Choco-solver: A Java library for constraint programming

Abstract

Constraint Programming (CP) is a powerful programming paradigm for solving combinatorial search problems (Rossi et al., 2006). CP is at the intersection of artificial intelligence, computer science, operations research, and many other fields. One of the strengths of the paradigm is the wide variety of constraints it offers. CP is both a rich declarative language for describing combinatorial problems and a set of algorithms and techniques for solving them automatically. Choco-solver is Java library for constraint programming which was created in the early 2000s. Since then, the library has evolved a great deal, but ease of use has always been a guiding principle in its development. The Choco-solver API is designed to reduce entry points to a minimum and thus simplifies modelling for users. The wide variety of constraints available allows the user to describe his problem as naturally as possible. The black-box approach to solving allows everyone to focus on modelling. However, Choco-solver is also open and modifiable. The implementation of new constraints (Ouellet & Quimper, 2022) or strategies for exploring the search space (Fages & Prud’Homme, 2017; Li et al., 2021) is therefore possible.