Tuple: Add functional mappers to tuples

[minborg]

  map(toTuple(Hare::getId,Hare::getName, Hare::getAge));

Similar to toMap() collector extractors

[minborg]

    interface TupleMapper<T> {

        Function<T, ?> getMapper(int index);
    }

    interface Tuple1Mapper<T, T0> extends TupleMapper<T>, Function<T, Tuple1<T0>> {
    }

    interface Tuple2Mapper<T, T0, T1> extends TupleMapper<T>, Function<T, Tuple2<T0, T1>> {
    }

    static class Tuple1MapperImpl<T, T0> implements Tuple1Mapper<T, T0> {

        private final Function<T, T0> mapper0;

        public Tuple1MapperImpl(Function<T, T0> mapper0) {
            this.mapper0 = requireNonNull(mapper0);
        }

        @Override
        public Tuple1<T0> apply(T t) {
            return Tuples.of(mapper0.apply(t));
        }

        @Override
        public Function<T, ?> getMapper(int index) {
            if (index == 0) {
                return mapper0;
            };
            throw new IllegalArgumentException();
        }

    }

    private <T, T0> Tuple1Mapper<T, T0> tupleMapper(Function<T, T0> mapper0) {
        return new Tuple1MapperImpl<>(mapper0);
        //return (T t) -> Tuples.of(mapper0.apply(t));
    }

    private <T, T0, T1> Function<T, Tuple2<T0, T1>> tupleMapper(Function<T, T0> mapper0, Function<T, T1> mapper1) {
        return (T t) -> Tuples.of(mapper0.apply(t), mapper1.apply(t));
    }