Miryung Kim, Na Meng
Adding features and fixing bugs in software often require systematic edits which are similar but not identical changes to multiple code locations. Finding all relevant locations and making the correct edits is a tedious and error-prone process. This chapter presents several state-of-the art approaches to recommending program transformation in order to automate repetitive software changes. First, it discusses programming-by-demonstration (PBD) approaches that automate repetitive tasks by inferring a generalized action script from a user’s recorded actions. Second, it presents edit location suggestion approaches that only recommend candidate edit locations but do not apply necessary code transformations. Finally, it describes program transformation approaches that take code examples or version histories as input, automatically identify candidate edit locations, and apply context awareness, customization program transformations to generate a new program version. In particular, this chapter describes two concrete example-based program transformation approaches in detail, Sydit and Lase. These two approaches are selected for an in-depth discussion, because they handle the issue of both recommending change locations and applying transformations, and they are specifically designed to update programs as opposed to regular text documents. The chapter is then concluded with open issues and challenges of recommending program transformations.