Achieving polymorphism in functional programming

Question

I\'m currently enjoying the transition from an object oriented language to a functional language. It\'s a breath of fresh air, and I\'m finding myself much more productive t

Answer 1

Who said

defining pure functions separately from data

is best practice?

If you want polymorphic objects, you need objects. In a functional language, objects can be constructed by glueing together a set of "pure data" with a set of "pure functions" operating on that data. This works even without the concept of a class. In this sense, a class is nothing but a piece of code that constructs objects with the same set of associated "pure functions".

And polymorphic objects are constructed by replacing some of those functions of an object by different functions with the same signature.

If you want to learn more about how to implement objects in a functional language (like Scheme), have a look into this book:

Abelson / Sussman: "Structure and Interpration of Computer programs"