Permission Assurance for Semantic Aspects of Design Patterns

A pattern is a general, reusable solution to a commonly occurring problem in software design. Programmers use patterns to produce effective and reliable software systems. However, pattern-related information usually reflects high-level user intentions that might not be available in source code when the coding process has been completed. Without proper documentation, those patterns may be concealed or destroyed during software maintenance and evolution. Being conscious of pattern occurrences can help understand source code and thereby provide deeper insight into a software product. In this paper, we argue that one should properly annotate object-oriented design patterns in source code and verify the consistency between patterns and code. This idea is demonstrated with the Singleton as well as the Strategy pattern, and we show how to assure some semantic aspects of these two patterns using a permission type system.