I have been interested in some of the concepts of functional programming lately. I have used OOP for some time now. I can see how I would build a fairly complex app in OOP. Each object would know how to do things that object does. Or anything it's parents class does as well. So I can simply tell Person().speak() to make the person talk.

But how do I do similar things in functional programming? I see how functions are first class items. But that function only does one specific thing. Would I simply have a say() method floating around and call it with an equivalent of Person() argument so I know what kind of thing is saying something?

So I can see the simple things, just how would I do the comparable of OOP and objects in functional programming, so I can modularize and organize my code base?

For reference, my primary experience with OOP is Python, PHP, and some C#. The languages that I am looking at that have functional features are Scala and Haskell. Though I am leaning towards Scala.

Basic Example (Python):

Animal(object):
    def say(self, what):
        print(what)

Dog(Animal):
    def say(self, what):
        super().say('dog barks: {0}'.format(what))

Cat(Animal):
    def say(self, what):
        super().say('cat meows: {0}'.format(what))

dog = Dog()
cat = Cat()
dog.say('ruff')
cat.say('purr')