code: //==============================================================================
  //	
  //	Copyright (c) 2016-
  //	Authors:
  //	* Joachim Klein <klein@tcs.inf.tu-dresden.de> (TU Dresden)
  //	
  //------------------------------------------------------------------------------
  //	
  //	This file is part of PRISM.
  //	
  //	PRISM 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 2 of the License, or
  //	(at your option) any later version.
  //	
  //	PRISM 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 PRISM; if not, write to the Free Software Foundation,
  //	Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  //	
  //==============================================================================
  
  
  package common.iterable;
  
  import java.util.PrimitiveIterator;
  
  /**
   * An Iterable that returns a Primitive.OfInt iterator for all the integers
   * between two values, first and last (inclusive).
   * If first > last, then the sequence is descending (first, first-1, ..., last+1, last),
   * otherwise it is ascending (first, first+1, ..., last-1, last).
    */
  public class RangeIntIterable implements IterableInt
  {
  	/** The first integer of the sequence */
  	final private int first;
  	/** The last integer of the sequence */
  	final private int last;
  	/** Are we ascending? */
  	final private boolean ascending;
  
  	/**
  	 * Constructor
  	 * @param first the first integer in the sequence
  	 * @param last the last integer in the sequence
  	 */
  	public RangeIntIterable(int first, int last)
  	{
  		this.first = first;
  		this.last = last;
  		ascending = (first <= last);
  	}
  
  	@Override
  	public PrimitiveIterator.OfInt iterator()
  	{
  		return new PrimitiveIterator.OfInt()
  		{
  			int current = first;
  
  			@Override
  			public boolean hasNext()
  			{
  				if (ascending) {
  					return current <= last;
  				} else {
  					return current >= last;
  				}
  			}
  
  			@Override
  			public int nextInt()
  			{
  				if (ascending) {
  					return current++;
  				} else {
  					return current--;
  				}
  			}
  		};
  	}
  }
  