Interactive Extraction of Examples from Existing Code

Programmers frequently learn from examples produced and shared by other programmers. However, it can be challenging and time-consuming to produce concise, working code examples. We conducted a formative study where 12 participants made examples based on their own code. This revealed a key hurdle: making meaningful simplifications without introducing errors. Based on this insight, we designed a mixed-initiative tool, CodeScoop, to help programmers extract executable, simplified code from existing code. CodeScoop enables programmers to "scoop" out a relevant subset of code. Techniques include selectively including control structures and recording an execution trace that allows authors to substitute literal values for code and variables. In a controlled study with 19 participants, CodeScoop helped programmers extract executable code examples with the intended behavior more easily than with a standard code editor.