My Constraint Programming Blog

Note: This is an abridged translation of my swedish blog post Constraint programming-nyheter samt nya MiniZinc-modeller, written 2008-12-27

Here is some news in constraint programming since about october 2008

My Constraint Programming page
In order to collect my constraint programming models/references, I have created My constraint programming page, which right now just links to my other constraint programming pages, i.e. "My XXXXXX page" where "XXXXX" in {MiniZinc, Choco, JaCoP}, see below.

MiniZinc

• version 0.9 is out and can be downloaded here. See the NEWS
  
• Two of my models is included as benchmarks. They are
  
  • debruijn_binary.mzn
    
  • quasiGroup7.mzn
    
  
  

(The model mortgage.mzn has been in the test directory for a while, due to a bug report.)

See My MiniZinc page

JaCoP

• Has moved to http://www.jacop.eu, and has a new Wiki.
  
• As of version 2.3 JaCoP is open source and downloadable.
  
• Some of my JaCoP models are in this distribution (edited to fit in the example structure):
  
  • DeBruijn.java
    
  • Diet.java
    
  • FurnitureMoving.java
    
  • LeastDiff.java
    
  • MineSweeper.java
    
  • SurvoPuzzle.java
    
  
  

See My JaCoP page.

Choco

• version 2.0.0.3 is released

Also, see My Choco page.

Minion/Tailor
Tailor is a nice modelling system which translates a Essence' (a a simpler version of the modelling language Essence) to Minion. Tailor is implemented in Java and contains a basic GUI for modelling.

I have written some Tailor models but they are not yet public, in part because the specification of Tailor/Essence' has not been stable. I will hopefully return to this later.

A note in passing: Some of my MiniZinc models are translations of Tailor/Essence' examples, e.g. futoshiki.mzn and K4P2GracefulGraph.mzn.

Global Constraint Catalog
The great Global constraint catalog was updated 2008-11-15, and has some new constraints, e.g. geost and other packning-constraints.

The site now have a new URL scheme. Instead of URL:s like http://www.emn.fr/x-info/sdemasse/gccat/sec4.5.html (for the global constraint alldifferent_cst), the URL is now http://www.emn.fr/x-info/sdemasse/gccat/Calldifferent_cst.html, i.e. .../C followed by the constraint name.

Most of the references to this site in my MiniZinc global constraint models use the old scheme. This may be adjusted in the future.

Gecode
Gecode has not released any new version since august 2008. However, the SVN version of Gecode/flatzinc (the MiniZinc solver) has been updated to support the new MiniZinc versions.

Gecode/R
Gecode/R is a Ruby interface to Gecode:

Gecode/R provides access to many, but not all, of the features in Gecode 2.2.0. Gecode/R is only a modelling interface, it does not provide support for e.g. creating new propagators.

Version 1.0 was released in september (2008).

I have - somewhat surprisingly - not worked with Gecode/R that much. Hopefully this will be corrected in the future.

Comet
Comet is a constraint programming system which uses "local search". It is now "commercialized" and version 1.02 (time limited) can be download via Dynadec.

This version is more competent and complete than the former beta version, but there is now even more differences to the great book Constrant-based local search written by Pascal Van Hentenryck and Laurent Michel.