My Prolog Resources

Prolog is a logic programming language and it lends itself well to the type of programming required in knowledge representation. I have used Prolog extensively over the last 7 years, for a variety of tasks, most prominently for the high-level control of our soccer robots in several RoboCup tournaments (German Open and World-Cup in 2003 and 2004).

I here collect some of the Prolog code I have written over the years which I conjecture might be useful to others. They are all free for use under the GNU General Public Licence. The code sometimes involves external C-libraries. In those cases, make sure to compile the provided c-files before trying to use the code. The methods involving c-code are specific to The ECLiPSe Constraint Programming System. I expect the rest to work on many Prolog implementation, but have so far only tested on ECLiPSe and SWI-Prolog.

• cfheaps.pl: A heaps implementation following "Introductions to Algorithms" by Thomas H. Cormen, Charles E. Leiserson, Ronald L. Rivest, and Clifford Stein. I use the non-logical setarg/3 to implement constant time array manipulations.
  Typical use: a priority queue, as required, for instance, in best-first search (e.g. A*).
  Tested on: ECLiPSe, SWI-Prolog.
• rdtsc_profile.tgz: An improved profiler, using the external C-interface and the rdtsc assembler call to read the CPU clock ticks.
• bresenham.pl: Bresenham's line drawing algorithm for 2D ray tracing.