code: //==============================================================================
  //	
  //	Copyright (c) 2002-
  //	Authors:
  //	* Dave Parker <david.parker@comlab.ox.ac.uk> (University of Oxford)
  //	
  //------------------------------------------------------------------------------
  //	
  //	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 pta;
  
  import java.io.IOException;
  import java.io.Writer;
  import java.util.*;
  
  import prism.PrismException;
  
  public class Edge
  {
  	// Parent transition;
  	private Transition parent;
  	// Probability
  	private double prob;
  	// Destination location
  	private int dest;
  	// Resets
  	private HashMap<Integer, Integer> resets;
  
  	/**
  	 * Create an empty edge.
  	 * @param parent Parent transition
  	 * @param prob Probability
  	 * @param dest destination location
  	 */
  	public Edge(Transition parent, double prob, int dest)
  	{
  		this.parent = parent;
  		this.prob = prob;
  		this.dest = dest;
  		resets = new HashMap<Integer, Integer>();
  	}
  
  	/**
  	 * Copy constructor.
  	 */
  	public Edge(Edge edge)
  	{
  		this(edge.parent, edge.prob, edge.dest);
  		for (Map.Entry<Integer, Integer> e : edge.resets.entrySet()) {
  			addReset(e.getKey(), e.getValue());
  		}
  	}
  	
  	public void setProb(double prob)
  	{
  		this.prob = prob;
  	}
  
  	public void setDestination(int dest)
  	{
  		this.dest = dest;
  	}
  
  	public void setParent(Transition parent)
  	{
  		this.parent = parent;
  	}
  
  	public void addReset(int clock)
  	{
  		addReset(clock, 0);
  	}
  
  	public void addReset(int clock, int val)
  	{
  		resets.put(clock, val);
  	}
  
  	public Transition getParent()
  	{
  		return parent;
  	}
  
  	public int getDestination()
  	{
  		return dest;
  	}
  
  	public double getProbability()
  	{
  		return prob;
  	}
  
  	public Iterable<Map.Entry<Integer, Integer>> getResets()
  	{
  		return resets.entrySet();
  	}
  
  	/**
  	 * Perform some basic syntactic checks.
  	 */
  	public void check() throws PrismException
  	{
  	}
  
  	public String toString()
  	{
  		boolean first = true;
  		String s = "";
  		s += prob + " : {";
  		for (Map.Entry<Integer, Integer> e : resets.entrySet()) {
  			if (first)
  				first = false;
  			else
  				s += ",";
  			s += parent.getParent().getClockName(e.getKey());
  			s += "=" + e.getValue();
  		}
  		s += "}" + parent.getParent().getLocationName(dest);
  		return s;
  	}
  
  	public void writeToDesFile(Writer out, String actionPrefix, Iterable<Constraint> guard) throws PrismException,
  			IOException
  	{
  		boolean first;
  		PTA pta = parent.getParent();
  		out.write("\t" + actionPrefix + "tran  ");
  		out.write(pta.getLocationName(dest).toString().replace(':', '_') + "; ");
  		out.write(Constraint.toStringList(pta, guard));
  		out.write("; ");
  		first = true;
  		for (Map.Entry<Integer, Integer> e : resets.entrySet()) {
  			if (first)
  				first = false;
  			else
  				out.write(",");
  			out.write(pta.getClockName(e.getKey()) + "=" + e.getValue());
  		}
  		if (first)
  			out.write("null");
  		out.write("; " + prob + "\n");
  	}
  }
  