Exploring Equality in Elixir with Funx

In this article, Joseph Koski explores the concept of equality in Elixir programming, highlighting its importance in various operations like de-duplication and membership checks. He introduces Funx, which provides a structured way to define equality rules. Through the example of playing cards, he illustrates how Funx allows developers to override Elixir’s default structural equality with domain-specific definitions using the `Eq` module and its DSL. By managing equality at the type level, developers can keep their code clean and organized, avoiding scattered equality checks across the codebase. Koski presents practical examples demonstrating how Funx simplifies operations that involve list manipulation and grouping based on custom equality definitions. The article emphasizes the significance of defining these rules clearly to maintain semantic integrity throughout the application.