Support generating delegate classes

andriy-dmytruk commented 2 weeks ago

Feature description

The change allows generating classes implementing delegation/wrapper pattern.

An example of generated class would be:

public abstract class WorkerDelegate implements Worker {
  Worker delegatee;

  WorkerDelegate(Worker delegatee) {
    this.delegatee = delegatee;
  }

  @Override
  public double tasksPerDay() {
    return this.delegatee.tasksPerDay();
  }

  @Override
  public String name() {
    return this.delegatee.name();
  }

  @Override
  public boolean canComplete(List<String> tasks) {
    return this.delegatee.canComplete(tasks);
  }

  @Override
  public List<String> competencies() {
    return this.delegatee.competencies();
  }
}

User would then extend it to customize only some of the behavior, like:

public class OvertimeWorker extends WorkerDelegate {

    OvertimeWorker(Worker delegatee) {
        super(delegatee);
    }

    @Override
    public double tasksPerDay() {
        return super.tasksPerDay() * 1.2;
    }
}

For Kotlin:

public abstract class WorkerDelegate : Worker {
  public var delegatee: Worker

  public constructor(delegatee: Worker) {
    this. delegatee = delegatee
  }

  public override fun tasksPerDay(): Double {
    return this. delegatee.tasksPerDay()
  }

  public override fun name(): String {
    return this. delegatee.name()
  }

  public override fun canComplete(tasks: List<String>): Boolean {
    return this. delegatee.canComplete(tasks)
  }

  public override fun competencies(): List<String> {
    return this. delegatee.competencies()
  }
}