Set-based Nondeterministic Declarative Programming in Singleton

Abstract

In this paper we present a declarative language that aims at combining valuable features of CLP languages—namely, nondeterminism, unification, constraint solving, dynamic data structures—with features of conventional programming languages we are accustomed to and that we do not want to give up, such as the syntactic form of programs, the deterministic control structures—in particular the iterative ones—, the notion of procedure and parameter passing. A key role to gain these objectives is played by the notion of sets: sets serve not only as a powerful data abstraction, but also as the (only) source of nondeterminism and as the main support for declarative (constraint) programming. Furthermore, semantics of the whole language can be described in terms of a CLP language with sets, which is used also as a straightforward implementation of the proposed language.