> It feels a little redundant to have to manually list out all the elements when the information is known statically, and updating the list will be necessary if the Peg type changes. In Racket, writing a macro for this would be trivial, but alas, this is Haskell. Perhaps there is a way, I’m just not aware of it.
A reasonably clean way would be to define
data Color = Red | Green | Blue | Yellow | Orange | Purple
deriving (Enum, Bounded, Show)
and then (e.g. in ghci) you can do
>> [minBound .. maxBound] :: [Color]
[Red,Green,Blue,Yellow,Orange,Purple]
I often define the useful function
enumerate :: (Enum a, Bounded a) => [a]
enumerate = [minBound .. maxBound]
for exactly this purpose.
A reasonably clean way would be to define
and then (e.g. in ghci) you can do I often define the useful function for exactly this purpose.