- /*
- * Copyright 2002,2004 The Apache Software Foundation.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
- package org.apache.commons.jexl.parser;
-
- import org.apache.commons.jexl.JexlContext;
-
- import java.util.Collection;
- import java.util.Map;
-
- /**
- * function to see if reference doesn't exist in context
- *
- * @author <a href="mailto:geirm@apache.org">Geir Magnusson Jr.</a>
- * @author <a href="mailto:tobrien@apache.org">Tim O'Brien</a>
- * @version $Id: ASTEmptyFunction.java,v 1.6 2004/08/23 13:30:36 dion Exp $
- */
- public class ASTEmptyFunction extends SimpleNode
- {
- public ASTEmptyFunction(int id)
- {
- super(id);
- }
-
- public ASTEmptyFunction(Parser p, int id)
- {
- super(p, id);
- }
-
- /** Accept the visitor. **/
- public Object jjtAccept(ParserVisitor visitor, Object data)
- {
- return visitor.visit(this, data);
- }
-
- public Object value(JexlContext jc)
- throws Exception
- {
- SimpleNode sn = (SimpleNode) jjtGetChild(0);
-
- /*
- * I can't believe this
- */
-
- Object o = sn.value(jc);
-
- if (o == null)
- return Boolean.TRUE;
-
- if (o instanceof String && "".equals((String) o))
- return Boolean.TRUE;
-
- if (o.getClass().isArray() && ((Object[])o).length == 0)
- return Boolean.TRUE;
-
- if (o instanceof Collection && ((Collection)o).isEmpty())
- return Boolean.TRUE;
-
- /*
- * Map isn't a collection
- */
- if (o instanceof Map && ((Map)o).isEmpty())
- return Boolean.TRUE;
-
- return Boolean.FALSE;
- }
- }