private ParseTree convertNode(Tree ast) {

		ParseTree parent = new ParseTree();
		parent.value = ast.toString();
		parent.attribute = EsperCompiler.getTokenName(Integer.parseInt(Integer.toString(ast.getType())));
		
		for (int i = 0; i < ast.getChildCount(); i++) {
			parent.children.add(convertNode(ast.getChild(i)));
		}
		
		return parent;
	}