/* 
 *  Copyright (C) 2000 - 2010 TagServlet Ltd
 *
 *  This file is part of Open BlueDragon (OpenBD) CFML Server Engine.
 *  
 *  OpenBD is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  Free Software Foundation,version 3.
 *  
 *  OpenBD 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 OpenBD.  If not, see http://www.gnu.org/licenses/
 *  
 *  Additional permission under GNU GPL version 3 section 7
 *  
 *  If you modify this Program, or any covered work, by linking or combining 
 *  it with any of the JARS listed in the README.txt (or a modified version of 
 *  (that library), containing parts covered by the terms of that JAR, the 
 *  licensors of this Program grant you additional permission to convey the 
 *  resulting work. 
 *  README.txt @ http://www.openbluedragon.org/license/README.txt
 *  
 *  http://www.openbluedragon.org/
 */

/*
   A stack of CFScope's is used to maintain local scopes, comprising the
   local vars and params, and nesting with object, as well as the global scope,
   comprising special global scope's (e.g. document/window in browsers), and
   the true global scope.
 */

package com.naryx.tagfusion.cfm.parser;

import java.util.ArrayList;

import com.naryx.tagfusion.cfm.engine.cfData;
import com.naryx.tagfusion.cfm.engine.cfmRunTimeException;

public class CFScopeStack extends ArrayList<CFScope> {

	private static final long serialVersionUID = 1L;
	
	public void push( CFScope scope ) {
		super.add( scope );
	}

	public void pop() {
		super.remove( size() - 1 );
	}

	public CFScope peek() {
		return super.get( size() - 1 );
	}

	public CFScope peekFirst() {
		return super.get( 0 );
	}

	// returns null if not found
	public cfData get( String name, CFContext context )
	    throws cfmRunTimeException {
		for ( int i = size() - 1; i >= 0; i-- ) {
			CFScope scope = super.get( i );

			if ( scope.containsVar( name ) ) {
				cfData val = scope.get( name, context );
				return val;
			}
		}
		return null;
	}

}