Dynamic dispatch in Haskell

Question

Programs written in, for example, Java rely a lot on dynamic dispatch.

How are such programs expressed in functional languages such as Haskell?

In other word

Answer 1

Maybe you need ADT plus pattern matching ?

data Animal = Dog {dogName :: String}
            | Cat {catName :: String}
            | Unicorn

say :: Animal -> String
say (Dog {dogName = name}) = "Woof Woof, my name is " ++ name
say (Cat {catName = name}) = "Meow meow, my name is " ++ name
say Unicorn = "Unicorns do not talk"