Reasoning About Parameterized Components with Dynamic Binding

Parameterized components provide an effective way of building scalable, reliable, flexible software. Techniques have been developed for reasoning about parameterized components in such a way that the relevant properties of a parameterized component can be predicted based on the restrictions on actual parameters. These techniques assume that the parameters are bound at compile-time. But in some cases, compile-time is just not late enough to instantiate a parameterized component; we would like to push instantiation into run-time instead. Doing this is sometimes dangerous, since we can no longer depend on the type system of the language to support our reasoning methods. In this paper, we present a specification notation and associated proof obligations, which when satisfied, allow us to extend the theories of reasoning about templates with static binding to dynamically-bound templates. We present these proof obligations in the context of the Service Facility pattern, which is a way of building templates whose parameters are dynamically bound.