Multi-paradigm Programming in Maude

Santiago Escobar

Abstract: Modern multi-paradigm programming languages combine the most important features of functional programming, logic programming, concurrent programming, and constraint programming. Multi-paradigm programming applied to the Maude specification language would replace the functional viewpoint by an equational viewpoint while retaining and extending the other features. A former paper illustrated how many features available in modern functional logic languages are easily definable and simulated in Maude, and showed how Maude goes beyond standard practices in the functional logic area by using, e.g. equational properties such as associativity and commutativity or order-sorted information. As a practical application the paper used the Missionaries and Cannibals equational logic program given by Goguen and Meseguer for Eqlog in the eighties. However, no relevant execution results were included due to the preliminary implementation of narrowing in Maude. In this paper we provide more relevant execution results by changing the focus from narrowing with rules (i.e., symbolic reachability) into narrowing with variant equations (i.e., equational unification), the latter now implemented in Maude 2.7.1 with very good performance.