kotlinx-bimap

A bimap (bidirectional map) implementation for Kotlin.

Prerequisites

• JDK 1.6 or higher

Interfaces and implementations

This library provides interfaces for read-only/mutable bimap:

Interface	Bases	Implementations
BiMap	Map	emptyBiMap, biMapOf, toBiMap
MutableBiMap	MutableMap, BiMap	mutableBiMapOf, toMutableBiMap

Operations

Create read-only bimap

• Create an empty read-only bimap:

  val newBiMap = emptyBiMap()

• Create a new read-only bimap from pairs:

  val newBiMap = biMapOf(1 to "1", 2 to "2", 3 to "3")

• Create a new read-only bimap from map:

  val newBiMap = mapOf(1 to "1", 2 to "2", 3 to "3").toBiMap()

Create mutable bimap

• Create an empty mutable bimap:

  val newBiMap = mutableBiMapOf()

• Create a new mutable bimap from pairs:

  val newBiMap = mutableBiMapOf(1 to "1", 2 to "2", 3 to "3")

• Create a new mutable bimap from map:

  val newBiMap = mapOf(1 to "1", 2 to "2", 3 to "3").toMutableBiMap()

Query bimap

• Bimap support all operations of map:

  val biMap = biMapOf(1 to "1", 2 to "2", 3 to "3")
  biMap.size // 3
  biMap.isEmpty() // false
  biMap.values // ["1", "2", "3"]
  biMap[1] // "1"
  biMap.containsKey(4) // false

• Get the inverse view of bimap:

  val biMap = biMapOf(1 to "1", 2 to "2", 3 to "3")
  val inverseBiMap = biMap.inverse
  inverseBiMap.values // [1, 2, 3]

Mutate mutable bimap

Mutable bimap support all operations of mutable map:

val mutableBiMap = mutableBiMapOf(1 to "1", 2 to "2", 3 to "3")
mutableBiMap[3] = "4"
mutableBiMap.remove(1)
mutableBiMap.clear()

When using put operation (i.e., mutableBiMap[3] = "4"), the bimap throws IllegalArgumentException if the given value is already bound to a different key in it. The bimap will remain unmodified in this event. To avoid this exception, call forcePut instead:

mutableBiMap.forcePut(4, "2")

The forcePut operation will silently remove any existing entry with the value before proceeding with the put operation.

Interoperability with Guava bimap

• Views a mutable bimap as a Guava bimap:

  val mutableBiMap = mutableBiMapOf(1 to "1", 2 to "2", 3 to "3")
  val guavaBiMap = mutableBiMap.asGuavaBiMap()

• Views a Guava bimap as a mutable bimap:

  val guavaBiMap = HashBiMap.create(mapOf(1 to "1", 2 to "2", 3 to "3"))
  val mutableBiMap = guavaBiMap.asMutableBiMap()

Using in your projects

This library has been published to Maven Central, JCenter and JitPack.

Maven

<dependency>
  <groupId>com.uchuhimo</groupId>
  <artifactId>kotlinx-bimap</artifactId>
  <version>1.2</version>
</dependency>

Gradle

compile 'com.uchuhimo:kotlinx-bimap:1.2'

Gradle Kotlin DSL

compile(group = "com.uchuhimo", name = "kotlinx-bimap", version = "1.2")

Building from source

Build library with Gradle using the following command:

gradlew clean assemble

Test library with Gradle using the following command:

gradlew clean test

Since Gradle has excellent incremental build support, you can usually omit executing the clean task.

Install library in a local Maven repository for consumption in other projects via the following command:

gradlew clean install

License

© uchuhimo, 2017-2018. Licensed under an Apache 2.0 license.