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      1 /*
      2  * Licensed to the Apache Software Foundation (ASF) under one
      3  * or more contributor license agreements. See the NOTICE file
      4  * distributed with this work for additional information
      5  * regarding copyright ownership. The ASF licenses this file
      6  * to you under the Apache License, Version 2.0 (the  "License");
      7  * you may not use this file except in compliance with the License.
      8  * You may obtain a copy of the License at
      9  *
     10  *     http://www.apache.org/licenses/LICENSE-2.0
     11  *
     12  * Unless required by applicable law or agreed to in writing, software
     13  * distributed under the License is distributed on an "AS IS" BASIS,
     14  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     15  * See the License for the specific language governing permissions and
     16  * limitations under the License.
     17  */
     18 /*
     19  * $Id: Minus.java 468655 2006-10-28 07:12:06Z minchau $
     20  */
     21 package org.apache.xpath.operations;
     22 
     23 import org.apache.xpath.XPathContext;
     24 import org.apache.xpath.objects.XNumber;
     25 import org.apache.xpath.objects.XObject;
     26 
     27 /**
     28  * The binary '-' operation expression executer.
     29  */
     30 public class Minus extends Operation
     31 {
     32     static final long serialVersionUID = -5297672838170871043L;
     33 
     34   /**
     35    * Apply the operation to two operands, and return the result.
     36    *
     37    *
     38    * @param left non-null reference to the evaluated left operand.
     39    * @param right non-null reference to the evaluated right operand.
     40    *
     41    * @return non-null reference to the XObject that represents the
     42    *         result of the operation.
     43    *
     44    * @throws javax.xml.transform.TransformerException
     45    */
     46   public XObject operate(XObject left, XObject right)
     47           throws javax.xml.transform.TransformerException
     48   {
     49     return new XNumber(left.num() - right.num());
     50   }
     51 
     52   /**
     53    * Evaluate this operation directly to a double.
     54    *
     55    * @param xctxt The runtime execution context.
     56    *
     57    * @return The result of the operation as a double.
     58    *
     59    * @throws javax.xml.transform.TransformerException
     60    */
     61   public double num(XPathContext xctxt)
     62           throws javax.xml.transform.TransformerException
     63   {
     64 
     65     return (m_left.num(xctxt) - m_right.num(xctxt));
     66   }
     67 
     68 }
     69