GS Collections has been migrated to the Eclipse Foundation, re-branded as Eclipse Collections. https://www.eclipse.org/collections/
Java Scala
Latest commit fa8bf3e Feb 19, 2016 @itohro itohro [GSCOLLECT-1675] Update version number to 7.0.4-SNAPSHOT in the build.
git-svn-id: svn+ssh://gscollections.svn.services.gs.com/svnroot/gscollections-svn/trunk@938 d5c9223b-1aff-41ac-aadd-f810b4a99ac4
Permalink
Failed to load latest commit information.
.idea [GSCOLLECT-1521] Fix the iteration order of several iteration patterns. Jan 17, 2015
.settings [GSCOLLECT-35] Initial import. Jan 5, 2012
acceptance-tests [GSCOLLECT-1675] Update version number to 7.0.4-SNAPSHOT in the build. Feb 19, 2016
collections-api [GSCOLLECT-1675] Update version number to 7.0.4-SNAPSHOT in the build. Feb 19, 2016
collections-testutils [GSCOLLECT-1675] Update version number to 7.0.4-SNAPSHOT in the build. Feb 19, 2016
collections [GSCOLLECT-1675] Update version number to 7.0.4-SNAPSHOT in the build. Feb 19, 2016
gs-collections-code-generator-ant [GSCOLLECT-1675] Update version number to 7.0.4-SNAPSHOT in the build. Feb 19, 2016
gs-collections-code-generator-maven-plugin [GSCOLLECT-1675] Update version number to 7.0.4-SNAPSHOT in the build. Feb 19, 2016
gs-collections-code-generator [GSCOLLECT-1675] Update version number to 7.0.4-SNAPSHOT in the build. Feb 19, 2016
gs-collections-forkjoin [GSCOLLECT-1675] Update version number to 7.0.4-SNAPSHOT in the build. Feb 19, 2016
jmh-scala-tests [GSCOLLECT-1675] Update version number to 7.0.4-SNAPSHOT in the build. Feb 19, 2016
jmh-tests [GSCOLLECT-1675] Update version number to 7.0.4-SNAPSHOT in the build. Feb 19, 2016
junit-trait-runner [GSCOLLECT-1675] Update version number to 7.0.4-SNAPSHOT in the build. Feb 19, 2016
memory-tests [GSCOLLECT-1675] Update version number to 7.0.4-SNAPSHOT in the build. Feb 19, 2016
performance-tests [GSCOLLECT-1675] Update version number to 7.0.4-SNAPSHOT in the build. Feb 19, 2016
scala-unit-tests [GSCOLLECT-1675] Update version number to 7.0.4-SNAPSHOT in the build. Feb 19, 2016
serialization-tests [GSCOLLECT-1675] Update version number to 7.0.4-SNAPSHOT in the build. Feb 19, 2016
unit-tests-java8 [GSCOLLECT-1675] Update version number to 7.0.4-SNAPSHOT in the build. Feb 19, 2016
unit-tests [GSCOLLECT-1675] Update version number to 7.0.4-SNAPSHOT in the build. Feb 19, 2016
.classpath [GSCOLLECT-35] Initial import. Jan 5, 2012
.gitignore [GSCOLLECT-625] Add .gitignore file. Feb 9, 2012
.project [GSCOLLECT-35] Initial import. Jan 5, 2012
.travis.yml [GSCOLLECT-1584] Configure Travis CI build. Mar 1, 2015
LICENSE-2.0.txt [GSCOLLECT-35] Initial import. Jan 5, 2012
NOTICE [GSCOLLECT-1671] Remove unnecessary references from NOTICE file. Feb 17, 2016
README.md [GSCOLLECT-1668] Update README.md to navigate users to Eclipse Collec… Feb 15, 2016
build.xml [GSCOLLECT-1325] Change test modules to use Java 8 and replace anonym… Mar 8, 2014
checkstyle-configuration.xml [GSCOLLECT-1653] Update versions of dependencies. Oct 6, 2015
checkstyle-suppressions.xml [GSCOLLECT-1653] Update versions of dependencies. Oct 6, 2015
collections-parent.iml [GSCOLLECT-1278] Update versions of dependencies. Feb 26, 2014
common-build.xml [GSCOLLECT-42] Configure deployment to Maven Central. Sep 25, 2013
deploy.properties [GSCOLLECT-1674] Update version number to 7.0.3 in the build. Feb 19, 2016
findbugs-exclude.xml [GSCOLLECT-1212] Implement ObjectPrimitiveHashMapWithHashingStrategy. Oct 2, 2015
java.header [GSCOLLECT-898] Change the CheckStyle header regular expression to al… Mar 22, 2013
pom-template [GSCOLLECT-42] Configure deployment to Maven Central. Sep 26, 2013
pom.xml [GSCOLLECT-1675] Update version number to 7.0.4-SNAPSHOT in the build. Feb 19, 2016
version.properties [GSCOLLECT-1594] Update versions of dependencies. Mar 25, 2015

README.md

GS Collections is now Eclipse Collections

We are pleased to announce that GS Collections has been migrated to the Eclipse Foundation, re-branded as Eclipse Collections.

