data Week = Mon | Tue | Wed | Thu | Fri | Sat | Sun deriving(Eq, Enum, Show)

day = Tue
main = do
  if day == Tue then
     print day
  else
     putStr "not Tue"
  print (enumFrom Mon) -- week
  print (enumFromTo Mon Fri) -- weekday
  print (enumFromTo Sat Sun) -- weekend

-- Local Variables: --
-- compile-command: "ghc test1.hs; ./test1" --
-- End: --