/*
    * #%L
    * prolobjectlink-jpi-jlog
    * %%
    * Copyright (C) 2019 Prolobjectlink Project
    * %%
    * This program is free software: you can redistribute it and/or modify
    * it under the terms of the GNU General Public License as
    * published by the Free Software Foundation, either version 3 of the
   * License, or (at your option) any later version.
   * 
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   * 
   * You should have received a copy of the GNU General Public
   * License along with this program.  If not, see
   * <http://www.gnu.org/licenses/gpl-3.0.html>.
   * #L%
   */
  package io.github.prolobjectlink.prolog.jlog;
  
  import java.util.Enumeration;
  import java.util.Iterator;
  import java.util.NoSuchElementException;
  
  import io.github.prolobjectlink.prolog.AbstractIterator;
  import ubc.cs.JLog.Terms.iTermToObject;
  import ubc.cs.JLog.Terms.jList;
  import ubc.cs.JLog.Terms.jTerm;
  
  /**
   * 
   * @author Jose Zalacain
   * @since 1.0
   */
  final class JLogIterator extends AbstractIterator<jTerm> implements Iterator<jTerm> {
  
  	private Enumeration<?> e;
  
  	JLogIterator(jList list) {
  		if (list != null) {
  			this.e = list.elements(new iTermToObject() {
  				public Object createObjectFromTerm(jTerm term) {
  					return term;
  				}
  			});
  		}
  	}
  
  	public boolean hasNext() {
  		return e != null && e.hasMoreElements();
  	}
  
  	public jTerm next() {
  		if (!hasNext()) {
  			throw new NoSuchElementException();
  		}
  		return e != null ? (jTerm) e.nextElement() : null;
  	}
  
  }