Soft Objects: A Paradigm for Object Oriented Programming

Abstract

This paper introduces soft objects, a new paradigm for object oriented programming. This paradigm replaces the traditional notion of object classes with the specification of transforming procedures which transform simpler objects into more complicated objects. These transforming procedures incrementally construct new objects by adding new state or providing handlers for new messages. Unlike other incremental approaches (e.g. the inherited exist handlers of Object Logo [Drescher, 1987]), transforming procedures are strict functions which always return new objects; rather than conflating objects and object abstractions (classes), soft objects distinctly separates objects and their abstractions. The composition of these transforming procedures replaces the inheritance schemes of class oriented approaches; order of composition of transforming procedure makes explicit the inheritance indeterminancies introduced by multiple super classes. Issues regarding semantics, efficiency, and security are discussed in the context of several alternative implementation models and the code of a complete implementation is provided in an appendix.