Developing and Using Pluggable Type Systems

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 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.

We will:

• guide the audience through installing the Checker Framework, including how to set up Eclipse integration;
• teach how to use some of the checkers included with the Checker Framework;
• discuss other types of errors that one would like to be prevented at compile time;
• and teach how to write a new type checker to prevent the errors we come up with in our discussion.

Audience participation is desired! We encourage the audience to come prepared with a laptop with a working Java environment (Eclipse optional).

Additional material is available here: http://types.cs.washington.edu/c...