Choco-solver
Choco-solver: A Java library for constraint programming - Published in JOSS (2022)
Science Score: 100.0%
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✓CITATION.cff file
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✓codemeta.json file
Found codemeta.json file -
✓.zenodo.json file
Found .zenodo.json file -
✓DOI references
Found 4 DOI reference(s) in README and JOSS metadata -
✓Academic publication links
Links to: joss.theoj.org -
✓Committers with academic emails
2 of 41 committers (4.9%) from academic institutions -
○Institutional organization owner
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✓JOSS paper metadata
Published in Journal of Open Source Software
Keywords
Keywords from Contributors
Repository
An open-source Java library for Constraint Programming
Basic Info
- Host: GitHub
- Owner: chocoteam
- License: bsd-4-clause
- Language: Java
- Default Branch: master
- Homepage: http://choco-solver.org/
- Size: 83.6 MB
Statistics
- Stars: 726
- Watchers: 47
- Forks: 147
- Open Issues: 76
- Releases: 38
Topics
Metadata Files
README.md
Choco-solver is an open-source Java library for Constraint Programming.
Current stable version is 5.0.0-beta.1 (17 Feb 2025).
Choco-solver comes with: - various type of variables (integer, boolean, set, graph and real), - various state-of-the-art constraints (alldifferent, count, nvalues, etc.), - various search strategies, from basic ones (first_fail, smallest, etc.) to most complex (impact-based and activity-based search), - explanation-based engine, that enables conflict-based back jumping, dynamic backtracking and path repair,
But also, facilities to interact with the search loop, factories to help modelling, many samples, etc.
Choco-solver is distributed under BSD 4-Clause License (Copyright (c) 1999-2025, IMT Atlantique).
Contact: - Choco-solver on Discord
Overview
java
// 1. Create a Model
Model model = new Model("my first problem");
// 2. Create variables
IntVar x = model.intVar("X", 0, 5);
IntVar y = model.intVar("Y", 0, 5);
// 3. Create and post constraints thanks to the model
model.element(x, new int[]{5,0,4,1,3,2}, y).post();
// 3b. Or directly through variables
x.add(y).lt(5).post();
// 4. Get the solver
Solver solver = model.getSolver();
// 5. Define the search strategy
solver.setSearch(Search.inputOrderLBSearch(x, y));
// 6. Launch the resolution process
solver.solve();
// 7. Print search statistics
solver.printStatistics();
Documentation, Support and Issues
The latest release points to binaries and source code.
You can get help on our google group. Most support requests are answered very fast.
Use the issue tracker here on GitHub to report issues. As far as possible, provide a Minimal Working Example.
Contributing
Anyone can contribute to the project, from the source code to the documentation. In order to ease the process, we established a contribution guide that should be reviewed before starting any contribution as it lists the requirements and good practices to ease the contribution process.
And thank you for giving back to choco-solver. Please meet our team of cho-coders :
- @cprudhom (Charles Prud'homme)
- @ArthurGodet (Arthur Godet)
- @jgFages (Jean-Guillaume Fages)
Supporting Choco with financial aid favors long-term support and development. Our expenses are varied: fees (GitHub organization, Domain name, etc), funding PhD students or internships, conferences, hardware renewal, ...
Download and installation
Requirements: * JDK 8+ * maven 3+
Choco-solver is available on Maven Central Repository, or directly from the latest release.
Snapshot releases are also available for curious.
In the following, we distinguish two usages of Choco:
- as a standalone library: the jar file includes all required dependencies,
- as a library: the jar file excludes all dependencies.
The name of the jar file terms the packaging:
- choco-solver-4.XX.Y-jar-with-dependencies.jar or
- choco-solver-4.XX.Y.jar.
- choco-parsers-4.XX.Y-jar-with-dependencies.jar or
- choco-parsers-4.XX.Y-light.jar or
- choco-parsers-4.XX.Y.jar.
The light tagged jar file is a version of the jar-with-dependencies one with dependencies from this archive.
A Changelog file is maintained for each release.
Inside a maven project
Choco is available on Maven Central Repository.
So you only have to edit your pom.xml to declare the following library dependency:
xml
<dependency>
<groupId>org.choco-solver</groupId>
<artifactId>choco-solver</artifactId>
<version>5.0.0-beta.1</version>
</dependency>
Note that if you want to test snapshot release, you should update your pom.xml with :
xml
<repository>
<id>sonatype</id>
<url>https://oss.sonatype.org/content/repositories/snapshots/</url>
<snapshots>
<enabled>true</enabled>
</snapshots>
</repository>
As a stand-alone library
The jar file contains all required dependencies. The next step is simply to add the jar file to your classpath of your application. Note that if your program depends on dependencies declared in the jar file, you should consider using choco as a library.
As a library
The jar file does not contains any dependencies, as of being used as a dependency of another application. The next step is to add the jar file to your classpath of your application and also add the required dependencies.