Eclipse Collections 7.0 has the exact same feature set as GS Collections 7.0.

Going forward, any new features will be developed in Eclipse Collections. We will only port critical bug fixes to GS Collections. To support smooth migration for users, we implemented a conversion application gsc-ec-converter. Please plan your migration accordingly from GS Collections to Eclipse Collections.

GS Collections

GS Collections is a collections framework for Java. It has JDK-compatible List, Set and Map implementations with a rich API and set of utility classes that work with any JDK compatible Collections, Arrays, Maps or Strings. The iteration protocol was inspired by the Smalltalk collection framework. The library modules in GS Collections are compatible with Java 5 (gs-collections-api, gs-collections, and gs-collections-testutils).

Quick Example

GS Collections puts iteration methods on the container types. Lambdas are simulated using anonymous inner classes. Here's a code example that demonstrates the usual style of programming with GS Collections.

MutableList<Person> people = FastList.newListWith(person1, person2, person3);
MutableList<String> sortedLastNames = people.collect(Person.TO_LAST_NAME).sortThis();
System.out.println("Comma separated, sorted last names: " + sortedLastNames.makeString());

Person.TO_LAST_NAME is defined as a constant Function in the Person class.

public static final Function<Person, String> TO_LAST_NAME = new Function<Person, String>()
{
    public String valueOf(Person person)
    {
        return person.lastName;
    }
};

In Java 8, the Function can be replaced with a lambda:

MutableList<String> sortedLastNames = people.collect(person -> person.getLastName()).sortThis();

Or, a method reference:

MutableList<String> sortedLastNames = people.collect(Person::getLastName).sortThis();

Why GS Collections?

  • Improves readability and reduces duplication of iteration code (enforces DRY/OAOO)
  • Implements several, high-level iteration patterns (select, reject, collect, inject into, etc.) on "humane" container interfaces which are extensions of the JDK interfaces
  • Provides a consistent mechanism for iterating over Collections, Arrays, Maps, and Strings
  • Provides replacements for ArrayList, HashSet, and HashMap optimized for performance and memory usage
  • Performs more "behind-the-scene" optimizations in utility classes
  • Encapsulates a lot of the structural complexity of parallel iteration and lazy evaluation
  • Adds new containers including Bag, Interval, Multimap, BiMap, and immutable versions of all types
  • Has been under active development since 2005 and is a mature library

Documentation

The best way to learn about GS Collections is to dive into the code kata. The kata is a fun way to learn idiomatic GS Collections usage and hone your skills through practice. Please refer to the wiki for more details.

For more comprehensive documentation, take a look at the Reference Guide.

Contributions

We currently do all development in an internal Subversion repository and are not prepared to take external contributions. However, we watch the issue tracker for bug reports and feature requests.

FAQ

Why is Goldman Sachs open-sourcing GS Collections?

  • We believe that GS Collections offers a significant advantage over existing solutions. We hope others will benefit from it.
  • We believe in the power of the technical community to help improve GS Collections.
  • Technology is a huge part of what we do at Goldman Sachs. GS Collections exemplifies our commitment to technology.
  • We use open source software in many of our operations. We have benefited from the work of others and we'd like to give something back.

Does Goldman Sachs use GS Collections?

Yes, we use GS Collections in many of our internal applications.

Acquiring GS Collections

Download

Maven

<dependency>
  <groupId>com.goldmansachs</groupId>
  <artifactId>gs-collections-api</artifactId>
  <version>7.0.0</version>
</dependency>

<dependency>
  <groupId>com.goldmansachs</groupId>
  <artifactId>gs-collections</artifactId>
  <version>7.0.0</version>
</dependency>

<dependency>
  <groupId>com.goldmansachs</groupId>
  <artifactId>gs-collections-testutils</artifactId>
  <version>7.0.0</version>
  <scope>test</scope>
</dependency>

<dependency>
  <groupId>com.goldmansachs</groupId>
  <artifactId>gs-collections-forkjoin</artifactId>
  <version>7.0.0</version>
</dependency>

Gradle

compile 'com.goldmansachs:gs-collections-api:7.0.0'
compile 'com.goldmansachs:gs-collections:7.0.0'
testCompile 'com.goldmansachs:gs-collections-testutils:7.0.0'
compile 'com.goldmansachs:gs-collections-forkjoin:7.0.0'

Ivy

<dependency org="com.goldmansachs" name="gs-collections-api" rev="7.0.0" />
<dependency org="com.goldmansachs" name="gs-collections" rev="7.0.0" />
<dependency org="com.goldmansachs" name="gs-collections-testutils" rev="7.0.0" />
<dependency org="com.goldmansachs" name="gs-collections-forkjoin" rev="7.0.0"/>