Compositional Type-Checking of Delta-oriented Product Lines∗

Delta-oriented programming (DOP) is a compositional approach to flexibly implement software product lines. A delta-oriented product line is realized by a code base and a product line declaration. The code base consists of delta modules comprising modifications of object-oriented programs. The product line declaration defines how these modifications have to be combined to generate all possible products. This talk presents a foundation for compositional type checking of delta-oriented product lines of JAVA programs using a minimal core calculus for DOP. The calculus is equipped with a constraint-based type system that allows analyzing each delta module in isolation, so that the results of the analysis can be reused (like the delta module themselves) across different product lines. By combining the results of the delta module analysis with the product line declaration, it can be established whether all the products of the product line are well-typed according to the JAVA type system.