Dependencies
To declare continuous constraints, Ibex-2.8.7 needs to be installed (instructions are given on Ibex website).
Building from sources
The source of the released versions are directly available in the Tag section.
You can also download them using github features.
Once downloaded, move to the source directory then execute the following command
to make the jar:
$ mvn clean package -DskipTests
If the build succeeded, the resulting jar will be automatically
installed in your local maven repository and available in the target sub-folders.
Choco-solver dev team
Owner
- Name: chocoteam
- Login: chocoteam
- Kind: organization
- Repositories: 22
- Profile: https://github.com/chocoteam
JOSS Publication
Choco-solver: A Java library for constraint programming
Authors
TASC, IMT-Atlantique, LS2N-CNRS, Nantes, France
COSLING S.A.S., Nantes, France
Editor
Mehmet Hakan Satman
Tags
constraint programming constraint satisfaction problem constraint optimisation problem decision makingCitation (CITATION.cff)
# This CITATION.cff file was generated with cffinit.
# Visit https://bit.ly/cffinit to generate yours today!
cff-version: 1.2.0
title: Choco-solver
message: >-
If you use this software, please cite it using the
metadata from this file.
type: software
authors:
- given-names: Charles
family-names: Prud'homme
affiliation: 'IMT Atlantique, LS2N'
orcid: 'https://orcid.org/0000-0002-4546-9027'
- given-names: Jean-Guillaume
family-names: Fages
affiliation: COSLING S.A.S.
orcid: 'https://orcid.org/0000-0001-5638-4777'
identifiers:
- type: doi
value: 10.5281/zenodo.7185962
description: The concept DOI of the software
repository-code: 'https://github.com/chocoteam/choco-solver'
url: 'https://choco-solver.org/'
license: BSD-4-Clause
preferred-citation:
authors:
- given-names: Charles
family-names: Prud'homme
affiliation: IMT Atlantique
orcid: 'https://orcid.org/0000-0002-4546-9027'
- given-names: Jean-Guillaume
family-names: Fages
affiliation: COSLING S.A.S
orcid: 'https://orcid.org/0000-0001-5638-4777'
doi: "10.21105/joss.04708"
journal: "Journal of Open Source Software"
publisher:
-name: "The Open Journal"
title: "Choco-solver: A Java library for constraint programming"
type: article
start: 4708
volume: 7
issue: 78
year: 2022
GitHub Events
Total
- Create event: 39
- Release event: 2
- Issues event: 26
- Watch event: 36
- Delete event: 28
- Issue comment event: 63
- Push event: 78
- Pull request review event: 65
- Pull request review comment event: 64
- Pull request event: 70
- Fork event: 10
Last Year
- Create event: 39
- Release event: 2
- Issues event: 26
- Watch event: 36
- Delete event: 28
- Issue comment event: 63
- Push event: 78
- Pull request review event: 65
- Pull request review comment event: 64
- Pull request event: 70
- Fork event: 10
Committers
Last synced: 5 months ago
Top Committers
| Name | Commits | |
|---|---|---|
| cprudhom | c****m@m****r | 3,603 |
| Jean-Guillaume Fages | j****s@g****m | 1,379 |
| Dimitri | d****u@g****m | 162 |
| cprudhom | c****m@0****b | 153 |
| Arthur Godet | a****t@g****m | 48 |
| dependabot[bot] | 4****] | 44 |
| JLiangWaterloo | p****g@g****m | 36 |
| jfages07 | j****7@0****b | 28 |
| xavier lorca | x****a@e****r | 23 |
| Alexandre Lebrun | a****5@h****r | 22 |
| jussien | j****n@0****b | 21 |
| Arnaud Malapert | a****t@u****r | 17 |
| Fabien Hermenier | f****r@n****m | 9 |
| Choco Team | c****o@m****r | 8 |
| Guillaume Le Louët | g****t@g****m | 7 |
| njussien | n****n@g****m | 7 |
| Mohamed Wahbi | w****d@g****m | 5 |
| Jani Simomaa | j****a@g****m | 5 |
| Mehmet Hakan Satman | m****n@g****m | 4 |
| João Pedro Schmitt | s****o@g****m | 4 |
| xlorca | x****a@0****b | 3 |
| dependabot-preview[bot] | 2****] | 2 |
| Albert Hendriks | a****s@g****m | 2 |
| Olivier Pirson | o****i@y****r | 2 |
| Fabien Hermenier | f****r@u****r | 2 |
| Arnaud Letort | a****1@p****r | 2 |
| Erik Stevenson | e****n@g****m | 1 |
| Gabriel Homsi | g****i@g****m | 1 |
| HelgeS | H****S | 1 |
| Titouan Lorieul | t****l@s****r | 1 |
| and 11 more... | ||
Committer Domains (Top 20 + Academic)
