RxPartialApplication

RxPartialApplication is a library to allow partial application on RxJava function primitives.

For the RxJava 2.X version please go to RxPartialApplication2.

Usage

RxPartialApplication contains two classes, RxPartialAction and RxPartialFunc. Each contains a set of apply() (apply parameters from left to right) and applyEnd() (apply parameters from right to left) methods to do partial application from any ActionN and FuncN to any type of a lower arity. For example, you can partially apply a Func6 object with 3 prefilled parameters to obtain a Func3 object to be reused.

Function to multiply numbers by 100:

Func1<Integer, Integer> multiplyBy100 = RxPartialFunc.apply((int first, int second) -> { return first * second; }, 100);
int result = multiplyBy100.call(5); // result == 500

Single parameter applicator:

Action1<String> salutator = RxPartialAction.apply(applicator(), (String parameter) -> { System.out.println("Hello, " + parameter); } );
salutator.call("pakoito"); // prints "Hello, pakoito"
Action1<Integer> duplicator = RxPartialFunc.apply(applicator(), (int parameter) -> { System.out.println("Double of parameter is " + 2 * parameter); } );
duplicator.call(2); // prints "Double of parameter is 4"

...

public static <T> Action2<Action1<T>, T> applicator() {
    return (Action1<T> action, T parameter) -> { action.call(parameter); };
}

Filter only myself:

Func1<Object, Boolean> isMe = RxPartialFunc.apply(equalsFilter(), myUser);
updatesFromDatabaseObservable().filter(isMe).map(toUser()).subscribe(/* ... */);

...

public static <T, U> Func2<T, U, Boolean> equalsFilter() {
    return (T first, U second) -> { return first.equals(second); };
}

You can also partially apply from the last parameter using applyEnd()

Func1<String, Observable<String>>> requestForUrl = 
        RxPartialFunc.applyEnd(this::doNetworkRequest(), localDataStorage, ServerInfo.default(), RetrofitRequest.getInstance());

requestForUrl.call("http://www.mycompany.com/api/users").subscribe(/* ... */);

Observable<String> doNetworkRequest(String url, DataStorage storage, ServerInformation server, HttpClient client){
  ...
}

Distribution

Add as a dependency to your build.gradle

repositories {
    ...
    maven { url "https://jitpack.io" }
    ...
}
    
dependencies {
    ...
    compile 'com.github.pakoito:RxPartialApplication:1.1.0'
    ...
}

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>RxPartialApplication</artifactId>
    <version>1.1.0</version>
</dependency>

License

Copyright (c) pakoito 2016

The Apache Software License, Version 2.0

See LICENSE.md