XSet - Extended Sets for Java

Contents

• Overview
• Usage
  • XSet
• Build
• Release
• License

Overview

This is a Java library for sets and complementary sets.

Usage

XSet

This class is an extension of a finite set. It can hold both finite sets and those inifite ones that can be represented as a complement of finite sets.

The standard set operations are supported: contains, containsAll, containsAny, complement, subtraction, instersection and union. XSet is a generic type.

The implementation maintains a finite Set of items and a boolean flag complementary. The items should hold only a given type of elements - according to the generic type (e.g. "String" or "Long"). The items cannot hold null elements.

The XSet cannot directly implement java.util.Collection, because the method java.util.Collection#contains(Object) is not type-safe and we cannot implement such method here. Instead of that we implement method with the same name, but taking as the parameter only objects of the given type.

This class is immutable - once created its content cannot be changed. It also means that this class is thread-safe.

Examples:

XSet<String> weekend = XSet.of("Sat", "Sun");
XSet<String> weekdays = weekend.complement();

assert weekend.contains("Sat");
assert !weekend.contains("Mon");

assert weekdays.contains("Mon");
assert !weekdays.contains("Sat");

assert !weekdays.containsAll("Mon", "Sun");
assert weekdays.containsAny("Mon", "Sun");

assert weekdays.equals(XSet.complementOf("Sat", "Sun"));
assert weekdays.complement().equals(weekend);

assert weekdays.union(weekend).equals(XSet.full());

assert weekdays.intersect(weekend).equals(XSet.empty());

assert weekend.subtract(XSet.of("Sat", "Mon")).equals(XSet.of("Sun"));

Build

Maven is used for building this project:

mvn clean verify

To generate the code coverage report in HTML format, then do the following:

mvn clean verify jacoco:report -Pcoverage

To execute static analysis - PMD, Spotbugs and Checkstyle, then do the following:

mvn pmd:check spotbugs:check checkstyle:check

Release

Release prerequisities:

• install gpg
• ensure you have created and published your GPG key
• ensure you have configured your access for ossrh server in maven settings.xml
• you have committed non-snapshot version to be released

Then build and upload artifacts to staging repository:

mvn clean deploy -Prelease

Verify the staging repository and make the release:

mvn nexus-staging:release -Prelease

License

This project is licensed under MIT License.