Programming Elixir ≥ 1.6

Behaviours

An Elixir behaviour is nothing more than a list of functions. A module that declares that it implements a particular behaviour must implement all of the associated functions. If it doesn’t, Elixir will generate a compilation warning. You can think of a behaviour definition as being like an abstract base class in some object-oriented languages.

A behaviour is therefore a little like an interface in Java. A module uses it to declare that it implements a particular interface. For example, an OTP GenServer should implement a standard set of callbacks (handle_call, handle_cast, and so on). By declaring that our module implements that behaviour, we let the compiler validate that we have actually supplied the necessary interface. This reduces ...