizer :: FilePath -> MVar Handle__ -> IO ()
    handleFinalizer :: HandleFinalizer
    handleFinalizer FilePath
    fp MVar Handle__
    m = do
      Handle__
    handle_ <- MVar Handle__ -> IO Handle__
    forall a. MVar a -> IO a
    takeMVar MVar Handle__
    m
      (Handle__
    handle_', Maybe SomeException
    _) <- Handle__ -> IO (Handle__, Maybe SomeException)
    hClose_help Handle__
    handle_
      MVar Handle__ -> Handle__ -> IO ()
    forall a. MVar a -> a -> IO ()
    putMVar MVar Handle__
    m Handle__
    handle_'
      () -> IO ()
    forall (m :: * -> *) a. Monad m => a -> m a
    return ()

    -- ---------------------------------------------------------------------------
    -- Allocating buffers

    -- using an 8k char buffer instead of 32k improved performance for a
    -- basic "cat" program by ~30% for me.  --SDM
    dEFAULT_CHAR_BUFFER_SIZE :: Int
    dEFAULT_CHAR_BUFFER_SIZE :: Int
    dEFAULT_CHAR_BUFFER_SIZE = Int
    2048 -- 8k/sizeof(HsChar)

    getCharBuffer :: IODevice dev => dev -> BufferState
                  -> IO (IORef CharBuffer, BufferMode)
    getCharBuffer :: forall dev.
    IODevice dev =>
    dev -> BufferState -> IO (IORef (Buffer Char), BufferMode)
    getCharBuffer dev
    dev BufferState
    state = do
      Buffer Char
    buffer <- Int -> BufferState -> IO (Buffer Char)
    newCharBuffer Int
    dEFAULT_CHAR_BUFFER_SIZE BufferState
    state
      IORef (Buffer Char)
    ioref  <- Buffer Char -> IO (IORef (Buffer Char))
    forall a. a -> IO (IORef a)
    newIORef Buffer Char
    buffer
      Bool
    is_tty <- dev -> IO Bool
    forall a. IODevice a => a -> IO Bool
    IODevice.isTerminal dev
    dev

      let buffer_mode :: BufferMode
    buffer_mode
             | Bool
    is_tty    = BufferMode
    LineBuffering
             | Bool
    otherwise = Maybe Int -> BufferMode
    BlockBuffering Maybe Int
    forall a. Maybe a
    Nothing

      (IORef (Buffer Char), BufferMode)
    -> IO (IORef (Buffer Char), BufferMode)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (IORef (Buffer Char)
    ioref, BufferMode
    buffer_mode)

    mkUnBuffer :: BufferState -> IO (IORef CharBuffer, BufferMode)
    mkUnBuffer :: BufferState -> IO (IORef (Buffer Char), BufferMode)
    mkUnBuffer BufferState
    state = do
      Buffer Char
    buffer <- Int -> BufferState -> IO (Buffer Char)
    newCharBuffer Int
    dEFAULT_CHAR_BUFFER_SIZE BufferState
    state
                  --  See [note Buffer Sizing], GHC.IO.Handle.Types
      IORef (Buffer Char)
    ref <- Buffer Char -> IO (IORef (Buffer Char))
    forall a. a -> IO (IORef a)
    newIORef Buffer Char
    buffer
      (IORef (Buffer Char), BufferMode)
    -> IO (IORef (Buffer Char), BufferMode)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (IORef (Buffer Char)
    ref, BufferMode
    NoBuffering)

    -- -----------------------------------------------------------------------------
    -- Flushing buffers

    -- | 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.
    flushBuffer :: Handle__ -> IO ()
    flushBuffer :: Handle__ -> IO ()
    flushBuffer h_ :: Handle__
    h_@Handle__{dev
    Maybe (MVar Handle__)
    Maybe (TextEncoder enc_state)
    Maybe (TextDecoder dec_state)
    Maybe TextEncoding
    IORef (dec_state, Buffer Word8)
    IORef (Buffer Char)
    IORef (Buffer Word8)
    IORef (BufferList Char)
    BufferMode
    HandleType
    Newline
    haOtherSide :: Maybe (MVar Handle__)
    haOutputNL :: Newline
    haInputNL :: Newline
    haCodec :: Maybe TextEncoding
    haDecoder :: Maybe (TextDecoder dec_state)
    haEncoder :: Maybe (TextEncoder enc_state)
    haBuffers :: IORef (BufferList Char)
    haCharBuffer :: IORef (Buffer Char)
    haLastDecode :: IORef (dec_state, Buffer Word8)
    haBufferMode :: BufferMode
    haByteBuffer :: IORef (Buffer Word8)
    haType :: HandleType
    haDevice :: dev
    haType :: Handle__ -> HandleType
    haOutputNL :: Handle__ -> Newline
    haOtherSide :: Handle__ -> Maybe (MVar Handle__)
    haLastDecode :: ()
    haInputNL :: Handle__ -> Newline
    haEncoder :: ()
    haDevice :: ()
    haDecoder :: ()
    haCodec :: Handle__ -> Maybe TextEncoding
    haCharBuffer :: Handle__ -> IORef (Buffer Char)
    haByteBuffer :: Handle__ -> IORef (Buffer Word8)
    haBuffers :: Handle__ -> IORef (BufferList Char)
    haBufferMode :: Handle__ -> BufferMode
    ..} = do
      Buffer Char
    buf <- IORef (Buffer Char) -> IO (Buffer Char)
    forall a. IORef a -> IO a
    readIORef IORef (Buffer Char)
    haCharBuffer
      case Buffer Char -> BufferState
    forall e. Buffer e -> BufferState
    bufState Buffer Char
    buf of
        BufferState
    ReadBuffer  -> do
            Handle__ -> IO ()
    flushCharReadBuffer Handle__
    h_
            Handle__ -> IO ()
    flushByteReadBuffer Handle__
    h_
        BufferState
    WriteBuffer -> do
            Handle__ -> IO ()
    flushByteWriteBuffer Handle__
    h_

    -- | flushes the Char buffer only.  Works on all Handles.
    flushCharBuffer :: Handle__ -> IO ()
    flushCharBuffer :: Handle__ -> IO ()
    flushCharBuffer h_ :: Handle__
    h_@Handle__{dev
    Maybe (MVar Handle__)
    Maybe (TextEncoder enc_state)
    Maybe (TextDecoder dec_state)
    Maybe TextEncoding
    IORef (dec_state, Buffer Word8)
    IORef (Buffer Char)
    IORef (Buffer Word8)
    IORef (BufferList Char)
    BufferMode
    HandleType
    Newline
    haOtherSide :: Maybe (MVar Handle__)
    haOutputNL :: Newline
    haInputNL :: Newline
    haCodec :: Maybe TextEncoding
    haDecoder :: Maybe (TextDecoder dec_state)
    haEncoder :: Maybe (TextEncoder enc_state)
    haBuffers :: IORef (BufferList Char)
    haCharBuffer :: IORef (Buffer Char)
    haLastDecode :: IORef (dec_state, Buffer Word8)
    haBufferMode :: BufferMode
    haByteBuffer :: IORef (Buffer Word8)
    haType :: HandleType
    haDevice :: dev
    haType :: Handle__ -> HandleType
    haOutputNL :: Handle__ -> Newline
    haOtherSide :: Handle__ -> Maybe (MVar Handle__)
    haLastDecode :: ()
    haInputNL :: Handle__ -> Newline
    haEncoder :: ()
    haDevice :: ()
    haDecoder :: ()
    haCodec :: Handle__ -> Maybe TextEncoding
    haCharBuffer :: Handle__ -> IORef (Buffer Char)
    haByteBuffer :: Handle__ -> IORef (Buffer Word8)
    haBuffers :: Handle__ -> IORef (BufferList Char)
    haBufferMode :: Handle__ -> BufferMode
    ..} = do
      Buffer Char
    cbuf <- IORef (Buffer Char) -> IO (Buffer Char)
    forall a. IORef a -> IO a
    readIORef IORef (Buffer Char)
    haCharBuffer
      case Buffer Char -> BufferState
    forall e. Buffer e -> BufferState
    bufState Buffer Char
    cbuf of
        BufferState
    ReadBuffer  -> do
            Handle__ -> IO ()
    flushCharReadBuffer Handle__
    h_
        BufferState
    WriteBuffer ->
            -- Nothing to do here. Char buffer on a write Handle is always empty
            -- between Handle operations.
            -- See [note Buffer Flushing], GHC.IO.Handle.Types.
            Bool -> IO () -> IO ()
    forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
    when (Bool -> Bool
    not (Buffer Char -> Bool
    forall e. Buffer e -> Bool
    isEmptyBuffer Buffer Char
    cbuf)) (IO () -> IO ()) -> IO () -> IO ()
    forall a b. (a -> b) -> a -> b
    $
               FilePath -> IO ()
    forall a. HasCallStack => FilePath -> a
    error FilePath
    "internal IO library error: Char buffer non-empty"

    -- -----------------------------------------------------------------------------
    -- Writing data (flushing write buffers)

    -- flushWriteBuffer flushes the byte buffer iff it contains pending write
    -- data. Because the Char buffer on a write Handle is always empty between
    -- Handle operations (see [note Buffer Flushing], GHC.IO.Handle.Types),
    -- both buffers are empty after this.
    flushWriteBuffer :: Handle__ -> IO ()
    flushWriteBuffer :: Handle__ -> IO ()
    flushWriteBuffer h_ :: Handle__
    h_@Handle__{dev
    Maybe (MVar Handle__)
    Maybe (TextEncoder enc_state)
    Maybe (TextDecoder dec_state)
    Maybe TextEncoding
    IORef (dec_state, Buffer Word8)
    IORef (Buffer Char)
    IORef (Buffer Word8)
    IORef (BufferList Char)
    BufferMode
    HandleType
    Newline
    haOtherSide :: Maybe (MVar Handle__)
    haOutputNL :: Newline
    haInputNL :: Newline
    haCodec :: Maybe TextEncoding
    haDecoder :: Maybe (TextDecoder dec_state)
    haEncoder :: Maybe (TextEncoder enc_state)
    haBuffers :: IORef (BufferList Char)
    haCharBuffer :: IORef (Buffer Char)
    haLastDecode :: IORef (dec_state, Buffer Word8)
    haBufferMode :: BufferMode
    haByteBuffer :: IORef (Buffer Word8)
    haType :: HandleType
    haDevice :: dev
    haType :: Handle__ -> HandleType
    haOutputNL :: Handle__ -> Newline
    haOtherSide :: Handle__ -> Maybe (MVar Handle__)
    haLastDecode :: ()
    haInputNL :: Handle__ -> Newline
    haEncoder :: ()
    haDevice :: ()
    haDecoder :: ()
    haCodec :: Handle__ -> Maybe TextEncoding
    haCharBuffer :: Handle__ -> IORef (Buffer Char)
    haByteBuffer :: Handle__ -> IORef (Buffer Word8)
    haBuffers :: Handle__ -> IORef (BufferList Char)
    haBufferMode :: Handle__ -> BufferMode
    ..} = do
      Buffer Word8
    buf <- IORef (Buffer Word8) -> IO (Buffer Word8)
    forall a. IORef a -> IO a
    readIORef IORef (Buffer Word8)
    haByteBuffer
      Bool -> IO () -> IO ()
    forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
    when (Buffer Word8 -> Bool
    forall e. Buffer e -> Bool
    isWriteBuffer Buffer Word8
    buf) (IO () -> IO ()) -> IO () -> IO ()
    forall a b. (a -> b) -> a -> b
    $ Handle__ -> IO ()
    flushByteWriteBuffer Handle__
    h_

