Designing an Elixir-specific Type System

Guillaume presented his PhD research on developing a static type system for Elixir under the guidance of type systems expert Giuseppe Castagna and José Valim. Their goal is to create a system that utilizes types at compile-time to analyze program behavior and detect bugs more effectively. Guillaume introduced novel type concepts such as set-theoretic types, negation types, union and intersection types, polymorphic types, and refined types for maps and protocols. These additions aim to improve code expressiveness, handle pattern matching robustly, and offer better feedback during development. With gradual typing, existing dynamic code and new static types can coexist, enabling a smooth transition for developers. Guillaume also covered the challenges of integrating a type system with Elixir's dynamic nature, and the team's work on formalization and prototype implementation. The next steps involve community feedback, publication, and working towards integrating the type system into the Elixir compiler. Currently, a prototype is available for conference attendees to experiment with, indicative of the research's experimental phase.