code: //==============================================================================
  //	
  //	Copyright (c) 2002-
  //	Authors:
  //	* Dave Parker <david.parker@comlab.ox.ac.uk> (University of Oxford)
  //	* Mark Kattenbelt <mark.kattenbelt@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 parser.ast;
  
  import parser.type.TypeBool;
  import parser.visitor.ASTVisitor;
  import prism.PrismLangException;
  
  public class DeclarationBool extends DeclarationType
  {
  	public DeclarationBool()
  	{
  		// The type stored for a Declaration/DeclarationType object
  		// is static - it is not computed during type checking.
  		// (But we re-use the existing "type" field for this purpose)
  		setType(TypeBool.getInstance());
  	}
  	
  	/**
  	 * Return the default start value for a variable of this type.
  	 */
  	public Expression getDefaultStart()
  	{
  		return Expression.False();
  	}
  	/*TODO
  	public Expression getStart(ModulesFile parent)
  	{
  		if (parent != null && parent.getInitialStates() != null)
  			return null;
  
  		return start != null ? start : Expression.False();
  	}*/
  
  	// Methods required for ASTElement:
  	
  	/**
  	 * Visitor method.
  	 */
  	public Object accept(ASTVisitor v) throws PrismLangException
  	{
  		return v.visit(this);
  	}
  
  	/**
  	 * Convert to string.
  	 */
  	public String toString()
  	{
  		return "bool";
  	}
  
  	/**
  	 * Perform a deep copy.
  	 */
  	public ASTElement deepCopy()
  	{
  		DeclarationBool ret = new DeclarationBool();
  		ret.setPosition(this);
  		return ret;
  	}
  }
  