Throughout this introductory chapter, we've mentioned a couple of times that Elixir has protocols, with Enumerable being one of the examples. In this section, we'll dive into protocols and even define our own!
Protocols, like the behaviours we've seen in the last section, define a set of functions that have to be implemented. In that sense, both constructs serve as a way to achieve polymorphism in Elixir–being able to display multiple forms of behavior, but all linked to a single interface. While behaviours define a set of functions that a module needs to implement, and are thus tied to a module, protocols define a set of functions that a data type must implement. This means that, with protocols, we have data type polymorphism, ...
