Ownership type systems, based on the idea of enforcing unique access paths, have been
primarily focused on objects and top-level classes. However, existing models do not as …

NullPointerExceptions (NPEs) are a key source of crashes in modern Java programs.
Previous work has shown how such errors can be prevented at compile time via code …

The long-standing aspiration for software reuse has made astonishing strides in the past few
years. Many modern software development ecosystems now come with rich sets of publicly …

Reference immutability ensures that a reference is not used to modify the referenced object,
and enables the safe sharing of object structures. A pure method does not cause side-effects …

First-class functions dramatically increase expressiveness, at the expense of static
guarantees. In ALGOL or PASCAL, functions could be passed as arguments but never …

Type-and-effect systems are a well-studied approach for reasoning about the computational
behavior of programs. Nevertheless, there is only one example of an effect system that has …

JML is an ambitious project in formal specification and verification that has aimed to bring
value to Java programmers. As an international, cooperative effort, JML has been a uniting …

Object-oriented programming languages typically allow mutation of objects, but pure
methods are common too. There is great interest in recognizing which methods are pure …

Flow ty** is becoming a popular mechanism for ty** existing programs written in
untyped languages (eg JavaScript, Racket, Groovy). Such systems require intersections for …

An ongoing challenge for computer science is the development of a tool which automatically
verifies programs meet their specifications, and are free from runtime errors such as divide …