Object Inheritance Without Classes


Which comes first: the object or the class? Language designers enjoy the conceptual simplicity of object-based languages (such as Emerald or Self) while many programmers prefer the pragmatic utility of classical inheritance (such as Simula and Java). Programmers in object-based languages have a tendency to build libraries to support traditional inheritance, and language implementations are often contorted to the same end. In this paper, we revisit the relationship between classes and objects. We model various kinds of inheritance in the context of an object-oriented language whose objects are not defined by classes, and explain why class inheritance and initialisation cannot be modelled purely by delegation.


Timothy Jones, Michael Homer, James Noble, Kim Bruce

Published in

European Conference on Object-Oriented Programming (ECOOP), 2016
Michael Homer — 2018