Summary
This chapter has compared the respective merits of the
functional/modular and object models of organisation. Each tries to
address in its own way the problems of reusability and modifiability
of software. The main differences come from their type systems,
equality of types between parameters of functors and sub-typing in the
object model, and the evaluation of objects with late binding. The
two models do not succeed on their own in resolving the problem of the
extensibility of components, from whence we get the idea of a mixed
organization. This organization mix also permits new ways of
structuring.