[Haskell-beginners] Newbie unicode utf8 question

[Manfred Lotz]

Hi there,
I want to read a unicode file and print it to screen. My terminal was
unintentionally set to POSIX locale and that was the reason that it
didn't work properly.

When I added two hSetEncoding statements it worked fine, even under
POSIX.


Test file uc.in contains a simple line
	Möbius Château

Here is the small test program I tried:

<-----------------------------snip---------------------------->
module Main where

import System.IO
import Text.Printf

    
main :: IO ()
main = do
  h <- openFile "uc.in" ReadMode 
  hSetEncoding h utf8
  hSetEncoding stdout utf8
  s <- hGetContents h
  print s
  putStrLn $ "File contains line: " ++ s
  printf "File contains line: %s\n" s
<-----------------------------snap---------------------------->


Both putStrLn, and printf work fine. 

When setting a different locale, e.g. en_GB.iso88591 then both putStrLn
and printf work fine even if I haven't set encoding to utf in the
source.

Then I discovered System.IO.UTF8. However, when I use this as below
then the output is garbled.

<-----------------------------snip---------------------------->
module Main where

import System.IO
import System.IO.UTF8 as U
import Text.Printf

    
main :: IO ()
main = do
  h <- openFile "uc.in" ReadMode 
  hSetEncoding stdout utf8
  s <- U.hGetContents h
  U.print s
  U.putStrLn $ "File contains line: " ++ s
  printf "File contains line: %s\n" s
<-----------------------------snap---------------------------->


Any idea why this won't work.



-- 
Manfred