A Core Calculus of Classes and Objects

AbstractWe present an imperative calculus for a class-based language. By introducing classes as the basic object-oriented construct in a λ-calculus with records and references, we obtain a system with an intuitive operational semantics. Objects are instantiated from classes and represented by records. The type system for objects uses only functional, record, and reference types, and there is a clean separation between subtyping and inheritance. We demonstrate that the calculus is sound and sufficiently expressive to model advanced language features such as inheritance with method redefinition, multi-level encapsulation, and modular object construction