Partial Application in Java

SamplePartialApplication.java

import java.util.function.Function;

import static java.lang.String.format;

class SamplePartialApplication {

    public static void main(String[] args) {

        Fx2<Integer, Integer, Integer> add = (x, y) -> x + y;
        System.out.println(format("Fully applied function of 2 arity result: %s", add.apply(2, 3)));

        Function<Integer, Integer> addTwo = PartialApplication.partial(add, 2);
        System.out.println(format("Partially applied 2 to function of two arity: %s", addTwo.apply(3)));

        Fx3<Integer, Integer, String, String> descriptiveAdd = (x, y, z) -> z + (x + y);
        Fx2<Integer, String, String> firstPartialDescribe = PartialApplication.partial(descriptiveAdd, 2);
        Function<String, String> describe5 = PartialApplication.partial(firstPartialDescribe, 3);;
        System.out.println(describe5.apply("The result is: "));

        Function<String, String> alternativeDescribe5 = PartialApplication.partial(descriptiveAdd, 2, 3);
        System.out.println(alternativeDescribe5.apply("Alternative result is: "));
    }

    /**
     * Function with arity of 2
     * @param <I1> type of first input
     * @param <I2> type of second input
     * @param <O> type of output
     */
    @FunctionalInterface
    public interface Fx2<I1, I2, O> {

        /**
         * Execute this function
         * @param inputOne first input
         * @param inputTwo second input
         * @return output of this function
         */
        O apply(I1 inputOne, I2 inputTwo);
    }

    /**
     * Function with arity of 3
     * @param <I1> type of first input
     * @param <I2> type of second input
     * @param <I3> type of third input
     * @param <O> type of output
     */
    @FunctionalInterface
    public interface Fx3<I1, I2, I3, O> {

        /**
         * Execute this function
         * @param inputOne first input
         * @param inputTwo second input
         * @param inputThree third input
         * @return output of this function
         */
        O apply(I1 inputOne, I2 inputTwo, I3 inputThree);
    }

    public static class PartialApplication {
        public static <I1, I2, O> Function<I2, O> partial(Fx2<I1, I2, O> f, I1 inputOne) {
            return i2 -> f.apply(inputOne, i2);
        }

        public static <I1, I2, I3, O> Function<I3, O> partial(Fx3<I1, I2, I3, O> f, I1 inputOne, I2 inputTwo) {
            return i3 -> f.apply(inputOne, inputTwo, i3);
        }

        public static <I1, I2, I3, O> Fx2<I2, I3, O> partial(Fx3<I1, I2, I3, O> f, I1 inputOne) {
            return (i2, i3) -> f.apply(inputOne, i2, i3);
        }
    }
}