{-# LANGUAGE Trustworthy #-}
{-# LANGUAGE CPP, NoImplicitPrelude #-}
{-# LANGUAGE UnboxedTuples #-}
{-# OPTIONS_GHC -funbox-strict-fields #-}

-----------------------------------------------------------------------------
-- |
-- Module      :  GHC.Internal.IO.Encoding
-- Copyright   :  (c) The University of Glasgow, 2008-2009
-- License     :  see libraries/base/LICENSE
--
-- Maintainer  :  libraries@haskell.org
-- Stability   :  internal
-- Portability :  non-portable
--
-- Text codecs for I/O
--
-- /The API of this module is unstable and not meant to be consumed by the general public./
-- If you absolutely must depend on it, make sure to use a tight upper
-- bound, e.g., @base < 4.X@ rather than @base < 5@, because the interface can
-- change rapidly without much warning.
--
-----------------------------------------------------------------------------

module GHC.Internal.IO.Encoding (
        BufferCodec(..), TextEncoding(..), TextEncoder, TextDecoder, CodingProgress(..),
        latin1, latin1_encode, latin1_decode,
        utf8, utf8_bom,
        utf16, utf16le, utf16be,
        utf32, utf32le, utf32be,
        initLocaleEncoding,
        getLocaleEncoding, getFileSystemEncoding, getForeignEncoding,
        setLocaleEncoding, setFileSystemEncoding, setForeignEncoding,
        char8,
        mkTextEncoding,
        argvEncoding
    ) where

import GHC.Internal.Base
import GHC.Internal.IO.Exception
import GHC.Internal.IO.Buffer
import GHC.Internal.IO.Encoding.Failure
import GHC.Internal.IO.Encoding.Types
#if !defined(mingw32_HOST_OS)
import qualified GHC.Internal.IO.Encoding.Iconv as Iconv
#else
import qualified GHC.Internal.IO.Encoding.CodePage as CodePage
import GHC.Internal.Text.Read (reads)
#endif
import qualified GHC.Internal.IO.Encoding.Latin1 as Latin1
import qualified GHC.Internal.IO.Encoding.UTF8   as UTF8
import qualified GHC.Internal.IO.Encoding.UTF16  as UTF16
import qualified GHC.Internal.IO.Encoding.UTF32  as UTF32
import GHC.Internal.List
import GHC.Internal.Word

import GHC.Internal.Data.IORef
import GHC.Internal.Unicode (toUpper)
import GHC.Internal.IO.Unsafe (unsafePerformIO)

-- -----------------------------------------------------------------------------

-- | The Latin1 (ISO8859-1) encoding.  This encoding maps bytes
-- directly to the first 256 Unicode code points, and is thus not a
-- complete Unicode encoding.  An attempt to write a character greater than
-- @\'\\255\'@ to a 'System.IO.Handle' using the 'latin1' encoding will result in an
-- error.
latin1  :: TextEncoding
latin1 :: TextEncoding
latin1 = TextEncoding
Latin1.latin1_checked

-- | The UTF-8 Unicode encoding
utf8  :: TextEncoding
utf8 :: TextEncoding
utf8 = TextEncoding
UTF8.utf8

-- | The UTF-8 Unicode encoding, with a byte-order-mark (BOM; the byte
-- sequence 0xEF 0xBB 0xBF).  This encoding behaves like 'utf8',
-- except that on input, the BOM sequence is ignored at the beginning
-- of the stream, and on output, the BOM sequence is prepended.
--
-- The byte-order-mark is strictly unnecessary in UTF-8, but is
-- sometimes used to identify the encoding of a file.
--
utf8_bom  :: TextEncoding
utf8_bom :: TextEncoding
utf8_bom = TextEncoding
UTF8.utf8_bom

-- | The UTF-16 Unicode encoding (a byte-order-mark should be used to
-- indicate endianness).
utf16  :: TextEncoding
utf16 :: TextEncoding
utf16 = TextEncoding
UTF16.utf16

-- | The UTF-16 Unicode encoding (little-endian)
utf16le  :: TextEncoding
utf16le :: TextEncoding
utf16le = TextEncoding
UTF16.utf16le

-- | The UTF-16 Unicode encoding (big-endian)
utf16be  :: TextEncoding
utf16be :: TextEncoding
utf16be = TextEncoding
UTF16.utf16be

