Developers perform small-scale reuse tasks to save time and to increase the quality of their code, but due to their small scale, the costs of such tasks can quickly outweigh their benefits. Existing approaches focus on locating source code for reuse but do not support the integration of the located code within the developer's system, thereby leaving the developer with the burden of performing integration manually. This paper presents an approach that uses the developer's context to help integrate the reused source code into the developer's own source code. The approach approximates a theoretical framework (higher-order anti-unification modulo theories), known to be undecidable in general, to determine candidate correspondences between the source code to be reused and the developer's current (incomplete) system. This approach has been implemented in a prototype tool, called Jigsaw, that identifies and evaluates candidate correspondences greedily with respect to the highest similarity. Situations involving multiple candidate correspondences with similarities above a defined threshold are presented to the developer for resolution. Two empirical evaluations were conducted: an experiment comparing the quality of Jigsaw's results against suspected cases of small-scale reuse in an industrial system; and case studies with two industrial developers to consider its practical usefulness and usability issues.
Generated: 9/9/2008