Run-time exception when attempting to print a Unicode character

Question

Char is the type for Unicode characters in Haskell, and String is simply [Char] (i.e. a list of Char items). Here is some sim

Answer 1

On Windows, the fix is to tell the shell to use code page 65001 (instructions here), which puts Windows in "UTF-8 mode". It's not perfect, but for most characters you should see unicode characters handled much better.

Answer 2

I think this should count as a bug in GHC, but there is a workaround. The default encoding for all handles in a GHC program (except those opened in Binary mode) is just the encoding accepted by the console with no error handling. Fortunately you can add error handling with something like this.

makeSafe h = do
  ce' <- hGetEncoding h
  case ce' of
    Nothing -> return ()
    Just ce -> mkTextEncoding ((takeWhile (/= '/') $ show ce) ++ "//TRANSLIT") >>=
      hSetEncoding h

main = do
  mapM_ makeSafe [stdout, stdin, stderr]
  -- The rest of your main function.