-- | The UTF-32 Unicode encoding (a byte-order-mark should be used to
-- indicate endianness).
utf32  :: TextEncoding
utf32 :: TextEncoding
utf32 = TextEncoding
UTF32.utf32

-- | The UTF-32 Unicode encoding (little-endian)
utf32le  :: TextEncoding
utf32le :: TextEncoding
utf32le = TextEncoding
UTF32.utf32le

-- | The UTF-32 Unicode encoding (big-endian)
utf32be  :: TextEncoding
utf32be :: TextEncoding
utf32be = TextEncoding
UTF32.utf32be

-- | The Unicode encoding of the current locale
--
-- @since base-4.5.0.0
getLocaleEncoding :: IO TextEncoding
{-# NOINLINE getLocaleEncoding #-}

-- | The encoding of the current locale, but allowing arbitrary
-- undecodable bytes to be round-tripped through it.
--
-- Do not expect the encoding to be Unicode-compatible: it could appear to be ASCII or anything else.
--
-- This 'TextEncoding' is used to decode and encode command line arguments
-- and environment variables on non-Windows platforms.
--
-- On Windows, this encoding *should not* be used if possible because
-- the use of code pages is deprecated: Strings should be retrieved
-- via the "wide" W-family of UTF-16 APIs instead
--
-- @since base-4.5.0.0
getFileSystemEncoding :: IO TextEncoding
{-# NOINLINE getFileSystemEncoding #-}

-- | The Unicode encoding of the current locale, but where undecodable
-- bytes are replaced with their closest visual match. Used for
-- the 'Foreign.C.String.CString' marshalling functions in "Foreign.C.String"
--
-- @since base-4.5.0.0
getForeignEncoding :: IO TextEncoding
{-# NOINLINE getForeignEncoding #-}

-- | Set locale encoding for your program. The locale affects
-- how 'Char's are encoded and decoded when serialized to bytes: e. g.,
-- when you read or write files ('GHC.Internal.System.IO.readFile'', 'GHC.Internal.System.IO.writeFile')
-- or use standard input/output ('GHC.Internal.System.IO.getLine', 'GHC.Internal.System.IO.putStrLn').
-- For instance, if your program prints non-ASCII characters, it is prudent to execute
--
-- > setLocaleEncoding utf8
--
-- This is necessary, but not enough on Windows, where console is
-- a stateful device, which needs to be configured using
-- @System.Win32.Console.setConsoleOutputCP@ and restored back afterwards.
-- These intricacies are covered by
-- <https://hackage.haskell.org/package/code-page code-page> package,
-- which offers a crossplatform @System.IO.CodePage.withCodePage@ bracket.
--
-- Wrong locale encoding typically causes error messages like
-- "invalid argument (cannot decode byte sequence starting from ...)"
-- or "invalid argument (cannot encode character ...)".
--
-- @since base-4.5.0.0
setLocaleEncoding :: TextEncoding -> IO ()
{-# NOINLINE setLocaleEncoding #-}

-- | @since base-4.5.0.0
setFileSystemEncoding :: TextEncoding -> IO ()
{-# NOINLINE setFileSystemEncoding #-}

-- | @since base-4.5.0.0
setForeignEncoding :: TextEncoding -> IO ()
{-# NOINLINE setForeignEncoding #-}

(IO TextEncoding
getLocaleEncoding, TextEncoding -> IO ()
setLocaleEncoding)         = TextEncoding -> (IO TextEncoding, TextEncoding -> IO ())
forall a. a -> (IO a, a -> IO ())
mkGlobal TextEncoding
initLocaleEncoding
(IO TextEncoding
getFileSystemEncoding, TextEncoding -> IO ()
setFileSystemEncoding) = TextEncoding -> (IO TextEncoding, TextEncoding -> IO ())
forall a. a -> (IO a, a -> IO ())
mkGlobal TextEncoding
initFileSystemEncoding
(IO TextEncoding
getForeignEncoding, TextEncoding -> IO ()
setForeignEncoding)       = TextEncoding -> (IO TextEncoding, TextEncoding -> IO ())
forall a. a -> (IO a, a -> IO ())
mkGlobal TextEncoding
initForeignEncoding

mkGlobal :: a -> (IO a, a -> IO ())
mkGlobal :: forall a. a -> (IO a, a -> IO ())
mkGlobal a
x = IO (IO a, a -> IO ()) -> (IO a, a -> IO ())
forall a. IO a -> a
unsafePerformIO (IO (IO a, a -> IO ()) -> (IO a, a -> IO ()))
-> IO (IO a, a -> IO ()) -> (IO a, a -> IO ())
forall a b. (a -> b) -> a -> b
$ do
    x_ref <- a -> IO (IORef a)
forall a. a -> IO (IORef a)
newIORef a
x
    return (readIORef x_ref, writeIORef x_ref)
{-# NOINLINE mkGlobal #-}

