Executable specifications for Java programs

Abstract

In this thesis, we present a unified environment for running declarative specifications in the context of an imperative object-oriented programming language. Specifications are Alloy-like, written in first-order relational logic with transitive closure, and the imperative language for this purpose is Java. By being able to mix imperative code with executable declarative specifications, the user can easily express constraint problems in-place, i.e. in terms of the existing data structures and objects on the heap. After a solution is found, our framework will automatically update the heap to reflect the solution, so the user can continue to manipulate the program heap in the usual imperative way, without ever having to manually translate the problem back and forth between the host programming environment and the solver language. We show that this approach is not only convenient, but, for certain problems, like puzzles or NP-complete graph algorithms, it can also outperform the manual implementation. We also present an optimization technique that allowed us to run our tool on heaps with almost 2000 objects.