Towards Assertion-based Debugging of Higher-Order (C)LP Programs

ABSTRACT. Higher-order constructs extend the expressiveness of first-order (Constraint) Logic Programming ((C)LP). At the same time assertions have been in use for some time in (C)LP systems helping programmers detect errors and validate programs. We report on our work towards filling this gap by extending the assertion-based approach to error detection and program validation to the higher-order context. We propose an extension of properties and assertions as used in (C)LP in order to be able to fully describe arguments that are predicates. We have developed syntax and semantics for (higher-order) properties and assertions, as well as for programs which contain such assertions, as well as several alternatives for performing run-time checking of such programs.