-- | @since base-4.5.0.0
initLocaleEncoding, initFileSystemEncoding, initForeignEncoding :: TextEncoding
{-# NOINLINE initLocaleEncoding #-}
-- N.B. initLocaleEncoding is exported for use in GHC.Internal.System.IO.localeEncoding.
-- NOINLINE ensures that this result is shared.

#if defined(javascript_HOST_ARCH)
initLocaleEncoding     = utf8
initFileSystemEncoding = utf8
initForeignEncoding    = utf8
#elif !defined(mingw32_HOST_OS)
-- It is rather important that we don't just call Iconv.mkIconvEncoding here
-- because some iconvs (in particular GNU iconv) will brokenly UTF-8 encode
-- lone surrogates without complaint.
--
-- By going through our Haskell implementations of those encodings, we are
-- guaranteed to catch such errors.
--
-- FIXME: this is not a complete solution because if the locale encoding is one
-- which we don't have a Haskell-side decoder for, iconv might still ignore the
-- lone surrogate in the input.
initLocaleEncoding     = unsafePerformIO $ mkTextEncoding' ErrorOnCodingFailure Iconv.localeEncodingName
initFileSystemEncoding = unsafePerformIO $ mkTextEncoding' RoundtripFailure     Iconv.localeEncodingName
initForeignEncoding    = unsafePerformIO $ mkTextEncoding' IgnoreCodingFailure  Iconv.localeEncodingName
#else
initLocaleEncoding :: TextEncoding
initLocaleEncoding     = TextEncoding
CodePage.localeEncoding
initFileSystemEncoding :: TextEncoding
initFileSystemEncoding = CodingFailureMode -> TextEncoding
CodePage.mkLocaleEncoding CodingFailureMode
RoundtripFailure
initForeignEncoding :: TextEncoding
initForeignEncoding    = CodingFailureMode -> TextEncoding
CodePage.mkLocaleEncoding CodingFailureMode
IgnoreCodingFailure
#endif

-- See Note [Windows Unicode Arguments] in rts/RtsFlags.c
-- On Windows we assume hs_init argv is in utf8 encoding.

-- | Internal encoding of argv
argvEncoding :: IO TextEncoding
#if defined(mingw32_HOST_OS)
argvEncoding :: IO TextEncoding
argvEncoding = TextEncoding -> IO TextEncoding
forall a. a -> IO a
forall (m :: * -> *) a. Monad m => a -> m a
return TextEncoding
utf8
#else
argvEncoding = getFileSystemEncoding
#endif

-- | An encoding in which Unicode code points are translated to bytes
-- by taking the code point modulo 256.  When decoding, bytes are
-- translated directly into the equivalent code point.
--
-- This encoding never fails in either direction.  However, encoding
-- discards information, so encode followed by decode is not the
-- identity.
--
-- @since base-4.4.0.0
char8 :: TextEncoding
char8 :: TextEncoding
char8 = TextEncoding
Latin1.latin1

