{-# LANGUAGE CPP #-}

{- |

Module : ./Common/IO.hs

Description : wrapper module for changed IO handling since ghc-6.12.1

Copyright : (c) Christian Maeder DFKI GmbH 2010

License : GPLv2 or higher, see LICENSE.txt

Maintainer : Christian.Maeder@dfki.de

Stability : provisional

Portability : portable

reading and writing files changed between ghc-6.10.4 and ghc-6.12.1 from

latin1 to utf8.

This module allows to continue reading and writing latin1 (HetCASL) files.

However, this module does not support to write utf8 files with ghc-6.10.4 or

earlier versions.

The encoding only effects the contents. The encoding of file names is always

utf8.

-}

module Common.IO

( Enc (..)

, readEncFile

, writeEncFile

, setStdEnc

, catchIOException

) where

import System.IO

import Control.Exception as Exception

catchIOException :: a -> IO a -> IO a

catchIOException d a = catchJust (\ e ->

fromException e :: Maybe IOException) a . const $ return d

data Enc = Latin1 | Utf8 deriving Show

readEncFile :: Enc -> String -> IO String

writeEncFile :: Enc -> String -> String -> IO ()

-- | set encoding of stdin and stdout

setStdEnc :: Enc -> IO ()

#if __GLASGOW_HASKELL__ < 612

readEncFile _ = readFile

writeEncFile _ = writeFile

setStdEnc _ = return ()

#else

readEncFile c f = do

hdl <- openFile f ReadMode

hSetEncoding hdl $ case c of

Utf8 -> utf8

Latin1 -> latin1

hGetContents hdl

writeEncFile c f txt = withFile f WriteMode $ \ hdl -> do

hSetEncoding hdl $ case c of

Utf8 -> utf8

Latin1 -> latin1

hPutStr hdl txt

setStdEnc c = do

hSetEncoding stdin $ case c of

Utf8 -> utf8

Latin1 -> latin1

hSetEncoding stdout $ case c of

Utf8 -> utf8

Latin1 -> latin1

#endif