Package: wnpp Severity: wishlist Owner: Kari Pahula <k...@debian.org> X-Debbugs-Cc: debian-devel@lists.debian.org, debian-scie...@lists.debian.org
* Package name : chuffed Version : 0.13.1 * URL : https://github.com/chuffed/chuffed * License : MIT/X Programming Lang: C++ Description : lazy clause generation CP solver Chuffed is a state of the art lazy clause solver designed from the ground up with lazy clause generation in mind. Lazy clause generation is a hybrid approach to constraint solving that combines features of finite domain propagation and Boolean satisfiability. It combines some of the advantages of finite domain constraint programming (high level model and programmable search) with some of the advantages of SAT solvers (reduced search by nogood creation, and effective autonomous search using variable activities). Chuffed only supports 3 different propagator priorities. Chuffed implements a number of global propagators (alldiff, inverse, minimum, table, regular, mdd, cumulative, disjunctive, circuit, difference). It also only supports two kinds of integer variables. Small integer variables for which the domain is represented by a byte string. And large integer variables for which the domain is represented only by its upper and lower bound (no holes allowed). All boolean variables and boolean constraints are handled by the builtin SAT solver. The solver, when run with lazy clause generation disabled, is somewhat comparable in speed with older versions of Gecode. The overhead from lazy clause generation ranges from negligible to perhaps around 100%. The search reduction, however, can reach orders of magnitude on appropriate problems. Thus lazy clause generation is an extremely important and useful technology. The easiest way to use Chuffed is as a backend to the MiniZinc constraint modelling language. Chuffed can also be used as a C++ library. The description is edited from upstream's description, it went into more detail than this about the implementation. For certain types of CP problems it works better than the alternatives. Chuffed is both a library and it provides a binary (fzn-chuffed). The library can be used as a dependency for both minizinc and minizinc-ide (which I maintain) and it provides an alternative flatzinc implementation for minizinc. I plan to maintain this under the Debian Science team. As of now upstream is building chuffed as a static library only but I'll try to convince them to provide a shared library before packaging it.
