hearth-hkt-derivation

What problem does it solve?

Polymorphic (kind * -> *) type class derivation across Scala 2.13 and Scala 3, enabling consistent derivation for F[_] like Functor, Traverse, and ConsK, while hiding the complexity of higher-kinded generics behind Hearth macros.

Core Features & Use Cases

• Erased approach for macro-based derivation to avoid runtime reflection and maintain binary compatibility.
• Two-probe field classification to distinguish direct, invariant, and nested fields for efficient instance assembly.
• Bridge methods for type constructor summoning to handle nested F[_] fields.
• Runtime helpers for erased HKT calls to implement bounds-safe operations across different F instances.
• ConsK carry-and-absorb algorithm to compose fields for higher-kinded type constructors.

Quick Start

Invoke the hearth macro-based derivation to generate a Functor instance for your F[_] and inspect the resulting implementation.