我想我会回答我自己的问题，并列出一个可能的答案，以下是我目前正在做的事情。很有可能一个人可以做得更好，这就是我问这个问题的原因！但我认为将以下内容提供给人们是有意义的。对于同一问题，它基本上是从 Python 到 Haskell 的这个 python 解决方法的翻译。它使用问题中提到的“选项 B”。
基本思想是您创建一个模块 IOUtil.hs，其中包含以下内容，您可以将其import放入您的代码中：
{-# LANGUAGE ForeignFunctionInterface #-}
{-# LANGUAGE CPP #-}
{-# LANGUAGE NoImplicitPrelude #-}
module IOUtil (
IOUtil.interact,
IOUtil.putChar, IOUtil.putStr, IOUtil.putStrLn, IOUtil.print,
IOUtil.getChar, IOUtil.getLine, IOUtil.getContents, IOUtil.readIO,
IOUtil.readLn,
ePutChar, ePutStr, ePutStrLn, ePrint,
trace, traceIO
) where
#ifdef mingw32_HOST_OS
import System.Win32.Types (BOOL, HANDLE, DWORD, LPDWORD, LPWSTR, LPCWSTR, LPVOID)
import Foreign.C.Types (CWchar)
import Foreign
import Prelude hiding (getContents, putStr, putStrLn) --(IO, Read, Show, String)
--import qualified System.IO
import qualified System.IO (getContents)
import System.IO hiding (getContents, putStr, putStrLn)
import Data.Char (ord)
{- <http://msdn.microsoft.com/en-us/library/ms683231(VS.85).aspx>
HANDLE WINAPI GetStdHandle(DWORD nStdHandle);
returns INVALID_HANDLE_VALUE, NULL, or a valid handle -}
foreign import stdcall unsafe "GetStdHandle" win32GetStdHandle :: DWORD -> IO (HANDLE)
std_OUTPUT_HANDLE = -11 :: DWORD -- all DWORD arithmetic is performed modulo 2^n
std_ERROR_HANDLE = -12 :: DWORD
{- <http://msdn.microsoft.com/en-us/library/aa364960(VS.85).aspx>
DWORD WINAPI GetFileType(HANDLE hFile); -}
foreign import stdcall unsafe "GetFileType" win32GetFileType :: HANDLE -> IO (DWORD)
_FILE_TYPE_CHAR = 0x0002 :: DWORD
_FILE_TYPE_REMOTE = 0x8000 :: DWORD
{- <http://msdn.microsoft.com/en-us/library/ms683167(VS.85).aspx>
BOOL WINAPI GetConsoleMode(HANDLE hConsole, LPDWORD lpMode); -}
foreign import stdcall unsafe "GetConsoleMode" win32GetConsoleMode :: HANDLE -> LPDWORD -> IO (BOOL)
_INVALID_HANDLE_VALUE = (intPtrToPtr $ -1) :: HANDLE
is_a_console :: HANDLE -> IO (Bool)
is_a_console handle
= if (handle == _INVALID_HANDLE_VALUE) then return False
else do ft <- win32GetFileType handle
if ((ft .&. complement _FILE_TYPE_REMOTE) /= _FILE_TYPE_CHAR) then return False
else do ptr <- malloc
cm <- win32GetConsoleMode handle ptr
free ptr
return cm
real_stdout :: IO (Bool)
real_stdout = is_a_console =<< win32GetStdHandle std_OUTPUT_HANDLE
real_stderr :: IO (Bool)
real_stderr = is_a_console =<< win32GetStdHandle std_ERROR_HANDLE
{- BOOL WINAPI WriteConsoleW(HANDLE hOutput, LPWSTR lpBuffer, DWORD nChars,
LPDWORD lpCharsWritten, LPVOID lpReserved); -}
foreign import stdcall unsafe "WriteConsoleW" win32WriteConsoleW
:: HANDLE -> LPWSTR -> DWORD -> LPDWORD -> LPVOID -> IO (BOOL)
data ConsoleInfo = ConsoleInfo Int (Ptr CWchar) (Ptr DWORD) HANDLE
writeConsole :: ConsoleInfo -> [Char] -> IO ()
writeConsole (ConsoleInfo bufsize buf written handle) string
= let fillbuf :: Int -> [Char] -> IO ()
fillbuf i [] = emptybuf buf i []
fillbuf i remain@(first:rest)
| i + 1 < bufsize && ordf <= 0xffff = do pokeElemOff buf i asWord
fillbuf (i+1) rest
| i + 1 < bufsize && ordf > 0xffff = do pokeElemOff buf i word1
pokeElemOff buf (i+1) word2
fillbuf (i+2) rest
| otherwise = emptybuf buf i remain
where ordf = ord first
asWord = fromInteger (toInteger ordf) :: CWchar
sub = ordf - 0x10000
word1' = ((shiftR sub 10) .&. 0x3ff) + 0xD800
word2' = (sub .&. 0x3FF) + 0xDC00
word1 = fromInteger . toInteger $ word1'
word2 = fromInteger . toInteger $ word2'
