A transformational approach to debugging lazy functional programs
Jan Sparud · 1996
We describe a debugger for the lazy functional language Haskell. The basic idea is to transform a Haskell program into a program that evaluates to the same result as the original program but also produces an evaluation dependence tree describing how the result was obtained. If an error is detected while running the program, the programmer can browse the evaluation dependence tree, or use algorithmic debugging, in order to try to find the erroneous definition. The method is compared to other ways of debugging lazy functional programs. Some ideas for improvements are also presented.