Part V - Behavioral Patterns

Part V of "Software Design Patterns in Rust" covers Behavioral Patterns, which are essential for managing algorithms, relationships, and responsibilities within object-oriented systems. The section starts with the Chain of Responsibilities pattern, which allows a request to be passed along a chain of potential handlers until one of them handles it. Next, the Command pattern is explored, which encapsulates a request as an object, thereby allowing users to parameterize clients with queues, requests, and operations. The Iterator pattern provides a way to access the elements of an aggregate object sequentially without exposing its underlying representation. The Mediator pattern simplifies complex communications between related objects by centralizing communication in a mediator object. The Memento pattern offers a way to restore an object to its previous state, ideal for undo functionalities. The Observer pattern establishes a one-to-many dependency between objects so that when one object changes state, all its dependents are notified and updated automatically. The State pattern allows an object to change its behavior when its internal state changes, behaving as if it were instantiated from a different class. The Strategy pattern allows a method to be switched out at runtime by encapsulating the algorithm inside a class. The Template Method pattern defines the program skeleton of an algorithm in an operation, deferring some steps to subclasses. Finally, the Visitor pattern lets a new operation be added to a class without changing the class itself, enabling operations to be defined externally. This part equips readers with strategies for effectively managing complex behaviors and interactions within software applications.