1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.el;
18
19 import javax.servlet.jsp.el.ELException;
20
21 /**
22 *
23 * <p>This is the superclass for all binary operators
24 *
25 * @author Nathan Abramson - Art Technology Group
26 * @version $Change: 181177 $$DateTime: 2001/06/26 08:45:09 $$Author: bayard $
27 **/
28
29 public abstract class BinaryOperator
30 {
31 //-------------------------------------
32 /**
33 *
34 * Constructor
35 **/
36 public BinaryOperator ()
37 {
38 }
39
40 //-------------------------------------
41 // Expression methods
42 //-------------------------------------
43 /**
44 *
45 * Returns the symbol representing the operator
46 **/
47 public abstract String getOperatorSymbol ();
48
49 //-------------------------------------
50 /**
51 *
52 * Applies the operator to the given pair of values
53 **/
54 public abstract Object apply (Object pLeft,
55 Object pRight)
56 throws ELException;
57
58 //-------------------------------------
59 /**
60 *
61 * Returns true if evaluation is necessary given the specified Left
62 * value. The And/OrOperators make use of this
63 **/
64 public boolean shouldEvaluate (Object pLeft)
65 {
66 return true;
67 }
68
69 //-------------------------------------
70 /**
71 *
72 * Returns true if the operator expects its arguments to be coerced
73 * to Booleans. The And/Or operators set this to true.
74 **/
75 public boolean shouldCoerceToBoolean ()
76 {
77 return false;
78 }
79
80 //-------------------------------------
81 }