Swift Functional Programming - Second Edition

SRP

The SRP states that every class should have a single responsibility, where a responsibility is defined as a reason to change.

This principle supports the anti-pattern where large classes play multiple roles. Classes can be large for a few reasons. A core principle of OOP is the binding of the data structure to behavior. The problem is that optimizing for data--structure encapsulation not only weakens composition characteristics, but also hides the underlying problem of explicit state. As a result, OOP code typically contains many data structures, with relatively few functions per data structure. Adding methods to a class brings pressure on the SRP, and reducing the number of methods can either make the data structure difficult to compose ...