Techniques for embedding executable specifications in software component interfaces

In this paper, we consider interface contracts as a possible mechanism for improving semantic integrity in component-based systems. A contract is essentially a formal specification interleaved with code and allowing a component or object to unambiguously specify its behaviour. The existing techniques that we survey are predominantly designed for object-oriented systems; we therefore investigate the extent to which they can be scaled up to the level of components, and embedded in interface specifications rather than code. We conclude that interleaved specifications are viable and useful at the level of components, but that future work is required to develop languages that can express the constraints that are important at this level of granularity.