A Web based Course Scheduler in Constraint Logic Programming: Interactive Computing with Constraints

This paper describes the design of a web based scheduler program and its implementation in the constraint logic programming language clp(FD). We give a formal description of this implementation using the interaction semantics of action languages recently developed by the authors. The clp code employs a port of the PiLLoW library and was compiled via C to executable code (using technology based on wamcc for Prolog) to be run as a CGI script. The implementation is based on the course modules description currently being used in the School of Informatics at City University. It integrates constraints concerning module pre-and post-requisites as described in the course guide, and computes a schedule for course modules to be run for 1st, 2nd and 3rd year BSc students. The paper also explores issues involved in programming in logic languages on the web, and shows that CLP can ooer an attractive environment for developing applications which can be delivered over the Internet/Intranet.