Demoen, Bart × García de la Banda, M Harvey, W Marriott, K Stuckey, P #
Proceedings of the International Conference on Principles and Practice of Constraint Programming vol:1713 pages:174-188
International Conference on Principles and Practice of Constraint Programming location:Alexandria, Virginia, USA date:october 1999
Experience using constraint programming to solve real-life problems has shown that finding an efficient solution to the problem often requires experimentation with different constraint solvers or even building a problem-specific constraint solver. HAL is a new constraint logic programming language expressly designed to facilitate this process. It provides a well-defined solver interface, mutable global variables for implementing a constraint stare, and dynamic scheduling for combining, extending and writing new constraint solvers. Equally importantly, HAL supports semi-optional type, mode and determinism declarations. These allow natural constraint specification by means of type overloading, better compile-time error checking and generation of more efficient run-time code.