Λrrow is a library for Typed Functional Programming in Kotlin.
Arrow aims to provide a lingua franca of interfaces
and abstractions across Kotlin libraries. For this, it includes the most popular data types such
as Option
, Either
, Validated
etc and functional operators such as traverse
and computation
blocks to empower users to write pure FP apps and libraries built atop higher order abstractions.
Use the list below to learn more about Λrrow's main features.
If you have a blog post, talk, or upcoming event on Arrow, please considering opening an issue or PR to add to the collection over at the Arrow Media repo.
The next version of Arrow is in active development. If you want to try it, you need to add the following repository in your build file:
maven("https://oss.sonatype.org/content/repositories/snapshots")
and depend on the 2.0.0-SNAPSHOT
version of the desired library.
Arrow is an inclusive community powered by awesome individuals like you. As an actively growing ecosystem, Arrow and its associated libraries and toolsets are in need of new contributors! We have issues suited for all levels, from entry to advanced, and our maintainers are happy to provide 1:1 mentoring. All are welcome in Arrow.
If you’re looking to contribute, have questions, or want to keep up-to-date about what’s happening, please follow us here and say hello!
Find more details in CONTRIBUTING.
Make sure to have the latest version of JDK 1.8 (or higher) installed.
Arrow supports Android starting on API 21 and up.
In your project's root build.gradle
, append this repository to your list:
allprojects {
repositories {
mavenCentral()
}
}
Add the dependencies into the project's build.gradle
:
def arrow_version = "1.0.1"
dependencies {
implementation "io.arrow-kt:arrow-core:$arrow_version"
}
apply plugin: 'kotlin-kapt'
def arrow_version = "1.0.1"
dependencies {
implementation "io.arrow-kt:arrow-optics:$arrow_version"
kapt "io.arrow-kt:arrow-meta:$arrow_version"
}
def arrow_version = "1.0.1"
dependencies {
implementation "io.arrow-kt:arrow-fx-coroutines:$arrow_version"
}
To avoid specifying the Arrow version for every dependency, a BOM file is available:
implementation platform("io.arrow-kt:arrow-stack:$arrow_version")
implementation "io.arrow-kt:arrow-core"
implementation "io.arrow-kt:arrow-fx-coroutines"
...
Make sure to have at least the latest version of JDK 1.8 installed. Add to your pom.xml
file the
following properties:
<properties>
<kotlin.version>1.5.31</kotlin.version>
<arrow.version>1.0.1</arrow.version>
</properties>
Add the dependencies that you want to use:
<dependency>
<groupId>io.arrow-kt</groupId>
<artifactId>arrow-core</artifactId>
<version>${arrow.version}</version>
</dependency>
For the Optics DSL, enable annotation processing using Kotlin plugin:
<plugin>
<groupId>org.jetbrains.kotlin</groupId>
<artifactId>kotlin-maven-plugin</artifactId>
<version>${kotlin.version}</version>
<executions>
<execution>
<id>kapt</id>
<goals>
<goal>kapt</goal>
</goals>
<configuration>
<sourceDirs>
<sourceDir>src/main/kotlin</sourceDir>
</sourceDirs>
<annotationProcessorPaths>
<annotationProcessorPath>
<groupId>io.arrow-kt</groupId>
<artifactId>arrow-meta</artifactId>
<version>${arrow.version}</version>
</annotationProcessorPath>
</annotationProcessorPaths>
</configuration>
</execution>
<execution>
<id>compile</id>
<phase>compile</phase>
<goals>
<goal>compile</goal>
</goals>
<configuration>
<sourceDirs>
<sourceDir>src/main/kotlin</sourceDir>
</sourceDirs>
</configuration>
</execution>
<execution>
<id>test-compile</id>
<phase>test-compile</phase>
<goals>
<goal>test-compile</goal>
</goals>
</execution>
</executions>
</plugin>
To avoid specifying the Arrow version for every dependency, a BOM file is available:
<dependencyManagement>
<dependencies>
<dependency>
<groupId>io.arrow-kt</groupId>
<artifactId>arrow-stack</artifactId>
<version>${arrow.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<dependencies>
...
</dependencies>
If you want to try the latest features, replace 1.0.1
with 1.0.2-SNAPSHOT
and add this
repository:
allprojects {
repositories {
...
maven { url "https://oss.sonatype.org/content/repositories/snapshots/" }
}
}
Copyright (C) 2017 The Λrrow Authors
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.