/*
    * #%L
    * prolobjectlink-jpi-jtrolog
    * %%
    * Copyright (C) 2012 - 2018 WorkLogic Project
    * %%
    * This program is free software: you can redistribute it and/or modify
    * it under the terms of the GNU Lesser General Public License as
    * published by the Free Software Foundation, either version 2.1 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 Lesser Public License for more details.
   * 
   * You should have received a copy of the GNU General Lesser Public
   * License along with this program.  If not, see
   * <http://www.gnu.org/licenses/lgpl-2.1.html>.
   * #L%
   */
  package jTrolog.parser;
  
  import jTrolog.terms.Term;
  
  import java.util.NoSuchElementException;
  
  /**
   * This class represents an iterator of terms from a string.
   * 
   * @see jTrolog.terms.Term
   */
  @SuppressWarnings({ "rawtypes", "serial" })
  class TermIterator implements java.util.Iterator, java.io.Serializable {
  
  	private Parser parser;
  	private boolean hasNext;
  	private Term next;
  
  	TermIterator(Parser p) {
  		parser = p;
  		next = parser.nextTerm(true);
  		hasNext = (next != null);
  	}
  
  	public Object next() {
  		if (hasNext) {
  			if (next == null)
  				next = parser.nextTerm(true);
  			hasNext = false;
  			Term temp = next;
  			next = null;
  			return temp;
  		} else if (hasNext()) {
  			hasNext = false;
  			Term temp = next;
  			next = null;
  			return temp;
  		}
  		throw new NoSuchElementException();
  	}
  
  	public boolean hasNext() {
  		if (hasNext)
  			return hasNext;
  		next = parser.nextTerm(true);
  		if (next != null)
  			hasNext = true;
  		return hasNext;
  	}
  
  	public void remove() {
  		throw new UnsupportedOperationException();
  	}
  }