Exploring API method parameter recommendations

A number of techniques have been developed that support method call completion. However, there has been little research on the problem of method parameter completion. In this paper, we first present a study that helps us to understand how developers complete method parameters. Based on our observations, we developed a recommendation technique, called Parc, that collects parameter usage context using a source code localness property that suggests that developers tend to collocate related code fragments. Parc uses previous code examples together with contextual and static type analysis to recommend method parameters. Evaluating our technique against the only available state-of-the-art tool using a number of subject systems and different Java libraries shows that our approach has potential. We also explore the parameter recommendation support provided by the Eclipse Java Development Tools (JDT). Finally, we discuss limitations of our proposed technique and outline future research directions.