The CHRat language is a modular version of the Constraint Handling Rules language CHR, called CHRat for modular CHR with ask and tell. Any constraint defined in a CHRat component can be reused both in rules and guards in another CHRat component to define new constraint solvers. This extension is currently implemented by a simple syntactic transformation.
- François Fages, Cleyton Mario de Oliveira Rodrigues, Thierry Martinez, Modular CHR with ask and tell, Fifth Workshop on Constraint Handling Rules, 2008. [PDF]
Solver Hierarchy
The current distribution includes the following solvers:
| leq | union_find | [SF04] | booleans | fd | |||||||
| min | rational_tree | ||||||||||
| graphs | comparisons |
Online Top-level
Some examples:
leq:leq(X, Y), min:min(X, Y, Z).union_find:make(t), union_find:make(u), rational_tree:fun(t, f, 1), rational_tree:argument(t, 1, t), rational_tree:argument(t, 1, u), rational_tree:fun(u, F, N).
Downloads
The CHRat compiler is distributed as a command-line tool which compiles the bunch of CHRat components enumerated in the command-line parameters (plus dependencies) into a single CHR file. The distribution includes a top-level loop to use CHRat solvers in a convenient way.
The current version is v0.1.
The current compiler is implemented in CHRat and generated CHR files are currently written for the K.U. Leuven implementation of CHR distributed with SWI-Prolog . The current top-level is implemented in CHRat.
- Binaries for Linux (intel 32) + Sources + Solvers: [tar.gz] or [tar.bz2] or [zip]
- Binaries for Mac OS X (intel 32) + Sources + Solvers: [tar.gz] or [tar.bz2] or [zip]
- Binaries for Windows (intel 32) + Sources + Solvers: [tar.gz] or [tar.bz2] or [zip]
- Sources only + Solvers: [tar.gz] or [tar.bz2] or [zip]
History
- v0.1 released on 23 July 2008
Bibliography
- [FOM08] François Fages, Cleyton Mario de Oliveira Rodrigues, Thierry Martinez, Modular CHR with ask and tell, Fifth Workshop on Constraint Handling Rules, 2008. [PDF]
- [SF04] Tom Schrijvers and Thom Frühwirth, Implementing and Analysing Union-Find in CHR, K.U.Leuven, Department of Computer Science, Report CW 389, July, 2004. [report]