    flushByteWriteBuffer :: Handle__ -> IO ()
    flushByteWriteBuffer :: Handle__ -> IO ()
    flushByteWriteBuffer h_ :: Handle__
    h_@Handle__{dev
    Maybe (MVar Handle__)
    Maybe (TextEncoder enc_state)
    Maybe (TextDecoder dec_state)
    Maybe TextEncoding
    IORef (dec_state, Buffer Word8)
    IORef (Buffer Char)
    IORef (Buffer Word8)
    IORef (BufferList Char)
    BufferMode
    HandleType
    Newline
    haOtherSide :: Maybe (MVar Handle__)
    haOutputNL :: Newline
    haInputNL :: Newline
    haCodec :: Maybe TextEncoding
    haDecoder :: Maybe (TextDecoder dec_state)
    haEncoder :: Maybe (TextEncoder enc_state)
    haBuffers :: IORef (BufferList Char)
    haCharBuffer :: IORef (Buffer Char)
    haLastDecode :: IORef (dec_state, Buffer Word8)
    haBufferMode :: BufferMode
    haByteBuffer :: IORef (Buffer Word8)
    haType :: HandleType
    haDevice :: dev
    haType :: Handle__ -> HandleType
    haOutputNL :: Handle__ -> Newline
    haOtherSide :: Handle__ -> Maybe (MVar Handle__)
    haLastDecode :: ()
    haInputNL :: Handle__ -> Newline
    haEncoder :: ()
    haDevice :: ()
    haDecoder :: ()
    haCodec :: Handle__ -> Maybe TextEncoding
    haCharBuffer :: Handle__ -> IORef (Buffer Char)
    haByteBuffer :: Handle__ -> IORef (Buffer Word8)
    haBuffers :: Handle__ -> IORef (BufferList Char)
    haBufferMode :: Handle__ -> BufferMode
    ..} = do
      Buffer Word8
    bbuf <- IORef (Buffer Word8) -> IO (Buffer Word8)
    forall a. IORef a -> IO a
    readIORef IORef (Buffer Word8)
    haByteBuffer
      Bool -> IO () -> IO ()
    forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
    when (Bool -> Bool
    not (Buffer Word8 -> Bool
    forall e. Buffer e -> Bool
    isEmptyBuffer Buffer Word8
    bbuf)) (IO () -> IO ()) -> IO () -> IO ()
    forall a b. (a -> b) -> a -> b
    $ do
        Buffer Word8
    bbuf' <- dev -> Buffer Word8 -> IO (Buffer Word8)
    forall dev.
    BufferedIO dev =>
    dev -> Buffer Word8 -> IO (Buffer Word8)
    Buffered.flushWriteBuffer dev
    haDevice Buffer Word8
    bbuf
        FilePath -> IO ()
    debugIO (FilePath
    "flushByteWriteBuffer: bbuf=" FilePath -> FilePath -> FilePath
    forall a. [a] -> [a] -> [a]
    ++ Buffer Word8 -> FilePath
    forall a. Buffer a -> FilePath
    summaryBuffer Buffer Word8
    bbuf')
        IORef (Buffer Word8) -> Buffer Word8 -> IO ()
    forall a. IORef a -> a -> IO ()
    writeIORef IORef (Buffer Word8)
    haByteBuffer Buffer Word8
    bbuf'

    -- write the contents of the CharBuffer to the Handle__.
    -- The data will be encoded and pushed to the byte buffer,
    -- flushing if the buffer becomes full.
    -- Data is written to the handles current buffer offset.
    writeCharBuffer :: Handle__ -> CharBuffer -> IO ()
    writeCharBuffer :: Handle__ -> Buffer Char -> IO ()
    writeCharBuffer h_ :: Handle__
    h_@Handle__{dev
    Maybe (MVar Handle__)
    Maybe (TextEncoder enc_state)
    Maybe (TextDecoder dec_state)
    Maybe TextEncoding
    IORef (dec_state, Buffer Word8)
    IORef (Buffer Char)
    IORef (Buffer Word8)
    IORef (BufferList Char)
    BufferMode
    HandleType
    Newline
    haOtherSide :: Maybe (MVar Handle__)
    haOutputNL :: Newline
    haInputNL :: Newline
    haCodec :: Maybe TextEncoding
    haDecoder :: Maybe (TextDecoder dec_state)
    haEncoder :: Maybe (TextEncoder enc_state)
    haBuffers :: IORef (BufferList Char)
    haCharBuffer :: IORef (Buffer Char)
    haLastDecode :: IORef (dec_state, Buffer Word8)
    haBufferMode :: BufferMode
    haByteBuffer :: IORef (Buffer Word8)
    haType :: HandleType
    haDevice :: dev
    haType :: Handle__ -> HandleType
    haOutputNL :: Handle__ -> Newline
    haOtherSide :: Handle__ -> Maybe (MVar Handle__)
    haLastDecode :: ()
    haInputNL :: Handle__ -> Newline
    haEncoder :: ()
    haDevice :: ()
    haDecoder :: ()
    haCodec :: Handle__ -> Maybe TextEncoding
    haCharBuffer :: Handle__ -> IORef (Buffer Char)
    haByteBuffer :: Handle__ -> IORef (Buffer Word8)
    haBuffers :: Handle__ -> IORef (BufferList Char)
    haBufferMode :: Handle__ -> BufferMode
    ..} !Buffer Char
    cbuf = do
      --
      Buffer Word8
    bbuf <- IORef (Buffer Word8) -> IO (Buffer Word8)
    forall a. IORef a -> IO a
    readIORef IORef (Buffer Word8)
    haByteBuffer

      FilePath -> IO ()
    debugIO (FilePath
    "writeCharBuffer: cbuf=" FilePath -> FilePath -> FilePath
    forall a. [a] -> [a] -> [a]
    ++ Buffer Char -> FilePath
    forall a. Buffer a -> FilePath
    summaryBuffer Buffer Char
    cbuf FilePath -> FilePath -> FilePath
    forall a. [a] -> [a] -> [a]
    ++
            FilePath
    " bbuf=" FilePath -> FilePath -> FilePath
    forall a. [a] -> [a] -> [a]
    ++ Buffer Word8 -> FilePath
    forall a. Buffer a -> FilePath
    summaryBuffer Buffer Word8
    bbuf)

      (Buffer Char
    cbuf',Buffer Word8
    bbuf') <- case Maybe (TextEncoder enc_state)
    haEncoder of
        Maybe (TextEncoder enc_state)
    Nothing      -> Buffer Char -> Buffer Word8 -> IO (Buffer Char, Buffer Word8)
    latin1_encode Buffer Char
    cbuf Buffer Word8
    bbuf
        Just TextEncoder enc_state
    encoder -> (TextEncoder enc_state
    -> Buffer Char -> Buffer Word8 -> IO (Buffer Char, Buffer Word8)
    forall from to state.
    BufferCodec from to state
    -> Buffer from -> Buffer to -> IO (Buffer from, Buffer to)
    streamEncode TextEncoder enc_state
    encoder) Buffer Char
    cbuf Buffer Word8
    bbuf

      FilePath -> IO ()
    debugIO (FilePath
    "writeCharBuffer after encoding: cbuf=" FilePath -> FilePath -> FilePath
    forall a. [a] -> [a] -> [a]
    ++ Buffer Char -> FilePath
    forall a. Buffer a -> FilePath
    summaryBuffer Buffer Char
    cbuf' FilePath -> FilePath -> FilePath
    forall a. [a] -> [a] -> [a]
    ++
            FilePath
    " bbuf=" FilePath -> FilePath -> FilePath
    forall a. [a] -> [a] -> [a]
    ++ Buffer Word8 -> FilePath
    forall a. Buffer a -> FilePath
    summaryBuffer Buffer Word8
    bbuf')

              -- flush the byte buffer if it is full
      if Buffer Word8 -> Bool
    forall e. Buffer e -> Bool
    isFullBuffer Buffer Word8
    bbuf'
              --  or we made no progress
         Bool -> Bool -> Bool
    || Bool -> Bool
    not (Buffer Char -> Bool
    forall e. Buffer e -> Bool
    isEmptyBuffer Buffer Char
    cbuf') Bool -> Bool -> Bool
    && Buffer Char -> Int
    forall e. Buffer e -> Int
    bufL Buffer Char
    cbuf' Int -> Int -> Bool
    forall a. Eq a => a -> a -> Bool
    == Buffer Char -> Int
    forall e. Buffer e -> Int
    bufL Buffer Char
    cbuf
              -- or the byte buffer has more elements than the user wanted buffered
         Bool -> Bool -> Bool
    || (case BufferMode
    haBufferMode of
              BlockBuffering (Just Int
    s) -> Buffer Word8 -> Int
    forall e. Buffer e -> Int
    bufferElems Buffer Word8
    bbuf' Int -> Int -> Bool
    forall a. Ord a => a -> a -> Bool
    >= Int
    s
              BufferMode
    NoBuffering -> Bool
    True
              BufferMode
    _other -> Bool
    False)
        then do
          Buffer Word8
    bbuf'' <- dev -> Buffer Word8 -> IO (Buffer Word8)
    forall dev.
    BufferedIO dev =>
    dev -> Buffer Word8 -> IO (Buffer Word8)
    Buffered.flushWriteBuffer dev
    haDevice Buffer Word8
    bbuf'
          IORef (Buffer Word8) -> Buffer Word8 -> IO ()
    forall a. IORef a -> a -> IO ()
    writeIORef IORef (Buffer Word8)
    haByteBuffer Buffer Word8
    bbuf''
          FilePath -> IO ()
    debugIO (FilePath
    "writeCharBuffer after flushing: cbuf=" FilePath -> FilePath -> FilePath
    forall a. [a] -> [a] -> [a]
    ++ Buffer Word8 -> FilePath
    forall a. Buffer a -> FilePath
    summaryBuffer Buffer Word8
    bbuf'')
        else
          IORef (Buffer Word8) -> Buffer Word8 -> IO ()
    forall a. IORef a -> a -> IO ()
    writeIORef IORef (Buffer Word8)
    haByteBuffer Buffer Word8
    bbuf'

      if Bool -> Bool
    not (Buffer Char -> Bool
    forall e. Buffer e -> Bool
    isEmptyBuffer Buffer Char
    cbuf')
         then Handle__ -> Buffer Char -> IO ()
    writeCharBuffer Handle__
    h_ Buffer Char
    cbuf'
         else () -> IO ()
    forall (m :: * -> *) a. Monad m => a -> m a
    return ()

    -- -----------------------------------------------------------------------------
    -- Flushing read buffers

    -- It is always possible to flush the Char buffer back to the byte buffer.
    flushCharReadBuffer :: Handle__ -> IO ()
    flushCharReadBuffer :: Handle__ -> IO ()
    flushCharReadBuffer Handle__{dev
    Maybe (MVar Handle__)
    Maybe (TextEncoder enc_state)
    Maybe (TextDecoder dec_state)
    Maybe TextEncoding
    IORef (dec_state, Buffer Word8)
    IORef (Buffer Char)
    IORef (Buffer Word8)
    IORef (BufferList Char)
    BufferMode
    HandleType
    Newline
    haOtherSide :: Maybe (MVar Handle__)
    haOutputNL :: Newline
    haInputNL :: Newline
    haCodec :: Maybe TextEncoding
    haDecoder :: Maybe (TextDecoder dec_state)
    haEncoder :: Maybe (TextEncoder enc_state)
    haBuffers :: IORef (BufferList Char)
    haCharBuffer :: IORef (Buffer Char)
    haLastDecode :: IORef (dec_state, Buffer Word8)
    haBufferMode :: BufferMode
    haByteBuffer :: IORef (Buffer Word8)
    haType :: HandleType
    haDevice :: dev
    haType :: Handle__ -> HandleType
    haOutputNL :: Handle__ -> Newline
    haOtherSide :: Handle__ -> Maybe (MVar Handle__)
    haLastDecode :: ()
    haInputNL :: Handle__ -> Newline
    haEncoder :: ()
    haDevice :: ()
    haDecoder :: ()
    haCodec :: Handle__ -> Maybe TextEncoding
    haCharBuffer :: Handle__ -> IORef (Buffer Char)
    haByteBuffer :: Handle__ -> IORef (Buffer Word8)
    haBuffers :: Handle__ -> IORef (BufferList Char)
    haBufferMode :: Handle__ -> BufferMode
    ..} = do
      Buffer Char
    cbuf <- IORef (Buffer Char) -> IO (Buffer Char)
    forall a. IORef a -> IO a
    readIORef IORef (Buffer Char)
    haCharBuffer
      if Buffer Char -> Bool
    forall e. Buffer e -> Bool
    isWriteBuffer Buffer Char
    cbuf Bool -> Bool -> Bool
    || Buffer Char -> Bool
    forall e. Buffer e -> Bool
    isEmptyBuffer Buffer Char
    cbuf then () -> IO ()
    forall (m :: * -> *) a. Monad m => a -> m a
    return () else do

