Repairing Regex-Dependent String-Manipulation Programs

Abstract We present a new Programming-by-Examples (PBE) approach to repairing regex-dependent string-manipulation programs. Our approach has the following key features: (1) the support for a wide range of functions including regex-dependent functions such as , , , list manipulation functions such as , , , and numerical functions such as , , , (2) the support for real-world regexes with non-standard semantics such as greedy/lazy Kleene star and extensions such as lookarounds and backreferences, (3) the focus on a method-chaining style that starts the chain of calls with a regex-dependent function, reflecting a code style used in the real-world, and (4) novel origin-enriched examples that allow users to communicate intensional behavior of programs in addition to the standard extension behavior communicated via ordinary input-output examples, and a novel origin-tracking semantics that formally defines when a program conforms to the behavior stipulated by such examples. We have implemented our approach as a tool named and evaluated it on real-world benchmarks collected from GitHub and StackOverflow. The results show that finds high-quality repairs efficiently.