An imperative, first-order calculus with object extension

Abstract

This paper presents an imperative object calculus designed to support class-based programming via a combination of extensible objects and encapsulation. This calculus simplifies the language presented in [17] in that, like C++ and Java, it chooses to support an imperative semantics instead of method specialization. We show how Java-style classes and "mixins" may be coded in this calculus, prove a type soundness theorem (via a subject reduction property), and give a sound and complete typing algorithm.