      -- haLastDecode is the byte buffer just before we did our last batch of
      -- decoding.  We're going to re-decode the bytes up to the current char,
      -- to find out where we should revert the byte buffer to.
      (dec_state
    codec_state, Buffer Word8
    bbuf0) <- IORef (dec_state, Buffer Word8) -> IO (dec_state, Buffer Word8)
    forall a. IORef a -> IO a
    readIORef IORef (dec_state, Buffer Word8)
    haLastDecode

      Buffer Char
    cbuf0 <- IORef (Buffer Char) -> IO (Buffer Char)
    forall a. IORef a -> IO a
    readIORef IORef (Buffer Char)
    haCharBuffer
      IORef (Buffer Char) -> Buffer Char -> IO ()
    forall a. IORef a -> a -> IO ()
    writeIORef IORef (Buffer Char)
    haCharBuffer Buffer Char
    cbuf0{ bufL :: Int
    bufL=Int
    0, bufR :: Int
    bufR=Int
    0 }

      -- if we haven't used any characters from the char buffer, then just
      -- re-install the old byte buffer.
      if Buffer Char -> Int
    forall e. Buffer e -> Int
    bufL Buffer Char
    cbuf0 Int -> Int -> Bool
    forall a. Eq a => a -> a -> Bool
    == Int
    0
         then do IORef (Buffer Word8) -> Buffer Word8 -> IO ()
    forall a. IORef a -> a -> IO ()
    writeIORef IORef (Buffer Word8)
    haByteBuffer Buffer Word8
    bbuf0
                 () -> IO ()
    forall (m :: * -> *) a. Monad m => a -> m a
    return ()
         else do

      case Maybe (TextDecoder dec_state)
    haDecoder of
        Maybe (TextDecoder dec_state)
    Nothing -> do
          IORef (Buffer Word8) -> Buffer Word8 -> IO ()
    forall a. IORef a -> a -> IO ()
    writeIORef IORef (Buffer Word8)
    haByteBuffer Buffer Word8
    bbuf0 { bufL :: Int
    bufL = Buffer Word8 -> Int
    forall e. Buffer e -> Int
    bufL Buffer Word8
    bbuf0 Int -> Int -> Int
    forall a. Num a => a -> a -> a
    + Buffer Char -> Int
    forall e. Buffer e -> Int
    bufL Buffer Char
    cbuf0 }
          -- no decoder: the number of bytes to decode is the same as the
          -- number of chars we have used up.

        Just TextDecoder dec_state
    decoder -> do
          FilePath -> IO ()
    debugIO (FilePath
    "flushCharReadBuffer re-decode, bbuf=" FilePath -> FilePath -> FilePath
    forall a. [a] -> [a] -> [a]
    ++ Buffer Word8 -> FilePath
    forall a. Buffer a -> FilePath
    summaryBuffer Buffer Word8
    bbuf0 FilePath -> FilePath -> FilePath
    forall a. [a] -> [a] -> [a]
    ++
                   FilePath
    " cbuf=" FilePath -> FilePath -> FilePath
    forall a. [a] -> [a] -> [a]
    ++ Buffer Char -> FilePath
    forall a. Buffer a -> FilePath
    summaryBuffer Buffer Char
    cbuf0)

          -- restore the codec state
          TextDecoder dec_state -> dec_state -> IO ()
    forall from to state. BufferCodec from to state -> state -> IO ()
    setState TextDecoder dec_state
    decoder dec_state
    codec_state

          (Buffer Word8
    bbuf1,Buffer Char
    cbuf1) <- (TextDecoder dec_state
    -> Buffer Word8 -> Buffer Char -> IO (Buffer Word8, Buffer Char)
    forall from to state.
    BufferCodec from to state
    -> Buffer from -> Buffer to -> IO (Buffer from, Buffer to)
    streamEncode TextDecoder dec_state
    decoder) Buffer Word8
    bbuf0
                                   Buffer Char
    cbuf0{ bufL :: Int
    bufL=Int
    0, bufR :: Int
    bufR=Int
    0, bufSize :: Int
    bufSize = Buffer Char -> Int
    forall e. Buffer e -> Int
    bufL Buffer Char
    cbuf0 }

          -- We should not need to update the offset here. The bytebuffer contains the
          -- offset for the next read after it's used up. But this function only flushes
          -- the char buffer.
          -- let bbuf2 = bbuf1 -- {bufOffset = bufOffset bbuf1 - fromIntegral (bufL bbuf1)}
          -- debugIO ("finished, bbuf=" ++ summaryBuffer bbuf2 ++
          --          " cbuf=" ++ summaryBuffer cbuf1)

          IORef (Buffer Word8) -> Buffer Word8 -> IO ()
    forall a. IORef a -> a -> IO ()
    writeIORef IORef (Buffer Word8)
    haByteBuffer Buffer Word8
    bbuf1

    -- When flushing the byte read buffer, we seek backwards by the number
    -- of characters in the buffer.  The file descriptor must therefore be
    -- seekable: attempting to flush the read buffer on an unseekable
    -- handle is not allowed.

    flushByteReadBuffer :: Handle__ -> IO ()
    flushByteReadBuffer :: Handle__ -> IO ()
    flushByteReadBuffer h_ :: Handle__
    h_@Handle__{dev
    Maybe (MVar Handle__)
    Maybe (TextEncoder enc_state)
    Maybe (TextDecoder dec_state)
    Maybe TextEncoding
    IORef (dec_state, Buffer Word8)
    IORef (Buffer Char)
    IORef (Buffer Word8)
    IORef (BufferList Char)
    BufferMode
    HandleType
    Newline
    haOtherSide :: Maybe (MVar Handle__)
    haOutputNL :: Newline
    haInputNL :: Newline
    haCodec :: Maybe TextEncoding
    haDecoder :: Maybe (TextDecoder dec_state)
    haEncoder :: Maybe (TextEncoder enc_state)
    haBuffers :: IORef (BufferList Char)
    haCharBuffer :: IORef (Buffer Char)
    haLastDecode :: IORef (dec_state, Buffer Word8)
    haBufferMode :: BufferMode
    haByteBuffer :: IORef (Buffer Word8)
    haType :: HandleType
    haDevice :: dev
    haType :: Handle__ -> HandleType
    haOutputNL :: Handle__ -> Newline
    haOtherSide :: Handle__ -> Maybe (MVar Handle__)
    haLastDecode :: ()
    haInputNL :: Handle__ -> Newline
    haEncoder :: ()
    haDevice :: ()
    haDecoder :: ()
    haCodec :: Handle__ -> Maybe TextEncoding
    haCharBuffer :: Handle__ -> IORef (Buffer Char)
    haByteBuffer :: Handle__ -> IORef (Buffer Word8)
    haBuffers :: Handle__ -> IORef (BufferList Char)
    haBufferMode :: Handle__ -> BufferMode
    ..} = do
      Buffer Word8
    bbuf <- IORef (Buffer Word8) -> IO (Buffer Word8)
    forall a. IORef a -> IO a
    readIORef IORef (Buffer Word8)
    haByteBuffer

      if Buffer Word8 -> Bool
    forall e. Buffer e -> Bool
    isEmptyBuffer Buffer Word8
    bbuf then () -> IO ()
    forall (m :: * -> *) a. Monad m => a -> m a
    return () else do

      Bool
    seekable <- dev -> IO Bool
    forall a. IODevice a => a -> IO Bool
    IODevice.isSeekable dev
    haDevice
      Bool -> IO () -> IO ()
    forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
    when (Bool -> Bool
    not Bool
    seekable) (IO () -> IO ()) -> IO () -> IO ()
    forall a b. (a -> b) -> a -> b
    $ IO ()
    forall a. IO a
    ioe_cannotFlushNotSeekable

      let seek :: Int
    seek = Int -> Int
    forall a. Num a => a -> a
    negate (Buffer Word8 -> Int
    forall e. Buffer e -> Int
    bufR Buffer Word8
    bbuf Int -> Int -> Int
    forall a. Num a => a -> a -> a
    - Buffer Word8 -> Int
    forall e. Buffer e -> Int
    bufL Buffer Word8
    bbuf)
      let offset :: Word64
    offset = Buffer Word8 -> Word64
    forall e. Buffer e -> Word64
    bufOffset Buffer Word8
    bbuf Word64 -> Word64 -> Word64
    forall a. Num a => a -> a -> a
    - Int -> Word64
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral (Buffer Word8 -> Int
    forall e. Buffer e -> Int
    bufR Buffer Word8
    bbuf Int -> Int -> Int
    forall a. Num a => a -> a -> a
    - Buffer Word8 -> Int
    forall e. Buffer e -> Int
    bufL Buffer Word8
    bbuf)

      FilePath -> IO ()
    debugIO (FilePath
    "flushByteReadBuffer: new file offset = " FilePath -> FilePath -> FilePath
    forall a. [a] -> [a] -> [a]
    ++ Int -> FilePath
    forall a. Show a => a -> FilePath
    show Int
    seek)
      FilePath -> IO ()
    debugIO (FilePath
    "flushByteReadBuffer: " FilePath -> FilePath -> FilePath
    forall a. [a] -> [a] -> [a]
    ++ Buffer Word8 -> FilePath
    forall a. Buffer a -> FilePath
    summaryBuffer Buffer Word8
    bbuf)

      let mIOSeek :: IO Integer
    mIOSeek   = dev -> SeekMode -> Integer -> IO Integer
    forall a. IODevice a => a -> SeekMode -> Integer -> IO Integer
    IODevice.seek dev
    haDevice SeekMode
    RelativeSeek (Int -> Integer
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral Int
    seek)
      -- win-io doesn't need this, but it allows us to error out on invalid offsets
      let winIOSeek :: IO Integer
    winIOSeek = dev -> SeekMode -> Integer -> IO Integer
    forall a. IODevice a => a -> SeekMode -> Integer -> IO Integer
    IODevice.seek dev
    haDevice SeekMode
    AbsoluteSeek (Word64 -> Integer
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral Word64
    offset)

      Integer
    _ <- IO Integer
    mIOSeek IO Integer -> IO Integer -> IO Integer
    forall a. a -> a -> a
    <!> IO Integer
    winIOSeek  -- execute one of these two seek functions

      IORef (Buffer Word8) -> Buffer Word8 -> IO ()
    forall a. IORef a -> a -> IO ()
    writeIORef IORef (Buffer Word8)
    haByteBuffer Buffer Word8
    bbuf{ bufL :: Int
    bufL=Int
    0, bufR :: Int
    bufR=Int
    0, bufOffset :: Word64
    bufOffset=Word64
    offset }

    -- ----------------------------------------------------------------------------
    -- Making Handles

    {- Note [Making offsets for append]
       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