-- | Look up the named Unicode encoding.  May fail with
--
--  * 'GHC.Internal.System.IO.Error.isDoesNotExistError' if the encoding is unknown
--
-- The set of known encodings is system-dependent, but includes at least:
--
--  * @UTF-8@
--
--  * @UTF-16@, @UTF-16BE@, @UTF-16LE@
--
--  * @UTF-32@, @UTF-32BE@, @UTF-32LE@
--
-- There is additional notation (borrowed from GNU iconv) for specifying
-- how illegal characters are handled:
--
--  * a suffix of @\/\/IGNORE@, e.g. @UTF-8\/\/IGNORE@, will cause
--    all illegal sequences on input to be ignored, and on output
--    will drop all code points that have no representation in the
--    target encoding.
--
--  * a suffix of @\/\/TRANSLIT@ will choose a replacement character
--    for illegal sequences or code points.
--
--  * a suffix of @\/\/ROUNDTRIP@ will use a PEP383-style escape mechanism
--    to represent any invalid bytes in the input as Unicode codepoints (specifically,
--    as lone surrogates, which are normally invalid in UTF-32).
--    Upon output, these special codepoints are detected and turned back into the
--    corresponding original byte.
--
--    In theory, this mechanism allows arbitrary data to be roundtripped via
--    a 'String' with no loss of data. In practice, there are two limitations
--    to be aware of:
--
--      1. This only stands a chance of working for an encoding which is an ASCII
--         superset, as for security reasons we refuse to escape any bytes smaller
--         than 128. Many encodings of interest are ASCII supersets (in particular,
--         you can assume that the locale encoding is an ASCII superset) but many
--         (such as UTF-16) are not.
--
--      2. If the underlying encoding is not itself roundtrippable, this mechanism
--         can fail. Roundtrippable encodings are those which have an injective mapping
--         into Unicode. Almost all encodings meet this criterion, but some do not. Notably,
--         Shift-JIS (CP932) and Big5 contain several different encodings of the same
--         Unicode codepoint.
--
-- On Windows, you can access supported code pages with the prefix
-- @CP@; for example, @\"CP1250\"@.
--
mkTextEncoding :: String -> IO TextEncoding
mkTextEncoding :: String -> IO TextEncoding
mkTextEncoding String
e = case Maybe CodingFailureMode
mb_coding_failure_mode of
    Maybe CodingFailureMode
Nothing -> String -> IO TextEncoding
forall a. String -> IO a
unknownEncodingErr String
e
    Just CodingFailureMode
cfm -> CodingFailureMode -> String -> IO TextEncoding
mkTextEncoding' CodingFailureMode
cfm String
enc
  where
    (String
enc, String
suffix) = (Char -> Bool) -> String -> (String, String)
forall a. (a -> Bool) -> [a] -> ([a], [a])
span (Char -> Char -> Bool
forall a. Eq a => a -> a -> Bool
/= Char
'/') String
e
    mb_coding_failure_mode :: Maybe CodingFailureMode
mb_coding_failure_mode = case String
suffix of
        String
""            -> CodingFailureMode -> Maybe CodingFailureMode
forall a. a -> Maybe a
Just CodingFailureMode
ErrorOnCodingFailure
        String
"//IGNORE"    -> CodingFailureMode -> Maybe CodingFailureMode
forall a. a -> Maybe a
Just CodingFailureMode
IgnoreCodingFailure
        String
"//TRANSLIT"  -> CodingFailureMode -> Maybe CodingFailureMode
forall a. a -> Maybe a
Just CodingFailureMode
TransliterateCodingFailure
        String
"//ROUNDTRIP" -> CodingFailureMode -> Maybe CodingFailureMode
forall a. a -> Maybe a
Just CodingFailureMode
RoundtripFailure
        String
_             -> Maybe CodingFailureMode
forall a. Maybe a
Nothing

