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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.functor.core.composite;
18  
19  import org.apache.commons.functor.Predicate;
20  
21  /**
22   * {@link #test Tests} <code>true</code> iff
23   * at least one of its children test <code>true</code>.
24   * Note that by this definition, the "or" of
25   * an empty collection of predicates tests <code>false</code>.
26   * <p>
27   * Note that although this class implements
28   * {@link java.io.Serializable Serializable}, a given instance will
29   * only be truly <code>Serializable</code> if all the
30   * underlying functors are.  Attempts to serialize
31   * an instance whose delegates are not all
32   * <code>Serializable</code> will result in an exception.
33   * </p>
34   * @version $Revision: 1156320 $ $Date: 2011-08-10 21:14:50 +0200 (Wed, 10 Aug 2011) $
35   * @author Rodney Waldhoff
36   */
37  public final class Or extends BasePredicateList {
38  
39      /**
40       * serialVersionUID declaration.
41       */
42      private static final long serialVersionUID = -1636233158061690073L;
43  
44      // constructor
45      // ------------------------------------------------------------------------
46      /**
47       * Create a new Or.
48       */
49      public Or() {
50          super();
51      }
52  
53      /**
54       * Create a new Or instance.
55       *
56       * @param predicates
57       */
58      public Or(Iterable<Predicate> predicates) {
59          super(predicates);
60      }
61  
62      /**
63       * Create a new Or instance.
64       *
65       * @param predicates
66       */
67      public Or(Predicate... predicates) {
68          super(predicates);
69      }
70  
71      /**
72       * Fluently add a Predicate.
73       * @param p Predicate to add
74       * @return this
75       */
76      public Or or(Predicate p) {
77          super.addPredicate(p);
78          return this;
79      }
80  
81      // predicate interface
82      // ------------------------------------------------------------------------
83      /**
84       * {@inheritDoc}
85       */
86      public boolean test() {
87          for (Predicate p : getPredicateList()) {
88              if (p.test()) {
89                  return true;
90              }
91          }
92          return false;
93      }
94  
95      /**
96       * {@inheritDoc}
97       */
98      public boolean equals(Object that) {
99          return that == this || (that instanceof Or && equals((Or) that));
100     }
101 
102     /**
103      * Learn whether another Or is equal to this.
104      * @param that Or to test
105      * @return boolean
106      */
107     public boolean equals(Or that) {
108         return getPredicateListEquals(that);
109     }
110 
111     /**
112      * {@inheritDoc}
113      */
114     public int hashCode() {
115         return "Or".hashCode() ^ getPredicateListHashCode();
116     }
117 
118     /**
119      * {@inheritDoc}
120      */
121     public String toString() {
122         return "Or<" + getPredicateListToString() + ">";
123     }
124 
125 }