Joanna's research interests involve improving the experience programmers have when debugging software written in Functional programming languages. She is particularly interested in type error debugging; looking at locating them when they occur and providing practical error messages.
Type error messages of compilers of statically typed functional languages are often inaccurate, making type error debugging hard. Many solutions to the problem have been proposed, but most have been evaluated only with short programs, that is, of fewer than 30 lines. In this paper we note that our own tool for delta debugging type errors scales poorly for large real-world programs. In response we present a new tool that applies a new algorithm for segmenting a large program before the delta debugging algorithm is applied. We propose a framework for evaluating type error debuggers and apply it to our new tool, demonstrating substantial improvement.