      The WINIO subysstem keeps track of offsets for handles
      on the Haskell side of things instead of letting the OS
      handle it. This requires us to establish the correct offset
      for a handle on creation. This is usually zero but slightly
      more tedious for append modes. There we fall back on IODevice
      functionality to establish the size of the file and then set
      the offset accordingly. This is only required for WINIO.
    -}

    mkHandle :: (RawIO dev, IODevice dev, BufferedIO dev, Typeable dev) => dev
             -> FilePath
             -> HandleType
             -> Bool                     -- buffered?
             -> Maybe TextEncoding
             -> NewlineMode
             -> Maybe HandleFinalizer
             -> Maybe (MVar Handle__)
             -> IO Handle
    mkHandle :: forall dev.
    (RawIO dev, IODevice dev, BufferedIO dev, Typeable dev) =>
    dev
    -> FilePath
    -> HandleType
    -> Bool
    -> Maybe TextEncoding
    -> NewlineMode
    -> Maybe HandleFinalizer
    -> Maybe (MVar Handle__)
    -> IO Handle
    mkHandle dev
    dev FilePath
    filepath HandleType
    ha_type Bool
    buffered Maybe TextEncoding
    mb_codec NewlineMode
    nl Maybe HandleFinalizer
    finalizer Maybe (MVar Handle__)
    other_side =
       Maybe TextEncoding
    -> HandleType
    -> (forall es ds.
        Maybe (TextEncoder es) -> Maybe (TextDecoder ds) -> IO Handle)
    -> IO Handle
    forall a.
    Maybe TextEncoding
    -> HandleType
    -> (forall es ds.
        Maybe (TextEncoder es) -> Maybe (TextDecoder ds) -> IO a)
    -> IO a
    openTextEncoding Maybe TextEncoding
    mb_codec HandleType
    ha_type ((forall es ds.
      Maybe (TextEncoder es) -> Maybe (TextDecoder ds) -> IO Handle)
     -> IO Handle)
    -> (forall es ds.
        Maybe (TextEncoder es) -> Maybe (TextDecoder ds) -> IO Handle)
    -> IO Handle
    forall a b. (a -> b) -> a -> b
    $ \ Maybe (TextEncoder es)
    mb_encoder Maybe (TextDecoder ds)
    mb_decoder -> do

       let !buf_state :: BufferState
    buf_state = HandleType -> BufferState
    initBufferState HandleType
    ha_type
       !Buffer Word8
    bbuf_no_offset <- (dev -> BufferState -> IO (Buffer Word8)
    forall dev.
    BufferedIO dev =>
    dev -> BufferState -> IO (Buffer Word8)
    Buffered.newBuffer dev
    dev BufferState
    buf_state)
       !Word64
    buf_offset <- IO Word64
    initHandleOffset
       let !bbuf :: Buffer Word8
    bbuf = Buffer Word8
    bbuf_no_offset { bufOffset :: Word64
    bufOffset = Word64
    buf_offset}

       IORef (Buffer Word8)
    bbufref <- Buffer Word8 -> IO (IORef (Buffer Word8))
    forall a. a -> IO (IORef a)
    newIORef Buffer Word8
    bbuf
       IORef (ds, Buffer Word8)
    last_decode <- (ds, Buffer Word8) -> IO (IORef (ds, Buffer Word8))
    forall a. a -> IO (IORef a)
    newIORef (FilePath -> ds
    forall a. FilePath -> a
    errorWithoutStackTrace FilePath
    "codec_state", Buffer Word8
    bbuf)

       (IORef (Buffer Char)
    cbufref,BufferMode
    bmode) <-
             if Bool
    buffered then dev -> BufferState -> IO (IORef (Buffer Char), BufferMode)
    forall dev.
    IODevice dev =>
    dev -> BufferState -> IO (IORef (Buffer Char), BufferMode)
    getCharBuffer dev
    dev BufferState
    buf_state
                         else BufferState -> IO (IORef (Buffer Char), BufferMode)
    mkUnBuffer BufferState
    buf_state

       IORef (BufferList Char)
    spares <- BufferList Char -> IO (IORef (BufferList Char))
    forall a. a -> IO (IORef a)
    newIORef BufferList Char
    forall e. BufferList e
    BufferListNil
       FilePath -> IO ()
    debugIO (FilePath -> IO ()) -> FilePath -> IO ()
    forall a b. (a -> b) -> a -> b
    $ FilePath
    "making handle for " FilePath -> FilePath -> FilePath
    forall a. [a] -> [a] -> [a]
    ++ FilePath
    filepath
       FilePath -> Maybe HandleFinalizer -> Handle__ -> IO Handle
    newFileHandle FilePath
    filepath Maybe HandleFinalizer
    finalizer
                (Handle__ :: forall dev enc_state dec_state.
    (RawIO dev, IODevice dev, BufferedIO dev, Typeable dev) =>
    dev
    -> HandleType
    -> IORef (Buffer Word8)
    -> BufferMode
    -> IORef (dec_state, Buffer Word8)
    -> IORef (Buffer Char)
    -> IORef (BufferList Char)
    -> Maybe (TextEncoder enc_state)
    -> Maybe (TextDecoder dec_state)
    -> Maybe TextEncoding
    -> Newline
    -> Newline
    -> Maybe (MVar Handle__)
    -> Handle__
    Handle__ { haDevice :: dev
    haDevice = dev
    dev,
                            haType :: HandleType
    haType = HandleType
    ha_type,
                            haBufferMode :: BufferMode
    haBufferMode = BufferMode
    bmode,
                            haByteBuffer :: IORef (Buffer Word8)
    haByteBuffer = IORef (Buffer Word8)
    bbufref,
                            haLastDecode :: IORef (ds, Buffer Word8)
    haLastDecode = IORef (ds, Buffer Word8)
    last_decode,
                            haCharBuffer :: IORef (Buffer Char)
    haCharBuffer = IORef (Buffer Char)
    cbufref,
                            haBuffers :: IORef (BufferList Char)
    haBuffers = IORef (BufferList Char)
    spares,
                            haEncoder :: Maybe (TextEncoder es)
    haEncoder = Maybe (TextEncoder es)
    mb_encoder,
                            haDecoder :: Maybe (TextDecoder ds)
    haDecoder = Maybe (TextDecoder ds)
    mb_decoder,
                            haCodec :: Maybe TextEncoding
    haCodec = Maybe TextEncoding
    mb_codec,
                            haInputNL :: Newline
    haInputNL = NewlineMode -> Newline
    inputNL NewlineMode
    nl,
                            haOutputNL :: Newline
    haOutputNL = NewlineMode -> Newline
    outputNL NewlineMode
    nl,
                            haOtherSide :: Maybe (MVar Handle__)
    haOtherSide = Maybe (MVar Handle__)
    other_side
                          })
      where
        -- See Note [Making offsets for append]
        initHandleOffset :: IO Word64
    initHandleOffset
          | HandleType -> Bool
    isAppendHandleType HandleType
    ha_type
          , Bool
    isWindowsNativeIO = do
              Integer
    size <- dev -> IO Integer
    forall a. IODevice a => a -> IO Integer
    IODevice.getSize dev
    dev
              Word64 -> IO Word64
    forall (m :: * -> *) a. Monad m => a -> m a
    return (Integer -> Word64
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral Integer
    size :: Word64)
          | Bool
    otherwise = Word64 -> IO Word64
    forall (m :: * -> *) a. Monad m => a -> m a
    return Word64
    0

    -- | makes a new 'Handle'
    mkFileHandle :: (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
                        -- The mode in which the 'Handle' is to be used
                 -> Maybe TextEncoding
                        -- Create the 'Handle' with no text encoding?
                 -> NewlineMode
                        -- Translate newlines?
                 -> IO Handle
    mkFileHandle :: forall dev.
    (RawIO dev, IODevice dev, BufferedIO dev, Typeable dev) =>
    dev
    -> FilePath
    -> IOMode
    -> Maybe TextEncoding
    -> NewlineMode
    -> IO Handle
    mkFileHandle dev
    dev FilePath
    filepath IOMode
    iomode Maybe TextEncoding
    mb_codec NewlineMode
    tr_newlines = do
       dev
    -> FilePath
    -> HandleType
    -> Bool
    -> Maybe TextEncoding
    -> NewlineMode
    -> Maybe HandleFinalizer
    -> Maybe (MVar Handle__)
    -> IO Handle
    forall dev.
    (RawIO dev, IODevice dev, BufferedIO dev, Typeable dev) =>
    dev
    -> FilePath
    -> HandleType
    -> Bool
    -> Maybe TextEncoding
    -> NewlineMode
    -> Maybe HandleFinalizer
    -> Maybe (MVar Handle__)
    -> IO Handle
    mkHandle dev
    dev FilePath
    filepath (IOMode -> HandleType
    ioModeToHandleType IOMode
    iomode) Bool
    True{-buffered-} Maybe TextEncoding
    mb_codec
                NewlineMode
    tr_newlines
                (HandleFinalizer -> Maybe HandleFinalizer
    forall a. a -> Maybe a
    Just HandleFinalizer
    handleFinalizer) Maybe (MVar Handle__)
    forall a. Maybe a
    Nothing{-other_side-}

    -- | 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.
    mkDuplexHandle :: (RawIO dev, IODevice dev, BufferedIO dev, Typeable dev) => dev
                   -> FilePath -> Maybe TextEncoding -> NewlineMode -> IO Handle
    mkDuplexHandle :: forall dev.
    (RawIO dev, IODevice dev, BufferedIO dev, Typeable dev) =>
    dev -> FilePath -> Maybe TextEncoding -> NewlineMode -> IO Handle
    mkDuplexHandle dev
    dev FilePath
    filepath Maybe TextEncoding
    mb_codec NewlineMode
    tr_newlines = do

      write_side :: Handle
    write_side@(FileHandle FilePath
    _ MVar Handle__
    write_m) <-
           dev
    -> FilePath
    -> HandleType
    -> Bool
    -> Maybe TextEncoding
    -> NewlineMode
    -> Maybe HandleFinalizer
    -> Maybe (MVar Handle__)
    -> IO Handle
    forall dev.
    (RawIO dev, IODevice dev, BufferedIO dev, Typeable dev) =>
    dev
    -> FilePath
    -> HandleType
    -> Bool
    -> Maybe TextEncoding
    -> NewlineMode
    -> Maybe HandleFinalizer
    -> Maybe (MVar Handle__)
    -> IO Handle
    mkHandle dev
    dev FilePath
    filepath HandleType
    WriteHandle Bool
    True Maybe TextEncoding
    mb_codec
                            NewlineMode
    tr_newlines
                            (HandleFinalizer -> Maybe HandleFinalizer
    forall a. a -> Maybe a
    Just HandleFinalizer
    handleFinalizer)
                            Maybe (MVar Handle__)
    forall a. Maybe a
    Nothing -- no othersie

      read_side :: Handle
    read_side@(FileHandle FilePath
    _ MVar Handle__
    read_m) <-
          dev
    -> FilePath
    -> HandleType
    -> Bool
    -> Maybe TextEncoding
    -> NewlineMode
    -> Maybe HandleFinalizer
    -> Maybe (MVar Handle__)
    -> IO Handle
    forall dev.
    (RawIO dev, IODevice dev, BufferedIO dev, Typeable dev) =>
    dev
    -> FilePath
    -> HandleType
    -> Bool
    -> Maybe TextEncoding
    -> NewlineMode
    -> Maybe HandleFinalizer
    -> Maybe (MVar Handle__)
    -> IO Handle
    mkHandle dev
    dev FilePath
    filepath HandleType
    ReadHandle Bool
    True Maybe TextEncoding
    mb_codec
                            NewlineMode
    tr_newlines
                            Maybe HandleFinalizer
    forall a. Maybe a
    Nothing -- no finalizer
                            (MVar Handle__ -> Maybe (MVar Handle__)
    forall a. a -> Maybe a
    Just MVar Handle__
    write_m)

