Welcome to the JaCoP web

Java Constraint Programming solver - JaCoP in short.

This wiki is meant as main element to keep JaCoP community vibrant and in-touch with each other. Feel free to use this space to advertise/share your experience/work with JaCoP. We hope that you will help us to keep the documentation of JaCoP up-to-date with large number of examples and wiki pages explaining how to use CP technology and JaCoP. This is your chance to contribute back and let other people know your name and work. Great to have you here.

The authors of JaCoP are actively seeking and implementing as many solver techniques from Constraint Programming community as possible. The newest version of JaCoP has many features, such as pruning events, multiple constraint queues, special data structures to handle efficiently backtracking, iterative constraint processing, and many more. We often have to adapt published techniques so they can be efficiently used in the context of Java (specially its garbage collection techniques) and JaCoP architecture. JaCoP has number of global constraints implemented such as among, cumulative, element, circuit, assignment, global cardinality constraint, two different versions of diffn, regular constraint, three different versions of alldifferent, and two different versions of sum constraint, both negative and positive table constraints. The positive table constraints has three most recently published different variants of this constraint. The different versions of constraint implement different consistency methods with different computational and space complexities.

Every solver is different as solver applications impose different requirements and make some optimizations not possible. JaCoP facilitates constraint additions during search and extensive control over internal behavior of the solver. Almost every aspect of the solver can be tweaked. It is necessary if a solver is to be used in research when small things matter and can make your technique run much slower. All data structures are available for manipulation making implementing special search heuristics possible. It is also possible to implement user's own constraints with additional functions, which can be used later during search. Authors strive to achieve the right balance, between ease of use, ease of extension, and efficiency. JaCoP also supports and extends XCSP format for saving CSP's in XML format.

JaCoP is continuously under development. It is rarely fully backward compatible, as not only new constraints are added, but also internals of the engine are being improved. Authors have concentrated on the core functionality of the constraints, therefore there is no graphical interface available yet, which would help in programs debugging. There are a lot of examples, a short guide and Java Doc documentation, but authors would like to have more time to create more elaborate documentation.

There are quite many other constraint tools which have been implemented since the inception of JaCoP. Every system is different as they trade extendability, functionality, ease of development for efficiency in a different way. There are tools which sacrifice everything for efficiency, other tools which choose C++ over Java to avoid costs associated with executing Java programs. Our own experiments indicate that JaCoP is a very good Java solver, but it is slower than good C++ based solver. If you are looking for easy to use, easy to maintain, easy to extend and efficient solver written in Java then JaCoP is a must try for you. We are currently working hard to prepare version with more documentation which we will release under GNU AGPLv3! For a moment, since that version is not ready yet you need to contact RadoslawSzymanek by email to receive a copy of JaCoP.

As soon as you register, feel free to send an email to administrator of JaCoP wiki so your personal wiki page is created immediately. Afterwards, please write few sentences about yourself. If there is no question mark next to your name on wikipage TWikiUsers that means that an empty template for your personal wiki page has been created and you can edit it yourself. You will also get access to JaCoP wiki page and can start helping us making it a better wiki for all of us. Thanks. The registration process is not automatic and requires human-to-human interaction to keep spam-bots away.

JaCoP Documentation

• Welcome Guest - look here first
• Tutorial - 20 minutes JaCoP tutorial [todo]
• User's Guide - documentation for users [todo]
• Frequently Asked Questions - about JaCoP [todo]
• Resolved Bugs - move here the bugs which are no longer appearing
• Pending Bugs - announce the bugs which you encounter
• Reference Manual - documentation for advanced users [todo]
• JaCoP-2.3 Release Notes - describes what's new in this release
• Features requests - if you have an idea for additional functionality, here you can suggest it.
• Research Work implemented in JaCoP - describes different sources of inspiration for JaCoP
• Research Work which used JaCoP - describes research articles which have used JaCoP

JaCoP Web Utilities

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This site is running TWiki version TWiki-4.2.0, Tue, 22 Jan 2008, build 16278, Plugin API version 1.2

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Feel free to comment and participate in the wiki creation. This wiki is used for maintaining documentation of JaCoP development version (currently 2.2).

-- RadoslawSzymanek - 12 Feb 2008