Kotlin Type Classes and Data Validation: An Arrow-Powered Approach
2025-04-17
This article explores the use of type classes in Kotlin for data validation. Using a fintech startup's user portfolio validation system as an example, the author demonstrates how to build a generic, reusable validation framework using the Arrow Kt library and Kotlin's context receivers. The article compares object-oriented and type class approaches, highlighting the advantages of type classes for maintainability and extensibility, and shows how to leverage Arrow's `EitherNel` type for functional error handling. The power of `zipOrAccumulate` for efficient validation is also explained.