Hello all,

I'm very new to Haskell, but still I'd like to play with "tangible values", which I find really intriguing. After getting some kind help in haskell-beginners, I managed to compile and run a small example. Which is as follows:

------------------

{-# LANGUAGE OverlappingInstances, UndecidableInstances
           , IncoherentInstances, FlexibleContexts
           , TypeSynonymInstances, FlexibleInstances
           , MultiParamTypeClasses
           #-}
-- For ghc 6.6 compatibility
{-# OPTIONS -fglasgow-exts -fallow-overlapping-instances
-fallow-incoherent-instances #-}

---- Some GuiTV examples. See also the examples in TV.

import Data.List (sort)

-- my addition
import Data.Monoid
-- end my addition

import Interface.TV.UI
import Control.Arrow.DeepArrow
import Data.FunArr

-- TypeCompose
import Data.Title

-- To pick up the FunArr instance for OFun.
import Interface.TV.OFun()

reverseT :: CTV (String -> String)
reverseT = tv (oTitle "reverse" defaultOut) reverse

main = runUI reverseT

-----------------------

There were some warnings during compilation:

-----
[1 of 1] Compiling Main ( myexample.hs, myexample.o )

myexample.hs:7:11:
Warning: -fallow-overlapping-instances is deprecated: use
-XOverlappingInstances or pragma {-# LANGUAGE OverlappingInstances #-}
instead

myexample.hs:7:11:
Warning: -fallow-incoherent-instances is deprecated: use
-XIncoherentInstances or pragma {-# LANGUAGE IncoherentInstances #-}
instead
Linking myexample ...
martin@martin-desktop:/media/

ext4logicaUnTera/cosas_linux/programs/haskell/TV/examples/src/miejemplo$
ghc --make myexample.hs

myexample.hs:7:11:
Warning: -fallow-overlapping-instances is deprecated: use
-XOverlappingInstances or pragma {-# LANGUAGE OverlappingInstances #-}
instead

myexample.hs:7:11:
Warning: -fallow-incoherent-instances is deprecated: use
-XIncoherentInstances or pragma {-# LANGUAGE IncoherentInstances #-}
instead

-----

When I run it, I get a little window with the "reverse" title and two textboxes. However, when I write something in the upper box, nothing happens. I must say that when I use runIO instead of runUI in this little program, the interactive program does work. Only the GUI version doesn't.

So, the person who helped me (Brandon Allbery) said it's probably because of a GuiTV being a bit too old. He recommended me to ask about the issue here, at haskell-cafe.

Any suggestions? Maybe I should use GtkTV istead of GuiTV? Thanks in advance!

Martin O.B.