Enhancing the Visibility of Tightly Coupled Concerns with Generic Design

Separation of concerns (SoC) and generic design are two important principles to better control software complexity during development, maintenance and reuse. Some of the concerns identified at the concept level, can be separated at design/implementation level by modularization or unconventional techniques such a AspectJ or Hyper/J. Yet other concerns, however, may not be easily separable due to complex interactions with the rest of a program. In this paper, we show that generic design, in addition to simplifying program representation by avoiding repetitions, can also enhance the visibility of inseparable concerns, offering a weaker, but still useful form of SoC. The reason why generic design can penetrate software deeper than SoC is that generic design is based on the notion of similarity of program structures which is less formal and rigorous than separation of concerns. Paper’s contribution lies in explaining the inter-play between the two principles. In addition to the above observations, we show that there is an overlapping area where the goals of SoC and generic design, as well as means to achieve those goals, are the same.