using System; | |
/** | |
* | |
* Licensed to the Apache Software Foundation (ASF) under one or more | |
* contributor license agreements. See the NOTICE file distributed with | |
* this work for additional information regarding copyright ownership. | |
* The ASF licenses this file to You 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. | |
*/ | |
namespace Apache.NMS.Selector | |
{ | |
/// <summary> | |
/// An expression which negates a boolean expression value. | |
/// </summary> | |
public class NOTExpression : BooleanUnaryExpression | |
{ | |
protected override string ExpressionSymbol | |
{ | |
get { return "NOT"; } | |
} | |
public NOTExpression(IExpression left) | |
: base(left) | |
{ | |
} | |
public override object Evaluate(MessageEvaluationContext message) | |
{ | |
object rvalue = Right.Evaluate(message); | |
if(rvalue == null ) return null; | |
if(rvalue is bool ) return !(bool)rvalue; | |
return null; | |
} | |
} | |
} |