Observing intermediate structures in a parallel lazy functional language

Abstract

Due to the use of higher-order functions and laziness, debugging lazy functional programs is not a trivial task. Fortunately, several debuggers have appeared during the last years. However, the difficulty of the debugging process is increased when considering parallel extensions of lazy functional languages. Thus, it is necessary not only to develop practical debuggers, but also to provide a clear semantic environment to understand what the debuggers should do. In this paper we present a formal framework for debugging two different parallel extensions of the lazy functional language Haskell. In order to do that, we define an operational semantics model which allows us to deal with side-effects and parallelism. By doing so, we provide a formalization of a parallel debugger we have already implemented by extending the sequential debugger Hood.

A Semantic Framework to Debug Parallel Lazy Functional Languages

“…In this paper, we extend our previous work [61,63] to deal with two parallel extensions of Haskell. More precisely, we present a formal semantics allowing for dealing with Hood observations in the parallel languages GpH and Eden.…”