Some examples using FunctionalJava

FunctionalJavaExample.java

package com.jooyunghan;

import fj.P2;
import fj.data.List;
import fj.data.Stream;

import static fj.P.p;
import static fj.Show.*;
import static fj.data.List.list;
import static fj.data.Stream.iterate;
import static fj.data.Stream.stream;

/**
 * User: jooyunghan
 * Date: 5/13/15 4:54 AM
 */
public class FunctionalJavaExample {
    public static void main(String[] args) {
        final List<Integer> a = list(1, 2, 3).map(i -> i + 42);
        listShow(intShow).println(a); // [43,44,45]

        // combined into a single line
        listShow(intShow).println(list(1, 2, 3).map(i -> i + 42)); // [43,44,45]

        List<Integer> mappedList = list(1, 2, 3).map(n -> {
            System.out.println(n);
            return n + 1;
        });

        Stream<Integer> mappedStream = stream(1, 2, 3).map(n -> {
            System.out.println(n);
            return n + 1;
        });

        Stream<Integer> fibonacci = iterate(p2 -> p(p2._2(), p2._1() + p2._2()), p(0, 1)).map(P2.__1());
        streamShow(intShow).println(fibonacci.take(10));
        fibonacci.take(10).foreachDoEffect(System.out::println);

        int sum = fibonacci.takeWhile(n -> n < 4000000).filter(n -> n % 2 == 0).foldLeft1((x, y) -> x + y);
        System.out.println(sum);
    }
}