A Framework for Examining Topical Locality in Object-Oriented Software

The software entities of an object-oriented system should be organized in such a way that "spatial relatedness entails semantic relatedness". We refer this as the tenet of "topical locality" and argue that it is fundamental for the code base to be navigable. In this paper, we propose a novel experimental framework to test this key tenet and use large-scale open-source projects to assess three relationships. In particular, we find that: (1) class name along with header comments conveys class body\´s topic; (2) a code line is indicative of its surroundings; and (3) a contiguous code fragment may serve as a snapshot of the entire class. Our work not only shows the foundations necessary for the success of many code navigation approaches, but also opens avenues for further tool enhancements.