RxTuples2

RxTuples2 is a library to smooth RxJava2 usage by adding simple Tuple creation functions.

For the RxJava 1.X version, please go to RxTuples.

Rationale

Quite often when using RxJava you find the need to forward a value alongside the result of an operation, combine several values, or simply adding an external value to the current internal state of the chain. For this you either create ad-hoc types that may only be used locally, which is inefficient.

Other languages have the concept of a Tuple built into them, which is an in-place list of values. Lots of Java libraries implement their own concept of Tuple, being a Pair, a Point, or VecX types. This library uses javatuples in an attempt to unify them. Javatuples are all "typesafe, immutable, iterable, serializable, comparable" classes ranging from 1 to 10 elements.

Usage

RxTuples come as lazily evaluated FunctionN and its main use case is alongside the combineLatest(), withLatestFrom(), zip(), and zipWith() operators.

Zip a list element into a pair with their position:

Observable.zip(Observable.from(myStringList), Observable.range(0, myStringList.size()), 
               RxTuples.<String, Integer>toPair());

Merge the value of several hot observables:

Observable.combineLatest(networkSubject(), bluetoothSubject(), compassSubject(), 
                         RxTuples.<NetworkStatus, BluetoothState, CompassPosition>toTriplet());

Get the previous element from a sequence alongside the current one:

Observable.zip(compassSubject(), compassSubject().skip(1), 
               RxTuples.<CompassPosition, CompassPosition>toPair());

or more complicated cases

Observable.just(Quintet.with(1, 2, 3, 4, 5))
          .zipWith(
                Observable.just(Triplet.with(6, 7, 8)),
                RxTuples.<Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer> toOctetFromQuintet());

Distribution

Add as a dependency to your build.gradle

repositories {
    ...
    maven { url "https://jitpack.io" }
    ...
}

dependencies {
    ...
    compile 'com.github.pakoito:RxTuples2:1.0.0'
    ...
}

or to your pom.xml

<repositories>
    <repository>
        <id>jitpack.io</id>
        <url>https://jitpack.io</url>
    </repository>
</repositories>

<dependency>
    <groupId>com.github.pakoito</groupId>
    <artifactId>RxTuples2</artifactId>
    <version>1.0.0</version>
</dependency>

License

Copyright (c) pakoito 2017

The Apache Software License, Version 2.0

See LICENSE.md