Refactoring Delta-Oriented Product Lines to achieve Monotonicity
This work addresses the challenge of analyzing complex software product lines for developers, though it is incremental as it builds on existing delta-oriented programming methods.
The paper tackles the problem of simplifying delta-oriented product lines by refactoring them into monotonic forms, presenting algorithms that achieve this with formal correctness and complexity analysis.
Delta-oriented programming (DOP) is a flexible transformational approach to implement software product lines. In delta-oriented product lines, variants are generated by applying operations contained in delta modules to a (possibly empty) base program. These operations can add, remove or modify named elements in a program (e.g., classes, methods and fields in a Java program). This paper presents algorithms for refactoring a delta-oriented product line into monotonic form, i.e., either to contain add and modify operations only (monotonic increasing) or to contain remove and modify operations only (monotonic decreasing). Because of their simpler structure, monotonic delta-oriented product lines are easier to analyze. The algorithms are formalized by means of a core calculus for DOP of product lines of Java programs and their correctness and complexity are given.