Design and Implementation of the GNU Prolog System
Daniel Díaz, Philippe Codognet · 2001
In this paper we describe the design and the implementation of the GNU Pro-log system. This system draws on our previous experience of compiling Prolog to C in the wamcc system and of compiling finite domain constraints in the clp(FD) system. The compilation scheme has however been redesigned in or-der to overcome the drawbacks of compiling to C. In particular, GNU-Prolog is based on a low-level mini-assembly platform-independent language that makes it possible to avoid compiling C code, and thus drastically reduces compilation time. It also makes it possible to produce small stand-alone executable files as the result of the compilation process. Interestingly, GNU Prolog is now com-pliant to the ISO standard, includes several extensions (OS interface, sockets, global variables, etc) and integrates a powerful constraint solver over finite domains. The system is efficient and in terms of performance is comparable with commercial systems for both the Prolog and constraint aspects. 1