The authors demonstrate that an algorithm implementation can be generalized into a composition of iterators and visitors (higher-order function objects). This is known from STL and from research in generic and functional programming, but it has not been demonstrated that the notion of iterators and visitors is sufficient for allowing polytypism in entire categories of algorithms without sacrificing on polymorphism in data structures. This paper emerges from recent experiments in the design of the Extended Function Library (EFLIB), a framework developed by Johan L. Larsson. These experiments show how large groups of algorithms can be classified using a set of visitors and iterators, and how data structures can be decomposed into lists and generators to achieve polytypism in an object-oriented language, thus making a program more open to change.
Project management (PM) is an integral part of software development. Although some OO processes avoid these important, people-related issues, OPEN addresses these fully in terms of Activities, Tasks, Techniques, and Roles that best exemplify practice in PM.
IT can best e-enable legacy systems by building reusable "eaiComponents" and an Enterprise Integration Middleware platform using a slew of available tools.