kotlin-functional-first

What problem does it solve?

Functional-first Kotlin emphasizes pure functions, immutability, and composition to reduce OO complexity, enabling safer, more testable code.

Core Features & Use Cases

• Stateless functions at top-level for clarity and testability; examples include pure transformations and unidirectional data flow between layers.
• Sealed hierarchies over enums when payload is needed, value classes for domain primitives, and data classes with defaults and copy.
• Extension functions and higher-order functions to compose behavior without boilerplate classes; error handling via Result or domain types.
• Use Case: Refactor a module to replace Manager-style classes with pure functions and small data carriers to improve testability and readability.

Quick Start

Refactor a Kotlin module to start using top-level pure functions for core logic and immutable data structures.