io.github.oliviercailloux.j_voting.profiles.analysis.OldFrenchElection Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of j-voting Show documentation

General classes for dealing with social choice theory.

The newest version!

package io.github.oliviercailloux.j_voting.profiles.analysis;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.base.Preconditions;

import io.github.oliviercailloux.j_voting.OldCompletePreferenceImpl;
import io.github.oliviercailloux.j_voting.profiles.ImmutableProfileI;
import io.github.oliviercailloux.j_voting.profiles.ImmutableStrictProfileI;
import io.github.oliviercailloux.j_voting.profiles.StrictProfileI;
import io.github.oliviercailloux.j_voting.profiles.management.StrictProfileBuilder;

/**
 * 
 * This class provides the result of an election, given by the french election
 * system. This means that each voter can only vote for one alternative. This
 * class can provide a result only for strict profiles.
 *
 */
public class OldFrenchElection implements SocialWelfareFunction {

	private static final Logger LOGGER = LoggerFactory.getLogger(OldFrenchElection.class.getName());

	@Override
	public OldCompletePreferenceImpl getSocietyPreference(ImmutableProfileI profile) {
		LOGGER.debug("getSocietyPreference");
		Preconditions.checkNotNull(profile);
		if (!profile.isStrict()) {
			throw new IllegalArgumentException("A french election can only happen with a strict profile.");
		}
		ImmutableStrictProfileI newProf = StrictProfileBuilder.createStrictProfileBuilder((StrictProfileI) profile)
				.createOneAlternativeProfile();
		return Borda.withScores().getSocietyPreference(newProf);
	}
}