Re: [Haskell-beginners] Generate a list of all constructors

On Sat, Nov 14, 2015 at 07:56:45PM +0100, Kees Bleijenberg wrote:

In this piece of code

data Color = RED | BLUE | YELLOW

allColors :: [Color]

allColors = [RED, BLUE, YELLOW]

I have to remeber that if I add a Color, I have to add the color in allColors too.

Is there no better way to add all possible colors in allColors?

Yes, if you make Color instance of Enum. E.g.: data Color = RED | BLUE | YELLOW deriving (Show, Enum) allColors = enumFrom RED