Towards Transitory Encapsulation

Encapsulation and information hiding are essential and fundamental to object-oriented and aspect-oriented programming languages. These principles ensure that one part of a program does not depend on assumptions on the internal structure and logic of other parts of the program. While this assumption allows for clearly defined modules, interfaces and interaction protocols when software is initially developed, it is possible that rigid encapsulation causes problems, such as brittleness, as software changes and evolves over time. We suggest that, just as the strength of type systems have relaxed over time, perhaps structural boundaries could, too be relaxed. Perhaps there could be a new kind of flexible encapsulation: one that allows non-permanent and flexible boundaries between program parts