mkTextEncoding' :: CodingFailureMode -> String -> IO TextEncoding
mkTextEncoding' :: CodingFailureMode -> String -> IO TextEncoding
mkTextEncoding' CodingFailureMode
cfm String
enc =
  case [Char -> Char
toUpper Char
c | Char
c <- String
enc, Char
c Char -> Char -> Bool
forall a. Eq a => a -> a -> Bool
/= Char
'-'] of
  -- UTF-8 and friends we can handle ourselves
    String
"UTF8"    -> TextEncoding -> IO TextEncoding
forall a. a -> IO a
forall (m :: * -> *) a. Monad m => a -> m a
return (TextEncoding -> IO TextEncoding)
-> TextEncoding -> IO TextEncoding
forall a b. (a -> b) -> a -> b
$ CodingFailureMode -> TextEncoding
UTF8.mkUTF8 CodingFailureMode
cfm
    String
"UTF16"   -> TextEncoding -> IO TextEncoding
forall a. a -> IO a
forall (m :: * -> *) a. Monad m => a -> m a
return (TextEncoding -> IO TextEncoding)
-> TextEncoding -> IO TextEncoding
forall a b. (a -> b) -> a -> b
$ CodingFailureMode -> TextEncoding
UTF16.mkUTF16 CodingFailureMode
cfm
    String
"UTF16LE" -> TextEncoding -> IO TextEncoding
forall a. a -> IO a
forall (m :: * -> *) a. Monad m => a -> m a
return (TextEncoding -> IO TextEncoding)
-> TextEncoding -> IO TextEncoding
forall a b. (a -> b) -> a -> b
$ CodingFailureMode -> TextEncoding
UTF16.mkUTF16le CodingFailureMode
cfm
    String
"UTF16BE" -> TextEncoding -> IO TextEncoding
forall a. a -> IO a
forall (m :: * -> *) a. Monad m => a -> m a
return (TextEncoding -> IO TextEncoding)
-> TextEncoding -> IO TextEncoding
forall a b. (a -> b) -> a -> b
$ CodingFailureMode -> TextEncoding
UTF16.mkUTF16be CodingFailureMode
cfm
    String
"UTF32"   -> TextEncoding -> IO TextEncoding
forall a. a -> IO a
forall (m :: * -> *) a. Monad m => a -> m a
return (TextEncoding -> IO TextEncoding)
-> TextEncoding -> IO TextEncoding
forall a b. (a -> b) -> a -> b
$ CodingFailureMode -> TextEncoding
UTF32.mkUTF32 CodingFailureMode
cfm
    String
"UTF32LE" -> TextEncoding -> IO TextEncoding
forall a. a -> IO a
forall (m :: * -> *) a. Monad m => a -> m a
return (TextEncoding -> IO TextEncoding)
-> TextEncoding -> IO TextEncoding
forall a b. (a -> b) -> a -> b
$ CodingFailureMode -> TextEncoding
UTF32.mkUTF32le CodingFailureMode
cfm
    String
"UTF32BE" -> TextEncoding -> IO TextEncoding
forall a. a -> IO a
forall (m :: * -> *) a. Monad m => a -> m a
return (TextEncoding -> IO TextEncoding)
-> TextEncoding -> IO TextEncoding
forall a b. (a -> b) -> a -> b
$ CodingFailureMode -> TextEncoding
UTF32.mkUTF32be CodingFailureMode
cfm
    -- On AIX, we want to avoid iconv, because it is either
    -- a) totally broken, or b) non-reentrant, or c) actually works.
    -- Detecting b) is difficult as you'd have to trigger the reentrancy
    -- corruption.
    -- Therefore, on AIX, we handle the popular ASCII and latin1 encodings
    -- ourselves. For consistency, we do the same on other platforms.
    -- We use `mkLatin1_checked` instead of `mkLatin1`, since the latter
    -- completely ignores the CodingFailureMode (TEST=encoding005).
    String
_ | Bool
isAscii -> TextEncoding -> IO TextEncoding
forall a. a -> IO a
forall (m :: * -> *) a. Monad m => a -> m a
return (CodingFailureMode -> TextEncoding
Latin1.mkAscii CodingFailureMode
cfm)
    String
_ | Bool
isLatin1 -> TextEncoding -> IO TextEncoding
forall a. a -> IO a
forall (m :: * -> *) a. Monad m => a -> m a
return (CodingFailureMode -> TextEncoding
Latin1.mkLatin1_checked CodingFailureMode
cfm)
#if defined(mingw32_HOST_OS)
    Char
'C':Char
'P':String
n | [(Word32
cp,String
"")] <- ReadS Word32
forall a. Read a => ReadS a
reads String
n -> TextEncoding -> IO TextEncoding
forall a. a -> IO a
forall (m :: * -> *) a. Monad m => a -> m a
return (TextEncoding -> IO TextEncoding)
-> TextEncoding -> IO TextEncoding
forall a b. (a -> b) -> a -> b
$ CodingFailureMode -> Word32 -> TextEncoding
CodePage.mkCodePageEncoding CodingFailureMode
cfm Word32
cp
    String
_ -> String -> IO TextEncoding
forall a. String -> IO a
unknownEncodingErr (String
enc String -> String -> String
forall a. [a] -> [a] -> [a]
++ CodingFailureMode -> String
codingFailureModeSuffix CodingFailureMode
cfm)
#else
    -- Otherwise, handle other encoding needs via iconv.

