A Common Framework Using Expected Types for Several Type Debugging Approaches

Many different approaches to type error debugging were developed independently. In this paper, we describe a new common framework for several type error debugging approaches. For this purpose, we introduce expected types from the outer context and propose a method for obtaining them. Using expected types, we develop three type error debugging approaches: enumeration of type error messages, type error slicing and (improved) interactive type error debugging. Based on our idea we implemented prototypes and confirm that the framework works well for type debugging.