Lit Eval Data Add Neg Print Expression Product Line Operations

Delta-oriented programming (DOP) is a modular approach for implementing software product lines. Delta modules generalize feature modules by allowing removal of functionality. However, DOP requires to select one particular product as core product from which all products are generated. In this paper, we propose pure deltaoriented programming (Pure DOP) that is a conceptual simplification of traditional DOP. In Pure DOP, the requirement of one designated core product is dropped. Instead, program generation only relies on delta modules comprising program modifications such that Pure DOP is more flexible than traditional DOP. Furthermore, we show that Pure DOP is a true generalization of FOP and supports proactive, reactive and extractive product line engineering.