A pluggable type system extends a language's built-in type system to confer additional compile-time guarantees. We will explain the theory and practice of pluggable types. The material is relevant for researchers who wish to apply type theory, and for anyone who wishes to increase confidence in their code. After this session, you will have the knowledge to: analyze a problem to determine whether pluggable type-checking is appropriate; design a domain-specific type system; implement a simple type-checker (in as little as 4 lines of code!); scale a simple type-checker to more sophisticated properties; and better appreciate both object-oriented types and flexible verification techniques.
While the theory is general, our hands-on exercises will use a state-of-the-art system, the Checker Framework, that works for the Java language, scales to millions of lines of code, and is being adopted in the research and industrial communities. Such a framework enables researchers to easily evaluate their type systems in the context of a widely-used industrial language, Java. It enables non-researchers to verify their code in a lightweight way and to create custom analyses. And it enables students to better appreciate type system concepts.
This tutorial is part of the RiSE Seminar, and is organized by the Austrian Society for Rigorous Systems Engineering.