code: package it.unibz.inf.ontop.spec.ontology;
  
  /*
   * #%L
   * ontop-reformulation-core
   * %%
   * Copyright (C) 2009 - 2014 Free University of Bozen-Bolzano
   * %%
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   * 
   *      http://www.apache.org/licenses/LICENSE-2.0
   * 
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   * #L%
   */
  
  
  import com.google.common.collect.ImmutableSet;
  
  import java.util.Iterator;
  import java.util.stream.Stream;
  
  public class Equivalences<T> implements Iterable<T> {
  	
  	final private ImmutableSet<T> members;
  	// two mutables
  	private T representative;
  	private boolean isIndexed;
  
  	public Equivalences(ImmutableSet<T> members) {
  		this(members, null, false);
  	}
  	
  	public Equivalences(ImmutableSet<T> members, T representative, boolean isIndexed) {
  		this.members = members;
  		this.representative = representative;
  		this.isIndexed = isIndexed;
  	}
  	
  	public void setRepresentative(T representative) {
  		this.representative = representative;
  	}
  	
  	public T getRepresentative() {
  		return representative;
  	}
  	
  	public boolean isIndexed() {
  		return isIndexed;
  	}
  	
  	public void setIndexed() {
  		isIndexed = true;
  	}
  	
  	public ImmutableSet<T> getMembers() {
  		return members;
  	}
  
  	public Stream<T> stream() { return members.stream(); }
  	
  	public int size() {
  		return members.size();
  	}
  	
  	public boolean contains(T v) {
  		return members.contains(v);
  	}
  
  	@Override
  	public Iterator<T> iterator() {
  		return members.iterator();
  	}
  	
  	@Override
  	public boolean equals(Object o) {
  		if (o instanceof Equivalences<?>) {
  			@SuppressWarnings("unchecked")
  			Equivalences<T> other = (Equivalences<T>)o;
  			return this.members.equals(other.members);
  		}
  		return false;
  	}
  	
  	@Override 
  	public int hashCode() {
  		return members.hashCode();
  	}
  	
  	@Override
  	public String toString() {
  		return "C[" + (isIndexed ? "SI, " : "") + representative + ": " + members + "]";
  	}
  }
  