      Handle -> IO Handle
    forall (m :: * -> *) a. Monad m => a -> m a
    return (FilePath -> MVar Handle__ -> MVar Handle__ -> Handle
    DuplexHandle FilePath
    filepath MVar Handle__
    read_m MVar Handle__
    write_m)

    ioModeToHandleType :: IOMode -> HandleType
    ioModeToHandleType :: IOMode -> HandleType
    ioModeToHandleType IOMode
    ReadMode      = HandleType
    ReadHandle
    ioModeToHandleType IOMode
    WriteMode     = HandleType
    WriteHandle
    ioModeToHandleType IOMode
    ReadWriteMode = HandleType
    ReadWriteHandle
    ioModeToHandleType IOMode
    AppendMode    = HandleType
    AppendHandle

    initBufferState :: HandleType -> BufferState
    initBufferState :: HandleType -> BufferState
    initBufferState HandleType
    ReadHandle = BufferState
    ReadBuffer
    initBufferState HandleType
    _          = BufferState
    WriteBuffer

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

    openTextEncoding :: forall a.
    Maybe TextEncoding
    -> HandleType
    -> (forall es ds.
        Maybe (TextEncoder es) -> Maybe (TextDecoder ds) -> IO a)
    -> IO a
    openTextEncoding Maybe TextEncoding
    Nothing   HandleType
    ha_type forall es ds.
    Maybe (TextEncoder es) -> Maybe (TextDecoder ds) -> IO a
    cont = Maybe (TextEncoder Any) -> Maybe (TextDecoder Any) -> IO a
    forall es ds.
    Maybe (TextEncoder es) -> Maybe (TextDecoder ds) -> IO a
    cont Maybe (TextEncoder Any)
    forall a. Maybe a
    Nothing Maybe (TextDecoder Any)
    forall a. Maybe a
    Nothing
    openTextEncoding (Just TextEncoding{FilePath
    IO (TextEncoder estate)
    IO (TextDecoder dstate)
    textEncodingName :: TextEncoding -> FilePath
    mkTextEncoder :: ()
    mkTextDecoder :: ()
    mkTextEncoder :: IO (TextEncoder estate)
    mkTextDecoder :: IO (TextDecoder dstate)
    textEncodingName :: FilePath
    ..}) HandleType
    ha_type forall es ds.
    Maybe (TextEncoder es) -> Maybe (TextDecoder ds) -> IO a
    cont = do
        Maybe (TextDecoder dstate)
    mb_decoder <- if HandleType -> Bool
    isReadableHandleType HandleType
    ha_type then do
                         TextDecoder dstate
    decoder <- IO (TextDecoder dstate)
    mkTextDecoder
                         Maybe (TextDecoder dstate) -> IO (Maybe (TextDecoder dstate))
    forall (m :: * -> *) a. Monad m => a -> m a
    return (TextDecoder dstate -> Maybe (TextDecoder dstate)
    forall a. a -> Maybe a
    Just TextDecoder dstate
    decoder)
                      else
                         Maybe (TextDecoder dstate) -> IO (Maybe (TextDecoder dstate))
    forall (m :: * -> *) a. Monad m => a -> m a
    return Maybe (TextDecoder dstate)
    forall a. Maybe a
    Nothing
        Maybe (TextEncoder estate)
    mb_encoder <- if HandleType -> Bool
    isWritableHandleType HandleType
    ha_type then do
                         TextEncoder estate
    encoder <- IO (TextEncoder estate)
    mkTextEncoder
                         Maybe (TextEncoder estate) -> IO (Maybe (TextEncoder estate))
    forall (m :: * -> *) a. Monad m => a -> m a
    return (TextEncoder estate -> Maybe (TextEncoder estate)
    forall a. a -> Maybe a
    Just TextEncoder estate
    encoder)
                      else
                         Maybe (TextEncoder estate) -> IO (Maybe (TextEncoder estate))
    forall (m :: * -> *) a. Monad m => a -> m a
    return Maybe (TextEncoder estate)
    forall a. Maybe a
    Nothing
        Maybe (TextEncoder estate) -> Maybe (TextDecoder dstate) -> IO a
    forall es ds.
    Maybe (TextEncoder es) -> Maybe (TextDecoder ds) -> IO a
    cont Maybe (TextEncoder estate)
    mb_encoder Maybe (TextDecoder dstate)
    mb_decoder

    closeTextCodecs :: Handle__ -> IO ()
    closeTextCodecs :: Handle__ -> IO ()
    closeTextCodecs Handle__{dev
    Maybe (MVar Handle__)
    Maybe (TextEncoder enc_state)
    Maybe (TextDecoder dec_state)
    Maybe TextEncoding
    IORef (dec_state, Buffer Word8)
    IORef (Buffer Char)
    IORef (Buffer Word8)
    IORef (BufferList Char)
    BufferMode
    HandleType
    Newline
    haOtherSide :: Maybe (MVar Handle__)
    haOutputNL :: Newline
    haInputNL :: Newline
    haCodec :: Maybe TextEncoding
    haDecoder :: Maybe (TextDecoder dec_state)
    haEncoder :: Maybe (TextEncoder enc_state)
    haBuffers :: IORef (BufferList Char)
    haCharBuffer :: IORef (Buffer Char)
    haLastDecode :: IORef (dec_state, Buffer Word8)
    haBufferMode :: BufferMode
    haByteBuffer :: IORef (Buffer Word8)
    haType :: HandleType
    haDevice :: dev
    haType :: Handle__ -> HandleType
    haOutputNL :: Handle__ -> Newline
    haOtherSide :: Handle__ -> Maybe (MVar Handle__)
    haLastDecode :: ()
    haInputNL :: Handle__ -> Newline
    haEncoder :: ()
    haDevice :: ()
    haDecoder :: ()
    haCodec :: Handle__ -> Maybe TextEncoding
    haCharBuffer :: Handle__ -> IORef (Buffer Char)
    haByteBuffer :: Handle__ -> IORef (Buffer Word8)
    haBuffers :: Handle__ -> IORef (BufferList Char)
    haBufferMode :: Handle__ -> BufferMode
    ..} = do
      case Maybe (TextDecoder dec_state)
    haDecoder of Maybe (TextDecoder dec_state)
    Nothing -> () -> IO ()
    forall (m :: * -> *) a. Monad m => a -> m a
    return (); Just TextDecoder dec_state
    d -> TextDecoder dec_state -> IO ()
    forall from to state. BufferCodec from to state -> IO ()
    Encoding.close TextDecoder dec_state
    d
      case Maybe (TextEncoder enc_state)
    haEncoder of Maybe (TextEncoder enc_state)
    Nothing -> () -> IO ()
    forall (m :: * -> *) a. Monad m => a -> m a
    return (); Just TextEncoder enc_state
    d -> TextEncoder enc_state -> IO ()
    forall from to state. BufferCodec from to state -> IO ()
    Encoding.close TextEncoder enc_state
    d

    -- ---------------------------------------------------------------------------
    -- closing Handles

    -- hClose_help is also called by lazyRead (in GHC.IO.Handle.Text) when
    -- EOF is read or an IO error occurs on a lazy stream.  The
    -- semi-closed Handle is then closed immediately.  We have to be
    -- careful with DuplexHandles though: we have to leave the closing to
    -- the finalizer in that case, because the write side may still be in
    -- use.
    hClose_help :: Handle__ -> IO (Handle__, Maybe SomeException)
    hClose_help :: Handle__ -> IO (Handle__, Maybe SomeException)
    hClose_help Handle__
    handle_ =
      case Handle__ -> HandleType
    haType Handle__
    handle_ of
          HandleType
    ClosedHandle -> (Handle__, Maybe SomeException)
    -> IO (Handle__, Maybe SomeException)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (Handle__
    handle_,Maybe SomeException
    forall a. Maybe a
    Nothing)
          HandleType
    _ -> do Maybe SomeException
    mb_exc1 <- IO () -> IO (Maybe SomeException)
    trymaybe (IO () -> IO (Maybe SomeException))
    -> IO () -> IO (Maybe SomeException)
    forall a b. (a -> b) -> a -> b
    $ Handle__ -> IO ()
    flushWriteBuffer Handle__
    handle_ -- interruptible
                        -- it is important that hClose doesn't fail and
                        -- leave the Handle open (#3128), so we catch
                        -- exceptions when flushing the buffer.
                  (Handle__
    h_, Maybe SomeException
    mb_exc2) <- Handle__ -> IO (Handle__, Maybe SomeException)
    hClose_handle_ Handle__
    handle_
                  (Handle__, Maybe SomeException)
    -> IO (Handle__, Maybe SomeException)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (Handle__
    h_, if Maybe SomeException -> Bool
    forall a. Maybe a -> Bool
    isJust Maybe SomeException
    mb_exc1 then Maybe SomeException
    mb_exc1 else Maybe SomeException
    mb_exc2)

    trymaybe :: IO () -> IO (Maybe SomeException)
    trymaybe :: IO () -> IO (Maybe SomeException)
    trymaybe IO ()
    io = (do IO ()
    io; Maybe SomeException -> IO (Maybe SomeException)
    forall (m :: * -> *) a. Monad m => a -> m a
    return Maybe SomeException
    forall a. Maybe a
    Nothing) IO (Maybe SomeException)
    -> (SomeException -> IO (Maybe SomeException))
    -> IO (Maybe SomeException)
    forall e a. Exception e => IO a -> (e -> IO a) -> IO a
    `catchException` \SomeException
    e -> Maybe SomeException -> IO (Maybe SomeException)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (SomeException -> Maybe SomeException
    forall a. a -> Maybe a
    Just SomeException
    e)

    hClose_handle_ :: Handle__ -> IO (Handle__, Maybe SomeException)
    hClose_handle_ :: Handle__ -> IO (Handle__, Maybe SomeException)
    hClose_handle_ h_ :: Handle__
    h_@Handle__{dev
    Maybe (MVar Handle__)
    Maybe (TextEncoder enc_state)
    Maybe (TextDecoder dec_state)
    Maybe TextEncoding
    IORef (dec_state, Buffer Word8)
    IORef (Buffer Char)
    IORef (Buffer Word8)
    IORef (BufferList Char)
    BufferMode
    HandleType
    Newline
    haOtherSide :: Maybe (MVar Handle__)
    haOutputNL :: Newline
    haInputNL :: Newline
    haCodec :: Maybe TextEncoding
    haDecoder :: Maybe (TextDecoder dec_state)
    haEncoder :: Maybe (TextEncoder enc_state)
    haBuffers :: IORef (BufferList Char)
    haCharBuffer :: IORef (Buffer Char)
    haLastDecode :: IORef (dec_state, Buffer Word8)
    haBufferMode :: BufferMode
    haByteBuffer :: IORef (Buffer Word8)
    haType :: HandleType
    haDevice :: dev
    haType :: Handle__ -> HandleType
    haOutputNL :: Handle__ -> Newline
    haOtherSide :: Handle__ -> Maybe (MVar Handle__)
    haLastDecode :: ()
    haInputNL :: Handle__ -> Newline
    haEncoder :: ()
    haDevice :: ()
    haDecoder :: ()
    haCodec :: Handle__ -> Maybe TextEncoding
    haCharBuffer :: Handle__ -> IORef (Buffer Char)
    haByteBuffer :: Handle__ -> IORef (Buffer Word8)
    haBuffers :: Handle__ -> IORef (BufferList Char)
    haBufferMode :: Handle__ -> BufferMode
    ..} = do

        -- close the file descriptor, but not when this is the read
        -- side of a duplex handle.
        -- If an exception is raised by the close(), we want to continue
        -- to close the handle and release the lock if it has one, then
        -- we return the exception to the caller of hClose_help which can
        -- raise it if necessary.
        Maybe SomeException
    maybe_exception <-
          case Maybe (MVar Handle__)
    haOtherSide of
            Maybe (MVar Handle__)
    Nothing -> IO () -> IO (Maybe SomeException)
    trymaybe (IO () -> IO (Maybe SomeException))
    -> IO () -> IO (Maybe SomeException)
    forall a b. (a -> b) -> a -> b
    $ dev -> IO ()
    forall a. IODevice a => a -> IO ()
    IODevice.close dev
    haDevice
            Just MVar Handle__
    _  -> Maybe SomeException -> IO (Maybe SomeException)
    forall (m :: * -> *) a. Monad m => a -> m a
    return Maybe SomeException
    forall a. Maybe a
    Nothing

