Graph-based Implementation of a Functional Logic Language

We describe in this paper a graph narrowing machine that has been designed for the implementation of a higher-order functional logic language. To execute functional logic programs the machine must be capable of performing unification and backtracking. Some details about the implementation of the new machine on an Occam/transputer system are given. 1 Introduction During the last years, several attempts have been made to achieve an integration of functional and logic programming languages in order to combine the advantages of the different programming paradigms in a single framework [DeGroot, Lindstrom 86], [Bellia, Levi 86]. Usually one argues that logic languages have more expressive power than functional languages, while the latter have a simpler execution model, particularly suited to parallel implementations. We investigate in this paper the implementation of the functional logic language BABEL [Moreno, Rodr'iguez 89] on a graph reduction architecture. We extend the original versio..