Object-oriented programming in Smalltalk and Ada

Abstract

Though Ada and Modula-2 are not objectoriented languages, an object-oriented viewpoint is crucial for effective use of their module facilities. It is therefore instructive to compare the capabilities of a modular language such as Ada with an archetypal object-oriented language such as Smalltalk. The comparison in this paper is in terms of the basic properties of encapsulation, inheritance and binding, with examples given in both languages. This comparison highlights the strengths and weaknesses of both types of languages from an object-oriented perspective. It also provides a basis for the application of experience from Smalltalk and other object-oriented languages to increasingly widely used modular languages such as Ada and Modula-2.