Getting a list of all possible data type values in Haskell

Question

If I have a data type say:

data Color = Red | Yellow | Green

Is there a way I can turn this into a list of type [Color] getting all possibl

Answer 1

Here is an example of using this technique to parse enums with Parsec

data FavoriteColor = Maroon | Black | Green  | Red | 
                     Blue   | Pink  | Yellow | Orange
                             deriving (Show, Read, Enum, Bounded)

And the parsec parser

parseColor :: Parser FavoriteColor           
parseColor = fmap read . foldr1 (<|>) $ map (try . string . show) 
  [ minBound :: FavoriteColor ..] 

of course the try could could be applied by better by pattern matching and a few other things could make it nicer but this is just an example of some usage of the technique.