When One Shell Isn't Enough: Scaling the Functional Core-Imperative Shell Pattern with Actors in C++

The article discusses the application of the "functional core – imperative shell" pattern in a modular and scalable architecture, particularly within an actor-based system. This approach aims to bridge traditional object-oriented programming (OOP) with functional programming paradigms while maintaining clear boundaries between different components.

Key Concepts

1. Functional Core: The pure functions that perform the main logic of your application without side effects.
2. Imperative Shell: The code responsible for handling side effects, such as input/output operations, state management, and interaction with external systems.

Modular Design Using Actors

The article introduces a design where each actor is an instance of the core-shell pattern:

• Core: Pure functions that process data and produce new states.
• Shell: Handles communication (e.g., message passing), side effects, and integrates the pure functions into the larger system.

Example: Input Handling and Game Logic

Consider two actors in a game application:

1. InputActor:

   • Core: Pure function that processes input events to determine player actions.
   • Shell: Handles receiving input events from external sources (e.g., keyboard, controller) and publishes messages representing player actions.

2. GameEngineActor:

Read the full article at DEV Community

---

Want to create content about this topic? Use Nemati AI tools to generate articles, social posts, and more.