        -- free the spare buffers
        IORef (BufferList Char) -> BufferList Char -> IO ()
    forall a. IORef a -> a -> IO ()
    writeIORef IORef (BufferList Char)
    haBuffers BufferList Char
    forall e. BufferList e
    BufferListNil
        IORef (Buffer Char) -> Buffer Char -> IO ()
    forall a. IORef a -> a -> IO ()
    writeIORef IORef (Buffer Char)
    haCharBuffer Buffer Char
    noCharBuffer
        IORef (Buffer Word8) -> Buffer Word8 -> IO ()
    forall a. IORef a -> a -> IO ()
    writeIORef IORef (Buffer Word8)
    haByteBuffer Buffer Word8
    noByteBuffer

        -- release our encoder/decoder
        Handle__ -> IO ()
    closeTextCodecs Handle__
    h_

        -- we must set the fd to -1, because the finalizer is going
        -- to run eventually and try to close/unlock it.
        -- ToDo: necessary?  the handle will be marked ClosedHandle
        -- XXX GHC won't let us use record update here, hence wildcards
        (Handle__, Maybe SomeException)
    -> IO (Handle__, Maybe SomeException)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (Handle__ :: forall dev enc_state dec_state.
    (RawIO dev, IODevice dev, BufferedIO dev, Typeable dev) =>
    dev
    -> HandleType
    -> IORef (Buffer Word8)
    -> BufferMode
    -> IORef (dec_state, Buffer Word8)
    -> IORef (Buffer Char)
    -> IORef (BufferList Char)
    -> Maybe (TextEncoder enc_state)
    -> Maybe (TextDecoder dec_state)
    -> Maybe TextEncoding
    -> Newline
    -> Newline
    -> Maybe (MVar Handle__)
    -> Handle__
    Handle__{ haType :: HandleType
    haType = HandleType
    ClosedHandle, dev
    Maybe (MVar Handle__)
    Maybe (TextEncoder enc_state)
    Maybe (TextDecoder dec_state)
    Maybe TextEncoding
    IORef (dec_state, Buffer Word8)
    IORef (Buffer Char)
    IORef (Buffer Word8)
    IORef (BufferList Char)
    BufferMode
    Newline
    haOtherSide :: Maybe (MVar Handle__)
    haOutputNL :: Newline
    haInputNL :: Newline
    haCodec :: Maybe TextEncoding
    haDecoder :: Maybe (TextDecoder dec_state)
    haEncoder :: Maybe (TextEncoder enc_state)
    haBuffers :: IORef (BufferList Char)
    haCharBuffer :: IORef (Buffer Char)
    haLastDecode :: IORef (dec_state, Buffer Word8)
    haBufferMode :: BufferMode
    haByteBuffer :: IORef (Buffer Word8)
    haDevice :: dev
    haOutputNL :: Newline
    haOtherSide :: Maybe (MVar Handle__)
    haLastDecode :: IORef (dec_state, Buffer Word8)
    haInputNL :: Newline
    haEncoder :: Maybe (TextEncoder enc_state)
    haDevice :: dev
    haDecoder :: Maybe (TextDecoder dec_state)
    haCodec :: Maybe TextEncoding
    haCharBuffer :: IORef (Buffer Char)
    haByteBuffer :: IORef (Buffer Word8)
    haBuffers :: IORef (BufferList Char)
    haBufferMode :: BufferMode
    .. }, Maybe SomeException
    maybe_exception)

    {-# NOINLINE noCharBuffer #-}
    noCharBuffer :: CharBuffer
    noCharBuffer :: Buffer Char
    noCharBuffer = IO (Buffer Char) -> Buffer Char
    forall a. IO a -> a
    unsafePerformIO (IO (Buffer Char) -> Buffer Char)
    -> IO (Buffer Char) -> Buffer Char
    forall a b. (a -> b) -> a -> b
    $ Int -> BufferState -> IO (Buffer Char)
    newCharBuffer Int
    1 BufferState
    ReadBuffer

    {-# NOINLINE noByteBuffer #-}
    noByteBuffer :: Buffer Word8
    noByteBuffer :: Buffer Word8
    noByteBuffer = IO (Buffer Word8) -> Buffer Word8
    forall a. IO a -> a
    unsafePerformIO (IO (Buffer Word8) -> Buffer Word8)
    -> IO (Buffer Word8) -> Buffer Word8
    forall a b. (a -> b) -> a -> b
    $ Int -> BufferState -> IO (Buffer Word8)
    newByteBuffer Int
    1 BufferState
    ReadBuffer

    -- ---------------------------------------------------------------------------
    -- Looking ahead

    hLookAhead_ :: Handle__ -> IO Char
    hLookAhead_ :: Handle__ -> IO Char
    hLookAhead_ handle_ :: Handle__
    handle_@Handle__{dev
    Maybe (MVar Handle__)
    Maybe (TextEncoder enc_state)
    Maybe (TextDecoder dec_state)
    Maybe TextEncoding
    IORef (dec_state, Buffer Word8)
    IORef (Buffer Char)
    IORef (Buffer Word8)
    IORef (BufferList Char)
    BufferMode
    HandleType
    Newline
    haOtherSide :: Maybe (MVar Handle__)
    haOutputNL :: Newline
    haInputNL :: Newline
    haCodec :: Maybe TextEncoding
    haDecoder :: Maybe (TextDecoder dec_state)
    haEncoder :: Maybe (TextEncoder enc_state)
    haBuffers :: IORef (BufferList Char)
    haCharBuffer :: IORef (Buffer Char)
    haLastDecode :: IORef (dec_state, Buffer Word8)
    haBufferMode :: BufferMode
    haByteBuffer :: IORef (Buffer Word8)
    haType :: HandleType
    haDevice :: dev
    haType :: Handle__ -> HandleType
    haOutputNL :: Handle__ -> Newline
    haOtherSide :: Handle__ -> Maybe (MVar Handle__)
    haLastDecode :: ()
    haInputNL :: Handle__ -> Newline
    haEncoder :: ()
    haDevice :: ()
    haDecoder :: ()
    haCodec :: Handle__ -> Maybe TextEncoding
    haCharBuffer :: Handle__ -> IORef (Buffer Char)
    haByteBuffer :: Handle__ -> IORef (Buffer Word8)
    haBuffers :: Handle__ -> IORef (BufferList Char)
    haBufferMode :: Handle__ -> BufferMode
    ..} = do
        Buffer Char
    buf <- IORef (Buffer Char) -> IO (Buffer Char)
    forall a. IORef a -> IO a
    readIORef IORef (Buffer Char)
    haCharBuffer

        -- fill up the read buffer if necessary
        Buffer Char
    new_buf <- if Buffer Char -> Bool
    forall e. Buffer e -> Bool
    isEmptyBuffer Buffer Char
    buf
                      then Handle__ -> Buffer Char -> IO (Buffer Char)
    readTextDevice Handle__
    handle_ Buffer Char
    buf
                      else Buffer Char -> IO (Buffer Char)
    forall (m :: * -> *) a. Monad m => a -> m a
    return Buffer Char
    buf
        IORef (Buffer Char) -> Buffer Char -> IO ()
    forall a. IORef a -> a -> IO ()
    writeIORef IORef (Buffer Char)
    haCharBuffer Buffer Char
    new_buf

        RawCharBuffer -> Int -> IO Char
    peekCharBuf (Buffer Char -> RawCharBuffer
    forall e. Buffer e -> RawBuffer e
    bufRaw Buffer Char
    buf) (Buffer Char -> Int
    forall e. Buffer e -> Int
    bufL Buffer Char
    buf)

    -- ---------------------------------------------------------------------------
    -- debugging

    debugIO :: String -> IO ()
    -- debugIO s = traceEventIO s
    debugIO :: FilePath -> IO ()
    debugIO FilePath
    s
     | Bool
    c_DEBUG_DUMP
        = do CSsize
    _ <- FilePath -> (CStringLen -> IO CSsize) -> IO CSsize
    forall a. FilePath -> (CStringLen -> IO a) -> IO a
    withCStringLen (FilePath
    s FilePath -> FilePath -> FilePath
    forall a. [a] -> [a] -> [a]
    ++ FilePath
    "\n") ((CStringLen -> IO CSsize) -> IO CSsize)
    -> (CStringLen -> IO CSsize) -> IO CSsize
    forall a b. (a -> b) -> a -> b
    $
                      \(Ptr CChar
    p, Int
    len) -> CInt -> Ptr Word8 -> CSize -> IO CSsize
    c_write CInt
    1 (Ptr CChar -> Ptr Word8
    forall a b. Ptr a -> Ptr b
    castPtr Ptr CChar
    p) (Int -> CSize
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral Int
    len)
             () -> IO ()
    forall (m :: * -> *) a. Monad m => a -> m a
    return ()
     | Bool
    otherwise = () -> IO ()
    forall (m :: * -> *) a. Monad m => a -> m a
    return ()

    -- For development, like debugIO but always on.
    traceIO :: String -> IO ()
    traceIO :: FilePath -> IO ()
    traceIO FilePath
    s = do
             CSsize
    _ <- FilePath -> (CStringLen -> IO CSsize) -> IO CSsize
    forall a. FilePath -> (CStringLen -> IO a) -> IO a
    withCStringLen (FilePath
    s FilePath -> FilePath -> FilePath
    forall a. [a] -> [a] -> [a]
    ++ FilePath
    "\n") ((CStringLen -> IO CSsize) -> IO CSsize)
    -> (CStringLen -> IO CSsize) -> IO CSsize
    forall a b. (a -> b) -> a -> b
    $
                      \(Ptr CChar
    p, Int
    len) -> CInt -> Ptr Word8 -> CSize -> IO CSsize
    c_write CInt
    1 (Ptr CChar -> Ptr Word8
    forall a b. Ptr a -> Ptr b
    castPtr Ptr CChar
    p) (Int -> CSize
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral Int
    len)
             () -> IO ()
    forall (m :: * -> *) a. Monad m => a -> m a
    return ()

    -- ----------------------------------------------------------------------------
    -- Text input/output

    -- Read characters into the provided buffer.  Return when any
    -- characters are available; raise an exception if the end of
    -- file is reached.
    --
    -- In uses of readTextDevice within base, the input buffer is either:
    --   * empty
    --   * or contains a single \r (when doing newline translation)
    --
    -- The input character buffer must have a capacity at least 1 greater
    -- than the number of elements it currently contains.
    --
    -- Users of this function expect that the buffer returned contains
    -- at least 1 more character than the input buffer.
    readTextDevice :: Handle__ -> CharBuffer -> IO CharBuffer
    readTextDevice :: Handle__ -> Buffer Char -> IO (Buffer Char)
    readTextDevice h_ :: Handle__
    h_@Handle__{dev
    Maybe (MVar Handle__)
    Maybe (TextEncoder enc_state)
    Maybe (TextDecoder dec_state)
    Maybe TextEncoding
    IORef (dec_state, Buffer Word8)
    IORef (Buffer Char)
    IORef (Buffer Word8)
    IORef (BufferList Char)
    BufferMode
    HandleType
    Newline
    haOtherSide :: Maybe (MVar Handle__)
    haOutputNL :: Newline
    haInputNL :: Newline
    haCodec :: Maybe TextEncoding
    haDecoder :: Maybe (TextDecoder dec_state)
    haEncoder :: Maybe (TextEncoder enc_state)
    haBuffers :: IORef (BufferList Char)
    haCharBuffer :: IORef (Buffer Char)
    haLastDecode :: IORef (dec_state, Buffer Word8)
    haBufferMode :: BufferMode
    haByteBuffer :: IORef (Buffer Word8)
    haType :: HandleType
    haDevice :: dev
    haType :: Handle__ -> HandleType
    haOutputNL :: Handle__ -> Newline
    haOtherSide :: Handle__ -> Maybe (MVar Handle__)
    haLastDecode :: ()
    haInputNL :: Handle__ -> Newline
    haEncoder :: ()
    haDevice :: ()
    haDecoder :: ()
    haCodec :: Handle__ -> Maybe TextEncoding
    haCharBuffer :: Handle__ -> IORef (Buffer Char)
    haByteBuffer :: Handle__ -> IORef (Buffer Word8)
    haBuffers :: Handle__ -> IORef (BufferList Char)
    haBufferMode :: Handle__ -> BufferMode
    ..} Buffer Char
    cbuf = do
      --
      Buffer Word8
    bbuf0 <- IORef (Buffer Word8) -> IO (Buffer Word8)
    forall a. IORef a -> IO a
    readIORef IORef (Buffer Word8)
    haByteBuffer

