For starters, you could squish these down into something like

...

flagToString :: Flag -> Maybe String flagToString (Filter s) = Just s flagToString (DateFormat s) = Just s ... flagToString _ = Nothing

What am I saying?! This wouldn't work! Sorry for the noise. -- Eric Kow http://www.loria.fr/~kow PGP Key ID: 08AC04F9 Merci de corriger mon français.