Issues and Pull Requests
Last synced: 4 months ago
All Time
- Total issues: 82
- Total pull requests: 196
- Average time to close issues: 4 months
- Average time to close pull requests: 4 months
- Total issue authors: 31
- Total pull request authors: 16
- Average comments per issue: 1.73
- Average comments per pull request: 0.98
- Merged pull requests: 83
- Bot issues: 0
- Bot pull requests: 94
Past Year
- Issues: 19
- Pull requests: 81
- Average time to close issues: 20 days
- Average time to close pull requests: 17 days
- Issue authors: 13
- Pull request authors: 8
- Average comments per issue: 1.26
- Average comments per pull request: 0.53
- Merged pull requests: 21
- Bot issues: 0
- Bot pull requests: 39
Top Authors
Issue Authors
- cprudhom (20)
- matsc-at-sics-se (14)
- Holt59 (5)
- IgnaceBleukx (4)
- chocotrust (4)
- arnaud-m (3)
- jsimomaa (3)
- dimitri-justeau (3)
- o-fir (2)
- SYury (2)
- ptal (2)
- zy-nesime (2)
- fhermeni (1)
- bourreauEric (1)
- verenya (1)
Pull Request Authors
- dependabot[bot] (93)
- cprudhom (48)
- jgFages (16)
- ArthurGodet (15)
- fhermeni (4)
- jsimomaa (4)
- dimitri-justeau (3)
- paulk-asert (2)
- gadavidd (2)
- gjasper (1)
- JLLeitschuh (1)
- tlorieul (1)
- zy-nesime (1)
- Krizhnikov (1)
- glelouet (1)
Top Labels
Issue Labels
Pull Request Labels
Packages
- Total packages: 5
- Total downloads: unknown
- Total docker downloads: 1,062
-
Total dependent packages: 34
(may contain duplicates) -
Total dependent repositories: 121
(may contain duplicates) - Total versions: 106
repo1.maven.org: org.choco-solver:choco-solver
Open-source constraint solver.
- Homepage: http://choco-solver.org/
- Documentation: https://appdoc.app/artifact/org.choco-solver/choco-solver/
- License: BSD
-
Latest release: 4.10.18
published 11 months ago
Rankings
repo1.maven.org: org.choco-solver:choco-parsers
Provide parsers from FlatZinc, XCSP3 and MSP to Choco-solver.
- Homepage: http://choco-solver.org/
- Documentation: https://appdoc.app/artifact/org.choco-solver/choco-parsers/
- License: BSD
-
Latest release: 4.10.18
published 11 months ago
Rankings
repo1.maven.org: org.choco-solver:choco-sat
A SAT solver, used internally in choco-solver
- Homepage: http://choco-solver.org/
- Documentation: https://appdoc.app/artifact/org.choco-solver/choco-sat/
- License: BSD
-
Latest release: 4.10.6
published about 5 years ago
Rankings
repo1.maven.org: org.choco-solver:examples
Choco-solver in practice
- Homepage: http://choco-solver.org/
- Documentation: https://appdoc.app/artifact/org.choco-solver/examples/
- License: BSD
-
Latest release: 4.10.18
published 11 months ago
Rankings
repo1.maven.org: org.choco-solver:choco
A Free and Open-Source library dedicated to Constraint Programming.
- Homepage: http://choco-solver.org/
- Documentation: https://appdoc.app/artifact/org.choco-solver/choco/
- License: BSD 4-Clause License
-
Latest release: 4.10.18
published 11 months ago
Rankings
Dependencies
- actions/checkout v2 composite
- github/codeql-action/analyze v1 composite
- github/codeql-action/autobuild v1 composite
- github/codeql-action/init v1 composite
- actions/checkout v2 composite
- docker/build-push-action v1.1.0 composite
- actions/checkout v2 composite
- actions/upload-artifact v1 composite
- openjournals/openjournals-draft-action master composite
- actions/checkout v3 composite
- actions/setup-java v3 composite
- actions/upload-artifact v3 composite
- actions/checkout v2 composite
- actions/setup-java v3 composite
- gradle 4.8.1-jdk10 build
- openjdk 10.0.1-10-jdk build
- args4j:args4j 2.33 compile
- org.choco-solver:choco-parsers 4.10.11-SNAPSHOT
- org.choco-solver:choco-solver 4.10.11-SNAPSHOT
- args4j:args4j 2.33
- org.antlr:antlr4 4.9.3
- org.antlr:antlr4-runtime 4.9.3
- org.choco-solver:choco-solver 4.10.11-SNAPSHOT
- org.xcsp:xcsp3-tools 2.1
- net.sf.trove4j:trove4j 3.0.3
- org.choco-solver:choco-parsers 4.10.11-SNAPSHOT
- org.choco-solver:choco-solver 4.10.11-SNAPSHOT
- org.testng:testng 7.5 test
- dk.brics.automaton:automaton 1.11-8
- org.jgrapht:jgrapht-core 1.4.0
- org.knowm.xchart:xchart 3.8.3