      FilePath -> IO ()
    debugIO (FilePath
    "readTextDevice: cbuf=" FilePath -> FilePath -> FilePath
    forall a. [a] -> [a] -> [a]
    ++ Buffer Char -> FilePath
    forall a. Buffer a -> FilePath
    summaryBuffer Buffer Char
    cbuf FilePath -> FilePath -> FilePath
    forall a. [a] -> [a] -> [a]
    ++
            FilePath
    " bbuf=" FilePath -> FilePath -> FilePath
    forall a. [a] -> [a] -> [a]
    ++ Buffer Word8 -> FilePath
    forall a. Buffer a -> FilePath
    summaryBuffer Buffer Word8
    bbuf0)

      Buffer Word8
    bbuf1 <- if Bool -> Bool
    not (Buffer Word8 -> Bool
    forall e. Buffer e -> Bool
    isEmptyBuffer Buffer Word8
    bbuf0)
                  then Buffer Word8 -> IO (Buffer Word8)
    forall (m :: * -> *) a. Monad m => a -> m a
    return Buffer Word8
    bbuf0
                  else do
                       FilePath -> IO ()
    debugIO (FilePath -> IO ()) -> FilePath -> IO ()
    forall a b. (a -> b) -> a -> b
    $ FilePath
    "readBuf at " FilePath -> FilePath -> FilePath
    forall a. [a] -> [a] -> [a]
    ++ Word64 -> FilePath
    forall a. Show a => a -> FilePath
    show (Buffer Word8 -> Word64
    forall e. Buffer e -> Word64
    bufferOffset Buffer Word8
    bbuf0)
                       (Int
    r,Buffer Word8
    bbuf1) <- dev -> Buffer Word8 -> IO (Int, Buffer Word8)
    forall dev.
    BufferedIO dev =>
    dev -> Buffer Word8 -> IO (Int, Buffer Word8)
    Buffered.fillReadBuffer dev
    haDevice Buffer Word8
    bbuf0
                       FilePath -> IO ()
    debugIO (FilePath -> IO ()) -> FilePath -> IO ()
    forall a b. (a -> b) -> a -> b
    $ FilePath
    "readBuf after " FilePath -> FilePath -> FilePath
    forall a. [a] -> [a] -> [a]
    ++ Word64 -> FilePath
    forall a. Show a => a -> FilePath
    show (Buffer Word8 -> Word64
    forall e. Buffer e -> Word64
    bufferOffset Buffer Word8
    bbuf1)
                       if Int
    r Int -> Int -> Bool
    forall a. Eq a => a -> a -> Bool
    == Int
    0 then IO (Buffer Word8)
    forall a. IO a
    ioe_EOF else do  -- raise EOF
                       Buffer Word8 -> IO (Buffer Word8)
    forall (m :: * -> *) a. Monad m => a -> m a
    return Buffer Word8
    bbuf1

      FilePath -> IO ()
    debugIO (FilePath
    "readTextDevice after reading: bbuf=" FilePath -> FilePath -> FilePath
    forall a. [a] -> [a] -> [a]
    ++ Buffer Word8 -> FilePath
    forall a. Buffer a -> FilePath
    summaryBuffer Buffer Word8
    bbuf1)

      (Buffer Word8
    bbuf2,Buffer Char
    cbuf') <-
          case Maybe (TextDecoder dec_state)
    haDecoder of
              Maybe (TextDecoder dec_state)
    Nothing      -> do
                   IORef (dec_state, Buffer Word8)
    -> (dec_state, Buffer Word8) -> IO ()
    forall a. IORef a -> a -> IO ()
    writeIORef IORef (dec_state, Buffer Word8)
    haLastDecode (FilePath -> dec_state
    forall a. FilePath -> a
    errorWithoutStackTrace FilePath
    "codec_state", Buffer Word8
    bbuf1)
                   Buffer Word8 -> Buffer Char -> IO (Buffer Word8, Buffer Char)
    latin1_decode Buffer Word8
    bbuf1 Buffer Char
    cbuf
              Just TextDecoder dec_state
    decoder -> do
                   dec_state
    state <- TextDecoder dec_state -> IO dec_state
    forall from to state. BufferCodec from to state -> IO state
    getState TextDecoder dec_state
    decoder
                   IORef (dec_state, Buffer Word8)
    -> (dec_state, Buffer Word8) -> IO ()
    forall a. IORef a -> a -> IO ()
    writeIORef IORef (dec_state, Buffer Word8)
    haLastDecode (dec_state
    state, Buffer Word8
    bbuf1)
                   (TextDecoder dec_state
    -> Buffer Word8 -> Buffer Char -> IO (Buffer Word8, Buffer Char)
    forall from to state.
    BufferCodec from to state
    -> Buffer from -> Buffer to -> IO (Buffer from, Buffer to)
    streamEncode TextDecoder dec_state
    decoder) Buffer Word8
    bbuf1 Buffer Char
    cbuf

      FilePath -> IO ()
    debugIO (FilePath
    "readTextDevice after decoding: cbuf=" FilePath -> FilePath -> FilePath
    forall a. [a] -> [a] -> [a]
    ++ Buffer Char -> FilePath
    forall a. Buffer a -> FilePath
    summaryBuffer Buffer Char
    cbuf' FilePath -> FilePath -> FilePath
    forall a. [a] -> [a] -> [a]
    ++
            FilePath
    " bbuf=" FilePath -> FilePath -> FilePath
    forall a. [a] -> [a] -> [a]
    ++ Buffer Word8 -> FilePath
    forall a. Buffer a -> FilePath
    summaryBuffer Buffer Word8
    bbuf2)

      -- We can't return from readTextDevice without reading at least a single extra character,
      -- so check that we have managed to achieve that
      IORef (Buffer Word8) -> Buffer Word8 -> IO ()
    forall a. IORef a -> a -> IO ()
    writeIORef IORef (Buffer Word8)
    haByteBuffer Buffer Word8
    bbuf2
      if Buffer Char -> Int
    forall e. Buffer e -> Int
    bufR Buffer Char
    cbuf' Int -> Int -> Bool
    forall a. Eq a => a -> a -> Bool
    == Buffer Char -> Int
    forall e. Buffer e -> Int
    bufR Buffer Char
    cbuf
         -- we need more bytes to make a Char. NB: bbuf2 may be empty (even though bbuf1 wasn't) when we
         -- are using an encoding that can skip bytes without outputting characters, such as UTF8//IGNORE
         then Handle__ -> Buffer Word8 -> Buffer Char -> IO (Buffer Char)
    readTextDevice' Handle__
    h_ Buffer Word8
    bbuf2 Buffer Char
    cbuf
         else Buffer Char -> IO (Buffer Char)
    forall (m :: * -> *) a. Monad m => a -> m a
    return Buffer Char
    cbuf'

    -- we have an incomplete byte sequence at the end of the buffer: try to
    -- read more bytes.
    readTextDevice' :: Handle__ -> Buffer Word8 -> CharBuffer -> IO CharBuffer
    readTextDevice' :: Handle__ -> Buffer Word8 -> Buffer Char -> IO (Buffer Char)
    readTextDevice' h_ :: Handle__
    h_@Handle__{dev
    Maybe (MVar Handle__)
    Maybe (TextEncoder enc_state)
    Maybe (TextDecoder dec_state)
    Maybe TextEncoding
    IORef (dec_state, Buffer Word8)
    IORef (Buffer Char)
    IORef (Buffer Word8)
    IORef (BufferList Char)
    BufferMode
    HandleType
    Newline
    haOtherSide :: Maybe (MVar Handle__)
    haOutputNL :: Newline
    haInputNL :: Newline
    haCodec :: Maybe TextEncoding
    haDecoder :: Maybe (TextDecoder dec_state)
    haEncoder :: Maybe (TextEncoder enc_state)
    haBuffers :: IORef (BufferList Char)
    haCharBuffer :: IORef (Buffer Char)
    haLastDecode :: IORef (dec_state, Buffer Word8)
    haBufferMode :: BufferMode
    haByteBuffer :: IORef (Buffer Word8)
    haType :: HandleType
    haDevice :: dev
    haType :: Handle__ -> HandleType
    haOutputNL :: Handle__ -> Newline
    haOtherSide :: Handle__ -> Maybe (MVar Handle__)
    haLastDecode :: ()
    haInputNL :: Handle__ -> Newline
    haEncoder :: ()
    haDevice :: ()
    haDecoder :: ()
    haCodec :: Handle__ -> Maybe TextEncoding
    haCharBuffer :: Handle__ -> IORef (Buffer Char)
    haByteBuffer :: Handle__ -> IORef (Buffer Word8)
    haBuffers :: Handle__ -> IORef (BufferList Char)
    haBufferMode :: Handle__ -> BufferMode
    ..} Buffer Word8
    bbuf0 Buffer Char
    cbuf0 = do
      --
      -- copy the partial sequence to the beginning of the buffer, so we have
      -- room to read more bytes.
      Buffer Word8
    bbuf1 <- Buffer Word8 -> IO (Buffer Word8)
    slideContents Buffer Word8
    bbuf0

      -- readTextDevice only calls us if we got some bytes but not some characters.
      -- This can't occur if haDecoder is Nothing because latin1_decode accepts all bytes.
      let Just TextDecoder dec_state
    decoder = Maybe (TextDecoder dec_state)
    haDecoder

      (Int
    r,Buffer Word8
    bbuf2) <- dev -> Buffer Word8 -> IO (Int, Buffer Word8)
    forall dev.
    BufferedIO dev =>
    dev -> Buffer Word8 -> IO (Int, Buffer Word8)
    Buffered.fillReadBuffer dev
    haDevice Buffer Word8
    bbuf1
      if Int
    r Int -> Int -> Bool
    forall a. Eq a => a -> a -> Bool
    == Int
    0
       then do
         -- bbuf2 can be empty here when we encounter an invalid byte sequence at the end of the input
         -- with a //IGNORE codec which consumes bytes without outputting characters
         if Buffer Word8 -> Bool
    forall e. Buffer e -> Bool
    isEmptyBuffer Buffer Word8
    bbuf2 then IO (Buffer Char)
    forall a. IO a
    ioe_EOF else do
         (Buffer Word8
    bbuf3, Buffer Char
    cbuf1) <- TextDecoder dec_state
    -> Buffer Word8 -> Buffer Char -> IO (Buffer Word8, Buffer Char)
    forall from to state.
    BufferCodec from to state
    -> Buffer from -> Buffer to -> IO (Buffer from, Buffer to)
    recover TextDecoder dec_state
    decoder Buffer Word8
    bbuf2 Buffer Char
    cbuf0
         FilePath -> IO ()
    debugIO (FilePath
    "readTextDevice' after recovery: bbuf=" FilePath -> FilePath -> FilePath
    forall a. [a] -> [a] -> [a]
    ++ Buffer Word8 -> FilePath
    forall a. Buffer a -> FilePath
    summaryBuffer Buffer Word8
    bbuf3 FilePath -> FilePath -> FilePath
    forall a. [a] -> [a] -> [a]
    ++ FilePath
    ", cbuf=" FilePath -> FilePath -> FilePath
    forall a. [a] -> [a] -> [a]
    ++ Buffer Char -> FilePath
    forall a. Buffer a -> FilePath
    summaryBuffer Buffer Char
    cbuf1)
         IORef (Buffer Word8) -> Buffer Word8 -> IO ()
    forall a. IORef a -> a -> IO ()
    writeIORef IORef (Buffer Word8)
    haByteBuffer Buffer Word8
    bbuf3
         -- We should recursively invoke readTextDevice after recovery,
         -- if recovery did not add at least one new character to the buffer:
         --  1. If we were using IgnoreCodingFailure it might be the case that
         --     cbuf1 is the same length as cbuf0 and we need to raise ioe_EOF
         --  2. If we were using TransliterateCodingFailure we might have *mutated*
         --     the byte buffer without changing the pointers into either buffer.
         --     We need to try and decode it again - it might just go through this time.
         if Buffer Char -> Int
    forall e. Buffer e -> Int
    bufR Buffer Char
    cbuf1 Int -> Int -> Bool
    forall a. Eq a => a -> a -> Bool
    == Buffer Char -> Int
    forall e. Buffer e -> Int
    bufR Buffer Char
    cbuf0
          then Handle__ -> Buffer Char -> IO (Buffer Char)
    readTextDevice Handle__
    h_ Buffer Char
    cbuf1
          else Buffer Char -> IO (Buffer Char)
    forall (m :: * -> *) a. Monad m => a -> m a
    return Buffer Char
    cbuf1
       else do
        FilePath -> IO ()
    debugIO (FilePath
    "readTextDevice' after reading: bbuf=" FilePath -> FilePath -> FilePath
    forall a. [a] -> [a] -> [a]
    ++ Buffer Word8 -> FilePath
    forall a. Buffer a -> FilePath
    summaryBuffer Buffer Word8
    bbuf2)

