Components as processes: An exercise in coalgebraic modeling

Components as processes: An exercise in coalgebraic modeling (preprint)
L. S. Barbosa. In S. F. Smith and C. L. Talcott, editors, FMOODS'2000: Formal Methods for Open Object-Oriented Distributed Systems, Stanford, USA, Kluwer Academic Publishers, pp 397--417, September, 2000.

Abstract

Software components, arising, typically, in systems' analysis and design, are characterized by a public interface and a private encapsulated state. They persist (and evolve) in time, according to some behavioural patterns. This paper is an exercise in modeling such components as coalgebras for some kinds of endofunctors on Set, capturing both (interface) types and behavioural aspects. The construction of component categories, cofibred over the interface space, emerges by generalizing the usual notion of a coalgebra morphism. A collection of composition operators as well as a generic notion of bisimilarity, are discussed.