Help developers use functype functional programming patterns in their TypeScript projects. Use this skill when converting imperative/OOP code to functional patterns, looking up functype APIs and methods, handling nulls with Option, managing errors with Either/Try, composing effects with IO (lazy effects, typed errors, dependency injection, retry), working with immutable collections like List and Set, running async operations with Task, or making HTTP requests with Http (typed fetch wrapper).
Assist contributors working on the functype library codebase. Use this skill when creating new data structures, implementing functional interfaces (Functor, Monad, Foldable), adding tests, debugging library internals, or understanding functype's Scala-inspired architecture patterns including the Base pattern, HKT system, and Companion utilities.