An Interpretation of Objects and Object Types

Abstract

We present an interpretation of typed object-oriented concepts in terms of well-understood, purely procedural concepts. More precisely, we give a compositional subtype-preserving translation of a basic object calculus supporting method invocation, functional method update, and subtyping, into the polymorphic λ-calculus with recursive types and subtyping. The translation techniques apply also to an imperative version of the object calculus which includes in-place method update and object cloning. Finally, the translation easily extends to "Self types" and other interesting object-oriented constructs.