Haskell : How do you print 2 byte chars in haskell ?

あらゆる意味におけるコメントを強く強く希望します。

comp.lang.functional で拾ったネタです．

print, show では，2バイト文字を表示できませんが，putStr, putStrLn では表示可能です．

• Prelude.hs での定義

  primitive putStr		 :: String -> IO ()
  
  print     :: Show a => a -> IO ()
  print      = putStrLn . show
  
  putStrLn  :: String -> IO ()
  putStrLn s = do putStr s
  		putChar '\n'
  
  hugsPutStr :: String -> IO ()
  hugsPutStr  = putStr
  
  class Show a where
      show      :: a -> String
      showsPrec :: Int -> a -> ShowS
      showList  :: [a] -> ShowS
  
      -- Minimal complete definition: show or showsPrec
      show x          = showsPrec 0 x ""
      showsPrec _ x s = show x ++ s
      showList []     = showString "[]"
      showList (x:xs) = showChar '[' . shows x . showl xs
  		      where showl []     = showChar ']'
  			    showl (x:xs) = showChar ',' . shows x . showl xs
  

• ログ

  Haskell 98 mode: Restart with command line option -98 to enable extensions
  
  Reading file "Krause:usr:lang:Haskell:Hugs 98:lib:Prelude.hs":
  
  Hugs session for:
  Krause:usr:lang:Haskell:Hugs 98:lib:Prelude.hs
  Type :? for help
  Prelude> print ""
  ""
  
  (26 reductions, 48 cells)
  Prelude> print "abcv"
  "abcv"
  
  (97 reductions, 151 cells)
  Prelude> print "あいうえお"
  "\130\160\130\162\130\164\130\166\130\168"
  
  (407 reductions, 598 cells)
  Prelude> 
  Prelude> show ""
  "\"\""
  (36 reductions, 64 cells)
  Prelude> show "abc"
  "\"abc\""
  (142 reductions, 220 cells)
  Prelude> show "あいうえお"
  "\"\\130\\160\\130\\162\\130\\164\\130\\166\\130\\168\""
  (1076 reductions, 1522 cells)
  Prelude> 
  Prelude> putStr ""
  
  (6 reductions, 8 cells)
  Prelude> putStr "abc"
  abc
  (6 reductions, 11 cells)
  Prelude> putStr "あいうおえ"
  あいうおえ
  (6 reductions, 18 cells)
  Prelude> 
  Prelude> putStrLn ""
  
  
  (13 reductions, 25 cells)
  Prelude> putStrLn "abc"
  abc
  
  (12 reductions, 20 cells)
  Prelude> putStrLn "あいうえお"
  あいうえお
  
  (12 reductions, 27 cells)
  Prelude> 
  Prelude> hugsPutStr　""
  ERROR: Unrecognised character `\129' in column 11
  Prelude> hugsPutStr "abc"
  abc
  (6 reductions, 11 cells)
  Prelude> hugsPutStr "あいうえお"
  あいうえお
  (6 reductions, 18 cells)
  Prelude>