        (Buffer Word8
    bbuf3,Buffer Char
    cbuf1) <- do
           dec_state
    state <- TextDecoder dec_state -> IO dec_state
    forall from to state. BufferCodec from to state -> IO state
    getState TextDecoder dec_state
    decoder
           IORef (dec_state, Buffer Word8)
    -> (dec_state, Buffer Word8) -> IO ()
    forall a. IORef a -> a -> IO ()
    writeIORef IORef (dec_state, Buffer Word8)
    haLastDecode (dec_state
    state, Buffer Word8
    bbuf2)
           (TextDecoder dec_state
    -> Buffer Word8 -> Buffer Char -> IO (Buffer Word8, Buffer Char)
    forall from to state.
    BufferCodec from to state
    -> Buffer from -> Buffer to -> IO (Buffer from, Buffer to)
    streamEncode TextDecoder dec_state
    decoder) Buffer Word8
    bbuf2 Buffer Char
    cbuf0

        FilePath -> IO ()
    debugIO (FilePath
    "readTextDevice' after decoding: cbuf=" FilePath -> FilePath -> FilePath
    forall a. [a] -> [a] -> [a]
    ++ Buffer Char -> FilePath
    forall a. Buffer a -> FilePath
    summaryBuffer Buffer Char
    cbuf1 FilePath -> FilePath -> FilePath
    forall a. [a] -> [a] -> [a]
    ++
              FilePath
    " bbuf=" FilePath -> FilePath -> FilePath
    forall a. [a] -> [a] -> [a]
    ++ Buffer Word8 -> FilePath
    forall a. Buffer a -> FilePath
    summaryBuffer Buffer Word8
    bbuf3)

        IORef (Buffer Word8) -> Buffer Word8 -> IO ()
    forall a. IORef a -> a -> IO ()
    writeIORef IORef (Buffer Word8)
    haByteBuffer Buffer Word8
    bbuf3
        if Buffer Char -> Int
    forall e. Buffer e -> Int
    bufR Buffer Char
    cbuf0 Int -> Int -> Bool
    forall a. Eq a => a -> a -> Bool
    == Buffer Char -> Int
    forall e. Buffer e -> Int
    bufR Buffer Char
    cbuf1
           then Handle__ -> Buffer Word8 -> Buffer Char -> IO (Buffer Char)
    readTextDevice' Handle__
    h_ Buffer Word8
    bbuf3 Buffer Char
    cbuf1
           else Buffer Char -> IO (Buffer Char)
    forall (m :: * -> *) a. Monad m => a -> m a
    return Buffer Char
    cbuf1

    -- Read characters into the provided buffer.  Do not block;
    -- return zero characters instead.  Raises an exception on end-of-file.
    readTextDeviceNonBlocking :: Handle__ -> CharBuffer -> IO CharBuffer
    readTextDeviceNonBlocking :: Handle__ -> Buffer Char -> IO (Buffer Char)
    readTextDeviceNonBlocking h_ :: Handle__
    h_@Handle__{dev
    Maybe (MVar Handle__)
    Maybe (TextEncoder enc_state)
    Maybe (TextDecoder dec_state)
    Maybe TextEncoding
    IORef (dec_state, Buffer Word8)
    IORef (Buffer Char)
    IORef (Buffer Word8)
    IORef (BufferList Char)
    BufferMode
    HandleType
    Newline
    haOtherSide :: Maybe (MVar Handle__)
    haOutputNL :: Newline
    haInputNL :: Newline
    haCodec :: Maybe TextEncoding
    haDecoder :: Maybe (TextDecoder dec_state)
    haEncoder :: Maybe (TextEncoder enc_state)
    haBuffers :: IORef (BufferList Char)
    haCharBuffer :: IORef (Buffer Char)
    haLastDecode :: IORef (dec_state, Buffer Word8)
    haBufferMode :: BufferMode
    haByteBuffer :: IORef (Buffer Word8)
    haType :: HandleType
    haDevice :: dev
    haType :: Handle__ -> HandleType
    haOutputNL :: Handle__ -> Newline
    haOtherSide :: Handle__ -> Maybe (MVar Handle__)
    haLastDecode :: ()
    haInputNL :: Handle__ -> Newline
    haEncoder :: ()
    haDevice :: ()
    haDecoder :: ()
    haCodec :: Handle__ -> Maybe TextEncoding
    haCharBuffer :: Handle__ -> IORef (Buffer Char)
    haByteBuffer :: Handle__ -> IORef (Buffer Word8)
    haBuffers :: Handle__ -> IORef (BufferList Char)
    haBufferMode :: Handle__ -> BufferMode
    ..} Buffer Char
    cbuf = do
      --
      Buffer Word8
    bbuf0 <- IORef (Buffer Word8) -> IO (Buffer Word8)
    forall a. IORef a -> IO a
    readIORef IORef (Buffer Word8)
    haByteBuffer
      Bool -> IO () -> IO ()
    forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
    when (Buffer Word8 -> Bool
    forall e. Buffer e -> Bool
    isEmptyBuffer Buffer Word8
    bbuf0) (IO () -> IO ()) -> IO () -> IO ()
    forall a b. (a -> b) -> a -> b
    $ do
         (Maybe Int
    r,Buffer Word8
    bbuf1) <- dev -> Buffer Word8 -> IO (Maybe Int, Buffer Word8)
    forall dev.
    BufferedIO dev =>
    dev -> Buffer Word8 -> IO (Maybe Int, Buffer Word8)
    Buffered.fillReadBuffer0 dev
    haDevice Buffer Word8
    bbuf0
         if Maybe Int -> Bool
    forall a. Maybe a -> Bool
    isNothing Maybe Int
    r then IO ()
    forall a. IO a
    ioe_EOF else do  -- raise EOF
         IORef (Buffer Word8) -> Buffer Word8 -> IO ()
    forall a. IORef a -> a -> IO ()
    writeIORef IORef (Buffer Word8)
    haByteBuffer Buffer Word8
    bbuf1

      Handle__ -> Buffer Char -> IO (Buffer Char)
    decodeByteBuf Handle__
    h_ Buffer Char
    cbuf

    -- Decode bytes from the byte buffer into the supplied CharBuffer.
    decodeByteBuf :: Handle__ -> CharBuffer -> IO CharBuffer
    decodeByteBuf :: Handle__ -> Buffer Char -> IO (Buffer Char)
    decodeByteBuf h_ :: Handle__
    h_@Handle__{dev
    Maybe (MVar Handle__)
    Maybe (TextEncoder enc_state)
    Maybe (TextDecoder dec_state)
    Maybe TextEncoding
    IORef (dec_state, Buffer Word8)
    IORef (Buffer Char)
    IORef (Buffer Word8)
    IORef (BufferList Char)
    BufferMode
    HandleType
    Newline
    haOtherSide :: Maybe (MVar Handle__)
    haOutputNL :: Newline
    haInputNL :: Newline
    haCodec :: Maybe TextEncoding
    haDecoder :: Maybe (TextDecoder dec_state)
    haEncoder :: Maybe (TextEncoder enc_state)
    haBuffers :: IORef (BufferList Char)
    haCharBuffer :: IORef (Buffer Char)
    haLastDecode :: IORef (dec_state, Buffer Word8)
    haBufferMode :: BufferMode
    haByteBuffer :: IORef (Buffer Word8)
    haType :: HandleType
    haDevice :: dev
    haType :: Handle__ -> HandleType
    haOutputNL :: Handle__ -> Newline
    haOtherSide :: Handle__ -> Maybe (MVar Handle__)
    haLastDecode :: ()
    haInputNL :: Handle__ -> Newline
    haEncoder :: ()
    haDevice :: ()
    haDecoder :: ()
    haCodec :: Handle__ -> Maybe TextEncoding
    haCharBuffer :: Handle__ -> IORef (Buffer Char)
    haByteBuffer :: Handle__ -> IORef (Buffer Word8)
    haBuffers :: Handle__ -> IORef (BufferList Char)
    haBufferMode :: Handle__ -> BufferMode
    ..} Buffer Char
    cbuf = do
      --
      Buffer Word8
    bbuf0 <- IORef (Buffer Word8) -> IO (Buffer Word8)
    forall a. IORef a -> IO a
    readIORef IORef (Buffer Word8)
    haByteBuffer

      (Buffer Word8
    bbuf2,Buffer Char
    cbuf') <-
          case Maybe (TextDecoder dec_state)
    haDecoder of
              Maybe (TextDecoder dec_state)
    Nothing      -> do
                   IORef (dec_state, Buffer Word8)
    -> (dec_state, Buffer Word8) -> IO ()
    forall a. IORef a -> a -> IO ()
    writeIORef IORef (dec_state, Buffer Word8)
    haLastDecode (FilePath -> dec_state
    forall a. FilePath -> a
    errorWithoutStackTrace FilePath
    "codec_state", Buffer Word8
    bbuf0)
                   Buffer Word8 -> Buffer Char -> IO (Buffer Word8, Buffer Char)
    latin1_decode Buffer Word8
    bbuf0 Buffer Char
    cbuf
              Just TextDecoder dec_state
    decoder -> do
                   dec_state
    state <- TextDecoder dec_state -> IO dec_state
    forall from to state. BufferCodec from to state -> IO state
    getState TextDecoder dec_state
    decoder
                   IORef (dec_state, Buffer Word8)
    -> (dec_state, Buffer Word8) -> IO ()
    forall a. IORef a -> a -> IO ()
    writeIORef IORef (dec_state, Buffer Word8)
    haLastDecode (dec_state
    state, Buffer Word8
    bbuf0)
                   (TextDecoder dec_state
    -> Buffer Word8 -> Buffer Char -> IO (Buffer Word8, Buffer Char)
    forall from to state.
    BufferCodec from to state
    -> Buffer from -> Buffer to -> IO (Buffer from, Buffer to)
    streamEncode TextDecoder dec_state
    decoder) Buffer Word8
    bbuf0 Buffer Char
    cbuf

      IORef (Buffer Word8) -> Buffer Word8 -> IO ()
    forall a. IORef a -> a -> IO ()
    writeIORef IORef (Buffer Word8)
    haByteBuffer Buffer Word8
    bbuf2
      Buffer Char -> IO (Buffer Char)
    forall (m :: * -> *) a. Monad m => a -> m a
    return Buffer Char
    cbuf'