emptybuf :: (Ptr CWchar) -> Int -> [Char] -> IO ()
emptybuf _ 0 [] = return ()
emptybuf _ 0 remain = fillbuf 0 remain
emptybuf ptr nLeft remain
= do let nLeft' = fromInteger . toInteger $ nLeft
ret <- win32WriteConsoleW handle ptr nLeft' written nullPtr
nWritten <- peek written
let nWritten' = fromInteger . toInteger $ nWritten
if ret && (nWritten > 0)
then emptybuf (ptr `plusPtr` (nWritten' * szWChar)) (nLeft - nWritten') remain
else fail "WriteConsoleW failed.\n"
in fillbuf 0 string
szWChar = sizeOf (0 :: CWchar)
makeConsoleInfo :: DWORD -> Handle -> IO (Either ConsoleInfo Handle)
makeConsoleInfo nStdHandle fallback
= do handle <- win32GetStdHandle nStdHandle
is_console <- is_a_console handle
let bufsize = 10000
if not is_console then return $ Right fallback
else do buf <- mallocBytes (szWChar * bufsize)
written <- malloc
return . Left $ ConsoleInfo bufsize buf written handle
{-# NOINLINE stdoutConsoleInfo #-}
stdoutConsoleInfo :: Either ConsoleInfo Handle
stdoutConsoleInfo = unsafePerformIO $ makeConsoleInfo std_OUTPUT_HANDLE stdout
{-# NOINLINE stderrConsoleInfo #-}
stderrConsoleInfo :: Either ConsoleInfo Handle
stderrConsoleInfo = unsafePerformIO $ makeConsoleInfo std_ERROR_HANDLE stderr
interact :: (String -> String) -> IO ()
interact f = do s <- getContents
putStr (f s)
conPutChar ci = writeConsole ci . replicate 1
conPutStr = writeConsole
conPutStrLn ci = writeConsole ci . ( ++ "\n")
putChar :: Char -> IO ()
putChar = (either conPutChar hPutChar ) stdoutConsoleInfo
putStr :: String -> IO ()
putStr = (either conPutStr hPutStr ) stdoutConsoleInfo
putStrLn :: String -> IO ()
putStrLn = (either conPutStrLn hPutStrLn) stdoutConsoleInfo
print :: Show a => a -> IO ()
print = putStrLn . show
getChar = System.IO.getChar
getLine = System.IO.getLine
getContents = System.IO.getContents
readIO :: Read a => String -> IO a
readIO = System.IO.readIO
readLn :: Read a => IO a
readLn = System.IO.readLn
ePutChar :: Char -> IO ()
ePutChar = (either conPutChar hPutChar ) stderrConsoleInfo
ePutStr :: String -> IO ()
ePutStr = (either conPutStr hPutStr ) stderrConsoleInfo
ePutStrLn :: String -> IO ()
ePutStrLn = (either conPutStrLn hPutStrLn) stderrConsoleInfo
ePrint :: Show a => a -> IO ()
ePrint = ePutStrLn . show
#else
import qualified System.IO
import Prelude (IO, Read, Show, String)
interact = System.IO.interact
putChar = System.IO.putChar
putStr = System.IO.putStr
putStrLn = System.IO.putStrLn
getChar = System.IO.getChar
getLine = System.IO.getLine
getContents = System.IO.getContents
ePutChar = System.IO.hPutChar System.IO.stderr
ePutStr = System.IO.hPutStr System.IO.stderr
ePutStrLn = System.IO.hPutStrLn System.IO.stderr
print :: Show a => a -> IO ()
print = System.IO.print
readIO :: Read a => String -> IO a
readIO = System.IO.readIO
readLn :: Read a => IO a
readLn = System.IO.readLn
ePrint :: Show a => a -> IO ()
ePrint = System.IO.hPrint System.IO.stderr
#endif
trace :: String -> a -> a
trace string expr = unsafePerformIO $ do
traceIO string
return expr
traceIO :: String -> IO ()
traceIO = ePutStrLn
然后，您使用其中包含的 I/O 函数而不是标准库函数。他们会检测输出是否被重定向；WriteConsoleW如果不是（即如果我们正在写入“真实”控制台），那么我们将绕过通常的 Haskell I/O 函数并使用支持 unicode 的 win32 控制台函数直接写入win32 控制台。在非 Windows 平台上，条件编译意味着这里的函数只是调用标准库的函数。
如果您需要打印到标准错误，您应该使用 (eg) ePutStrLn，而不是hPutStrLn stderr; 我们没有定义一个hPutStrLn. （定义一个是读者的练习！）