A model for software plans

Even in well-designed software, some concerns can not be easily encapsulated due to their dependence on surrounding context. Such concerns are intermingled with each other and the context code, making it difficult for developers to reason independently about them. We have introduced software plans as an editor-based approach for addressing the tangling of context-dependent concerns. Software plans provide programmers with partial views of the overall software which present only that code related to concerns of current interest. The problem we address is that the traditional sequence-of-characters representation for code is poorly suited for software plans. It lacks the ability to accurately model the concerns associated with a code block, the relationships between code blocks, and the notion of multiple independent plans. In this paper, we present a formally-defined code/concern model that supports these capabilities and more. Using this model, we were able to implement a prototype editing tool that supports software plans.