Suitability of Object and Aspect Oriented Languages for Software Maintenance

Program maintenance is an important and frequently a difficult part of the software life cycle. One reason for its difficulty is the presence of crosscutting concerns; aspects of a program that cannot be confined to a single program component. Crosscutting concerns defy the standard wisdom of program design that individual components should be highly cohesive (they should address only one concern) and loosely coupled (they should not share concerns with other components). We consider several approaches to a simple maintenance task in both object-oriented and aspect-oriented languages, analyzing how well they maintain high cohesion and low coupling. We conclude that none of these approaches is entirely satisfactory, and present a few changes to aspect oriented programming language design that would better support maintenance in the face of crosscutting concerns.