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 explicit;
  
  import java.io.FileWriter;
  import java.io.IOException;
  import java.util.AbstractMap;
  import java.util.Iterator;
  import java.util.Map;
  import java.util.TreeMap;
  import java.util.Map.Entry;
  
  import explicit.graphviz.Decorator;
  import prism.ModelType;
  import prism.Pair;
  import prism.PrismException;
  import prism.PrismLog;
  import prism.PrismUtils;
  
  /**
   * Base class for explicit-state representations of a DTMC.
   */
  public abstract class DTMCExplicit extends ModelExplicit implements DTMC
  {
  	// Accessors (for Model)
  	
  	@Override
  	public ModelType getModelType()
  	{
  		return ModelType.DTMC;
  	}
  
  	@Override
  	public void exportToPrismExplicitTra(PrismLog out)
  	{
  		int i;
  		TreeMap<Integer, Pair<Double, Object>> sorted;
  		// Output transitions to .tra file
  		out.print(numStates + " " + getNumTransitions() + "\n");
  		sorted = new TreeMap<Integer, Pair<Double, Object>>();
  		for (i = 0; i < numStates; i++) {
  			// Extract transitions and sort by destination state index (to match PRISM-exported files)
  			Iterator<Map.Entry<Integer,Pair<Double, Object>>> iter = getTransitionsAndActionsIterator(i);
  			while (iter.hasNext()) {
  				Map.Entry<Integer, Pair<Double, Object>> e = iter.next();
  				sorted.put(e.getKey(), e.getValue());
  			}
  			// Print out (sorted) transitions
  			for (Map.Entry<Integer, Pair<Double, Object>> e : sorted.entrySet()) {
  				// Note use of PrismUtils.formatDouble to match PRISM-exported files
  				out.print(i + " " + e.getKey() + " " + PrismUtils.formatDouble(e.getValue().first));
  				Object action = e.getValue().second; 
  				if (action != null && !"".equals(action))
  					out.print(" " + action);
  				out.print("\n");
  			}
  			sorted.clear();
  		}
  	}
  
  	@Override
  	public void exportTransitionsToDotFile(int i, PrismLog out, Iterable<explicit.graphviz.Decorator> decorators)
  	{
  		Iterator<Map.Entry<Integer, Double>> iter = getTransitionsIterator(i);
  		while (iter.hasNext()) {
  			Map.Entry<Integer, Double> e = iter.next();
  			out.print(i + " -> " + e.getKey());
  
  			explicit.graphviz.Decoration d = new explicit.graphviz.Decoration();
  			d.setLabel(e.getValue().toString());
  			if (decorators != null) {
  				for (Decorator decorator : decorators) {
  					d = decorator.decorateProbability(i, e.getKey(), e.getValue(), d);
  				}
  			}
  
  			out.println(d.toString());
  		}
  	}
  
  	@Override
  	public void exportToPrismLanguage(String filename) throws PrismException
  	{
  		int i;
  		boolean first;
  		FileWriter out;
  		TreeMap<Integer, Double> sorted;
  		try {
  			// Output transitions to PRISM language file
  			out = new FileWriter(filename);
  			out.write(getModelType().keyword() + "\n");
  			out.write("module M\nx : [0.." + (numStates - 1) + "];\n");
  			sorted = new TreeMap<Integer, Double>();
  			for (i = 0; i < numStates; i++) {
  				// Extract transitions and sort by destination state index (to match PRISM-exported files)
  				Iterator<Map.Entry<Integer, Double>> iter = getTransitionsIterator(i);
  				while (iter.hasNext()) {
  					Map.Entry<Integer, Double> e = iter.next();
  					sorted.put(e.getKey(), e.getValue());
  				}
  				// Print out (sorted) transitions
  				out.write("[]x=" + i + "->");
  				first = true;
  				for (Map.Entry<Integer, Double> e : sorted.entrySet()) {
  					if (first)
  						first = false;
  					else
  						out.write("+");
  					// Note use of PrismUtils.formatDouble to match PRISM-exported files
  					out.write(PrismUtils.formatDouble(e.getValue()) + ":(x'=" + e.getKey() + ")");
  				}
  				out.write(";\n");
  				sorted.clear();
  			}
  			out.write("endmodule\n");
  			out.close();
  		} catch (IOException e) {
  			throw new PrismException("Could not export " + getModelType() + " to file \"" + filename + "\"" + e);
  		}
  	}
  	
  	// Accessors (for DTMC)
  	
  	@Override
  	public Iterator<Entry<Integer, Pair<Double, Object>>> getTransitionsAndActionsIterator(int s)
  	{
  		// Default implementation: extend iterator, setting all actions to null
  		return new AddDefaultActionToTransitionsIterator(getTransitionsIterator(s), null);
  	}
  
  	public class AddDefaultActionToTransitionsIterator implements Iterator<Map.Entry<Integer, Pair<Double, Object>>>
  	{
  		private Iterator<Entry<Integer, Double>> transIter;
  		private Object defaultAction;
  		private Entry<Integer, Double> next;
  
  		public AddDefaultActionToTransitionsIterator(Iterator<Entry<Integer, Double>> transIter, Object defaultAction)
  		{
  			this.transIter = transIter;
  			this.defaultAction = defaultAction;
  		}
  
  		@Override
  		public Entry<Integer, Pair<Double, Object>> next()
  		{
  			next = transIter.next();
  			final Integer state = next.getKey();
  			final Double probability = next.getValue();
  			return new AbstractMap.SimpleImmutableEntry<>(state, new Pair<>(probability, defaultAction));
  		}
  
  		@Override
  		public boolean hasNext()
  		{
  			return transIter.hasNext();
  		}
  
  		@Override
  		public void remove()
  		{
  			// Do nothing: read-only
  		}
  	}
  }
  