194. Building a dynamic predicate for a custom model

Let’s consider the Car model and a List<Car> denoted as cars:

public class Car {
  private final String brand;
  private final String fuel;
  private final int horsepower;
  ...
}

Also, let’s assume that we need to dynamically produce a wide range of predicates that apply the operators <, >, <=, >=, !=, and == to the horsepower field. It will be cumbersome to hardcode such predicates, so we have to come up with a solution that can build, on the fly, any predicate that involves this field, and one of the comparison operators listed here.

There are a few approaches to accomplish this goal, and one of them is to use a Java enum. We have a fixed list of operators that can be coded as enum elements, as follows:

enum PredicateBuilder {
  GT((t, u) -> t > u),
  LT((t, u) -> t < u),
  GE((t, u) -> t >= u),
  LE((t, u) -> t <= u),
  EQ((t, u) -> t.intValue() == u...