Summary

This chapter has showcased practical applications of functional programming using the Arrow library, along with implementations of various patterns discussed in previous chapters. The Arrow library provides a powerful toolset for functional programming, enhancing Kotlin’s capabilities in handling immutability, concurrent state modifications, resilience, and data manipulation.

Arrow also offers a sophisticated approach to error handling with its support for typed errors and the Either data type. Typed errors in Arrow enhance the robustness of Kotlin programs by making potential errors explicit and manageable at compile time. This approach promotes proactive error handling, contrasting with Kotlin’s traditional exception handling, which can lead to unpredictable runtime errors and code that is more challenging to maintain.

The Either type in Arrow is particularly effective, representing a value as either a success type or an error type. This distinction...