Full Haskell-like Type Class resolution in Java
Summary
An in-depth exploration of implementing Haskell-style type classes in Java using reflection, a small AST for Java types, and a unification-based witness-resolution engine. The article walks through type reification, parsing java.lang.reflect.Type into an AST, type unification, witness discovery, and recursive witness construction, including higher-kinded types via an encoding. It includes concrete examples (Show, Monoid, PrintAll, TyEq) and discusses trade-offs, caching, and potential compile-time resolution.