    -- Unfortunately there is no good way to determine whether iconv is actually
    -- functional without telling it to do something.
    _ -> do res <- Iconv.mkIconvEncoding cfm enc
            case res of
              Just e -> return e
              Nothing -> unknownEncodingErr (enc ++ codingFailureModeSuffix cfm)
#endif
  where
    isAscii :: Bool
isAscii = String
enc String -> [String] -> Bool
forall a. Eq a => a -> [a] -> Bool
`elem` [String]
asciiEncNames
    isLatin1 :: Bool
isLatin1 = String
enc String -> [String] -> Bool
forall a. Eq a => a -> [a] -> Bool
`elem` [String]
latin1EncNames
    asciiEncNames :: [String]
asciiEncNames = -- ASCII aliases specified by RFC 1345 and RFC 3808.
      [ String
"ANSI_X3.4-1968", String
"iso-ir-6", String
"ANSI_X3.4-1986", String
"ISO_646.irv:1991"
      , String
"US-ASCII", String
"us", String
"IBM367", String
"cp367", String
"csASCII", String
"ASCII", String
"ISO646-US"
      ]
    latin1EncNames :: [String]
latin1EncNames = -- latin1 aliases specified by RFC 1345 and RFC 3808.
      [ String
"ISO_8859-1:1987", String
"iso-ir-100", String
"ISO_8859-1", String
"ISO-8859-1", String
"latin1",
        String
"l1", String
"IBM819", String
"CP819", String
"csISOLatin1"
      ]


latin1_encode :: CharBuffer -> Buffer Word8 -> IO (CharBuffer, Buffer Word8)
latin1_encode :: CharBuffer -> Buffer Word8 -> IO (CharBuffer, Buffer Word8)
latin1_encode CharBuffer
input Buffer Word8
output = (State# RealWorld
 -> (# State# RealWorld, (CharBuffer, Buffer Word8) #))
-> IO (CharBuffer, Buffer Word8)
forall a. (State# RealWorld -> (# State# RealWorld, a #)) -> IO a
IO ((State# RealWorld
  -> (# State# RealWorld, (CharBuffer, Buffer Word8) #))
 -> IO (CharBuffer, Buffer Word8))
-> (State# RealWorld
    -> (# State# RealWorld, (CharBuffer, Buffer Word8) #))
-> IO (CharBuffer, Buffer Word8)
forall a b. (a -> b) -> a -> b
$ \State# RealWorld
st -> case EncodeBuffer#
Latin1.latin1_encode CharBuffer
input Buffer Word8
output State# RealWorld
st of
  (# State# RealWorld
st', CodingProgress
_why, CharBuffer
input', Buffer Word8
output' #) -> (# State# RealWorld
st', (CharBuffer
input', Buffer Word8
output') #) -- unchecked, used for char8
--latin1_encode = unsafePerformIO $ do mkTextEncoder Iconv.latin1 >>= return.encode

latin1_decode :: Buffer Word8 -> CharBuffer -> IO (Buffer Word8, CharBuffer)
latin1_decode :: Buffer Word8 -> CharBuffer -> IO (Buffer Word8, CharBuffer)
latin1_decode Buffer Word8
input CharBuffer
output = (State# RealWorld
 -> (# State# RealWorld, (Buffer Word8, CharBuffer) #))
-> IO (Buffer Word8, CharBuffer)
forall a. (State# RealWorld -> (# State# RealWorld, a #)) -> IO a
IO ((State# RealWorld
  -> (# State# RealWorld, (Buffer Word8, CharBuffer) #))
 -> IO (Buffer Word8, CharBuffer))
-> (State# RealWorld
    -> (# State# RealWorld, (Buffer Word8, CharBuffer) #))
-> IO (Buffer Word8, CharBuffer)
forall a b. (a -> b) -> a -> b
$ \State# RealWorld
st -> case DecodeBuffer#
Latin1.latin1_decode Buffer Word8
input CharBuffer
output State# RealWorld
st of
  (# State# RealWorld
st', CodingProgress
_why, Buffer Word8
input', CharBuffer
output' #) -> (# State# RealWorld
st', (Buffer Word8
input',CharBuffer
output') #)
--latin1_decode = unsafePerformIO $ do mkTextDecoder Iconv.latin1 >>= return.encode

unknownEncodingErr :: String -> IO a
unknownEncodingErr :: forall a. String -> IO a
unknownEncodingErr String
e = IOException -> IO a
forall a. HasCallStack => IOException -> IO a
ioException (Maybe Handle
-> IOErrorType
-> String
-> String
-> Maybe CInt
-> Maybe String
-> IOException
IOError Maybe Handle
forall a. Maybe a
Nothing IOErrorType
NoSuchThing String
"mkTextEncoding"
                                            (String
"unknown encoding:" String -> String -> String
forall a. [a] -> [a] -> [a]
++ String
e)  Maybe CInt
forall a. Maybe a
Nothing Maybe String
forall a. Maybe a
Nothing)