Pipe multiple functional calls in java. In the example the operations are on Integers.

FunctionalPipe.java

// This code is licensed under the terms of the APACHE 2 License (https://www.apache.org/licenses/LICENSE-2.0.html)
// Copyright (C) 2023 Aoun Abel [email protected]

public class FunctionalPipe {
    public static <T> T pipe(T value,
                             Function<? super T, ? extends T>... functions) {
        Function<T, T> accumulator = Function.identity();
        for (Function<? super T, ? extends T> function : functions)
            accumulator = accumulator.compose(function);
        return accumulator.apply(value);
    }
}

public class FunctionalPipeTest {
  
    @Test
    public void pipe_shouldWork() {
        Function<Integer, Integer> increment = (a) -> a + 1;
        Integer res = FunctionalPipe.pipe(
            1,
            increment,
            add(2)
        );
        Assert.assertEquals(new Integer(4), res);
    }
    
    private Function<Integer, Integer> add(Integer integer){
        Function<Integer, Function<Integer, Integer>> addf = a -> b -> a + b;
        return addf.apply(integer);
    }

}