Re: [Haskell-cafe] question about GADT and deriving automatically a Show instance

Denis Kasak wrote:

Note that all of this would work even without explicit quantification since you have already specified that Person accepts an argument of kind Gender. In other words, this works as expected:

data Person :: Gender -> * where Dead :: Person a Alive :: { name :: String , weight :: Float , father :: Person b } -> Person a

deriving instance Show (Person a)

Thanks so much, it is now perfectly clear. A lot of things learned with this dummy example. TP