Concept as a Generalization of Class and Principles of the Concept-Oriented Programming

In the paper we describe a new construct which is referred to as concept and a new concept-oriented approach to programming. Concept generalizes conventional classes and consists of two parts: an objects class and a reference class. Each concept has a parent concept specifled via inclusion relation. Instances of reference class are passed by value and are intended to represent instances of child object classes. The main role of concepts consists in indirecting object representation and access. In concept-oriented programming it is assumed that a system consists of (i) conventional target business methods (BMs), and (ii) hidden representation and access (RA) methods. If conventional classes are used to describe only BMs then concepts allow the programmer to describe both types of functionality including its hidden intermediate functions which are automatically executed when objects are being accessed.