System.IO.Encoding

This module provides a replacement for the normal (unicode unaware) IO functions of haskell. By using implicit parameters, it can be used almost as a drop-in replacement. For example, consider the following simple echo program:

main = do
  str <- getContents
  putStr str

To make this program process UTF-8 data, change the program to:

import Prelude hiding (getContents,putStr)
import System.IO.Encoding
import Data.Encoding.UTF8

main = do
  let ?enc = UTF8
  str <- getContents
  putStr str

Or, if you want to use the standard system encoding:

import Prelude hiding (getContents,putStr)
import System.IO.Encoding

main = do
  e <- getSystemEncoding
  let ?enc = e
  str <- getContents
  putStr str     

Documentation

getSystemEncoding :: IO DynEncoding

Returns the encoding used on the current system. Currently only supported on Linux-alikes.

getContents :: (Encoding e, ?enc :: e) => IO String

putStr :: (Encoding e, ?enc :: e) => String -> IO ()

putStrLn :: (Encoding e, ?enc :: e) => String -> IO ()

hPutStr :: (Encoding e, ?enc :: e) => Handle -> String -> IO ()

Like the normal hPutStr, but encodes the output using an encoding.

hPutStrLn :: (Encoding e, ?enc :: e) => Handle -> String -> IO ()

hGetContents :: (Encoding e, ?enc :: e) => Handle -> IO String

Like the normal hGetContents, but decodes the input using an encoding.

readFile :: (Encoding e, ?enc :: e) => FilePath -> IO String

writeFile :: (Encoding e, ?enc :: e) => FilePath -> String -> IO ()

appendFile :: (Encoding e, ?enc :: e) => FilePath -> String -> IO ()

getChar :: (Encoding e, ?enc :: e) => IO Char

hGetChar :: (Encoding e, ?enc :: e) => Handle -> IO Char

getLine :: (Encoding e, ?enc :: e) => IO String

hGetLine :: (Encoding e, ?enc :: e) => Handle -> IO String

putChar :: (Encoding e, ?enc :: e) => Char -> IO ()

hPutChar :: (Encoding e, ?enc :: e) => Handle -> Char -> IO ()

interact :: (Encoding e, ?enc :: e) => (String -> String) -> IO ()

print :: (Encoding e, Show a, ?enc :: e) => a -> IO ()

hPrint :: (Encoding e, Show a, ?enc :: e) => Handle -> a -> IO ()