io.github.oliviercailloux.grade.OwaAggregator Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of jgradlib Show documentation

The newest version!

package io.github.oliviercailloux.grade;

import static com.google.common.base.Preconditions.checkNotNull;

import com.google.common.base.MoreObjects;
import java.util.List;
import java.util.Objects;
import java.util.stream.Stream;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public final class OwaAggregator implements OwaWeighter {
  @SuppressWarnings("unused")
  private static final Logger LOGGER = LoggerFactory.getLogger(OwaAggregator.class);

  public static OwaAggregator given(List weights) {
    return new OwaAggregator(weights);
  }

  private final List weights;
  private final double sum;

  private OwaAggregator(List weights) {
    this.weights = checkNotNull(weights);
    sum = weights.stream().mapToDouble(w -> w).sum();
  }

  public List weights() {
    return weights;
  }

  @Override
  public Stream weights(int size) {
    return weights.stream().map(w -> w / sum);
  }

  @Override
  public boolean equals(Object o2) {
    if (!(o2 instanceof OwaAggregator)) {
      return false;
    }
    final OwaAggregator t2 = (OwaAggregator) o2;
    return weights.equals(t2.weights);
  }

  @Override
  public int hashCode() {
    return Objects.hash(weights);
  }

  @Override
  public String toString() {
    return MoreObjects.toStringHelper(this).add("weights", weights).toString();
  }
}