Implementing the Strategy Pattern
Explore how to implement the Strategy pattern in C to encapsulate algorithms and make them interchangeable. Understand how this design supports the open-closed principle, allowing you to extend functionality without modifying existing code. This lesson demonstrates the use of function pointers to achieve dynamic behavior and flexible binding of strategies, enhancing maintainability and reducing the risk of bugs in software design.
The open-closed principle
Although mainly seen in the context of object-oriented literature, the open-closed principle defines properties attractive in the context of C too. The principle is summarized as “Software entities (classes, modules, functions, etc.) should be open for extension, but closed for modification.” (Martin)
According to the open-closed principle:
- Extending the behavior of an ideal module is achieved by adding code instead of changing the existing source.
- Following this principle minimizes the risk of introducing bugs in existing, tested code and typically raises the quality of the design by introducing loose coupling.
- Unfortunately, it is virtually impossible to design a module so that it is closed against all kinds of changes.
- Even trying to design software in such a way would overcomplicate the design far beyond suitability.
- Identifying which modules to close and what changes to close them against requires experience and a good understanding of the