A presentation of the formal underpinnings of object-oriented programming languages.

Although the theory of object-oriented programming languages is far from complete, this book brings together the most important contributions to its development to date, focusing in particular on how advances in type systems and semantic models can contribute to new language designs.The fifteen chapters are divided into five parts: Objects and Subtypes, Type Inference, Coherence, Record Calculi, and Inheritance. The chapters are organized approximately in order of increasing complexity of the programming language constructs they consider - beginning with variations on Pascal- and Algol-like languages, developing the theory of illustrative record object models, and concluding with research directions for building a more comprehensive theory of object-oriented programming languages.Part I discusses the similarities and differences between "objects" and algebraic-style abstract data types, and the fundamental concept of a subtype. Parts II-IV are concerned with the "record model" of object-oriented languages. Specifically, these chapters discuss static and dynamic semantics of languages with simple object models that include a type or class hierarchy but do not explicitly provide what is often called dynamic binding. Part V considers extensions and modifications to record object models, moving closer to the full complexity of practical object-oriented languages.Carl A. Gunter is Professor in the Department of Computer and Information Science at the University of Pennsylvania. John C. Mitchell is Professor in the Department of Computer Science at Stanford University.

Proceedings

by Luea Cardelli Ever since Strachey's work in the 1960's, polymorphism has been classified into the parametric and overloading varieties. Parametric polymorphism has been the subject of extensive study for over two decades. Overloading, on the other hand, has often been considered too ad hoc to deserve much attention even though it has been, in some form, an ingredient of virtually every programming lan guage (much more so than parametric polymorphism). With the introduction of object-oriented languages, and in particular with multiple-dispatch object-oriented languages, overloading has become less of a programming convenience and more of a fundamental feature in need of proper explanation. This book provides a compelling framework for the study of run-time over loading and of its interactions with subtyping and with parametric polymorphism. The book also describes applications to object-oriented programming. This new framework is motivated by the relatively recent spread of programming languages that are entirely based on run-time overloading; this fact probably explains why this subject was not investigated earlier. Once properly understood, overloading reveals itself relevant also to the study of older and more conventional (single dispatch) object-oriented languages, clarifying delicate issues of covariance and contravariance of method types, and of run-time type analysis. In the final chapters, a synthesis is made between parametric and overloading polymorphism.

This comprehensive examination of the main approaches to object-oriented language explains key features of the languages in use today. Class-based, prototypes and Actor languages are all examined and compared in terms of their semantic concepts. This book provides a unique overview of the main approaches to object-oriented languages. Exercises of varying length, some of which can be extended into mini-projects are included at the end of each chapter. This book can be used as part of courses on Comparative Programming Languages or Programming Language Semantics at Second or Third Year Undergraduate Level. Some understanding of programming language concepts is required.