code: /*
   * This file is part of a Java port of the program ltl2dstar
   * (http://www.ltl2dstar.de/) for PRISM (http://www.prismmodelchecker.org/)
   * Copyright (C) 2005-2007 Joachim Klein <j.klein@ltl2dstar.de>
   * Copyright (c) 2007 Carlos Bederian
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as 
   *  published by the Free Software Foundation.
   *
   * 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, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   */
  
  package jltl2dstar;
  
  import jltl2ba.MyBitSet;
  
  /** @file
   * Provides the class SafraTreeTemplate
   */
  
  /**
   * A SafraTreeTemplate consists of a SafraTree and two BitSets,
   * one containing the names of nodes that may be renamed and on
   * containing the names that are not allowed in the tree.
   */
  public class SafraTreeTemplate implements NBA2DAResult<SafraTree> {
  
  	private SafraTree _safraTree;
  	private MyBitSet _renameableNames;
  	private MyBitSet _restrictedNames;
  
  	/**
  	 * Constructor.
  	 * @param safraTree the SafraTree
  	 */
  	public SafraTreeTemplate(SafraTree safraTree)
  	{
  		_safraTree = safraTree;
  		_renameableNames = new MyBitSet();
  		_restrictedNames = new MyBitSet();
  	}
  
  	/** Get the SafraTree */
  	public SafraTree getSafraTree() {return _safraTree;}
  
  	/** Get the SafraTree */
  	public SafraTree getState() {return _safraTree;}
  
  	/** Get the names of nodes that may be renamed. */
  	public MyBitSet renameableNames() {return _renameableNames;}
  
  	/** Get the names that can are not allowed to be used in the Safra tree */
  	public MyBitSet restrictedNames() {return _restrictedNames;}
  
  	/** Set the 'renameable' flag for a name (former flag default: true) */
  	public void setRenameable(int name, boolean flag) { _renameableNames.set(name, flag); }
  
  	/** Get the 'renameable' flag for a name */
  	public boolean isRenameable(int name) { return _renameableNames.get(name); }
  
  	/** Set the 'restricted' flag for a name (former flag default: true) */
  	public void setRestricted(int name, boolean flag) { _restrictedNames.set(name, flag); }
  
  	/** Get the 'restricted' flag for a name */
  	public boolean isRestricted(int name) { return _restrictedNames.get(name); }
  
  
  	/**
  	 * Return true if this tree (taking into account the renameableNames and the restrictedNames) 
  	 * can be renamed to match the SafraTree other.
  	 * Can only be called for trees that are structural_equal!!!
  	 */
  	public boolean matches(SafraTree other) {
  		SafraTreeNode this_root = _safraTree.getRootNode();
  		SafraTreeNode other_root = other.getRootNode();
  
  		if (this_root == null || other_root == null) {
  			assert(this_root == null && other_root == null);
  			return true;
  		}
  
  		return matches(this_root, other_root);
  	}
  
  
  	/**
  	 * Compare two subtrees to see if they match (taking into account the renameableNames
  	 * and the restrictedNames).
  	 */
  	private boolean matches(SafraTreeNode this_node, SafraTreeNode other_node) {
  		assert(this_node != null && other_node != null);
  
  		if (this_node == null || other_node == null) {
  			return false;
  		}
  
  		if (!renameableNames().get(this_node.getID())) {
  			// this is not a new node, so we require a perfect match..
  			if (other_node.getID() != this_node.getID()) {
  				return false;
  			}
  		} else {
  			// we are flexible with the id, as long as the id wasn't removed
  			//  in the tree
  			if (restrictedNames().get(other_node.getID())) {
  				return false;
  			}
  		}
  
  		assert(this_node.getLabeling().equals(other_node.getLabeling()));
  		assert(this_node.hasFinalFlag() == other_node.hasFinalFlag());
  
  		// this node looks good, now the children
  		SafraTreeNode this_child = this_node.getOldestChild();
  		SafraTreeNode other_child = other_node.getOldestChild();
  
  		while (this_child != null && other_child != null) {
  			if (!matches(this_child, other_child)) {
  				return false;
  			}
  
  			this_child = this_child.getYoungerBrother();
  			other_child = other_child.getYoungerBrother();
  		}
  		assert(this_child == null && other_child == null);
  
  		return true;
  	}
  }
  