Representing Concerns in Source Code

Many maintenance tasks address concerns, or features, that are not well modularized in the source code comprising a system. Sometimes, such non-localized concern code is the result of inadequate design. More often, it is the result of either unanticipated modifications or of a lack of expressibility in the technology available to the original designer to express interacting or overlapping concerns. The end result is that software developers must handle concern code scattered across a system’s source when modifying the concern or implementing a new feature that interacts with the concern. Existing approaches available to help software developers locate and manage the scattered implementation of concerns use a representation based on lines of source code. Because they do not explicitly express program structure, concern representations based on source code have inherent limitations when finding, describing, and analyzing concerns. First, since programmers tend to naturall