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PrimitiveRefs xref
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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
7    * "License"); you may not use this file except in compliance
8    * with the License.  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  package org.apache.giraph.function.primitive;
19  
20  /**
21   * Convenience classes holding primitive values - a reference
22   * to a mutable value.
23   * For use when lambdas need to mutate capturing primitive local variable.
24   * (since lambdas cannot capture and modify local variables)
25   */
26  public interface PrimitiveRefs {
27  
28    // Have public field for convenience, since classes have no logic inside
29    // CHECKSTYLE: stop VisibilityModifierCheck
30  
31    /**
32     * Convenience class holding int value,
33     * for use when lambdas need to mutate capturing int local variable.
34     */
35    public class IntRef {
36      /** value */
37      public int value;
38  
39      /**
40       * Constructor
41       * @param value initial value
42       */
43      public IntRef(int value) {
44        this.value = value;
45      }
46    }
47  
48    /**
49     * Convenience class holding long value,
50     * for use when lambdas need to mutate capturing long local variable.
51     */
52    public class LongRef {
53      /** value */
54      public long value;
55  
56      /**
57       * Constructor
58       * @param value initial value
59       */
60      public LongRef(long value) {
61        this.value = value;
62      }
63    }
64  
65    /**
66     * Convenience class holding int value,
67     * for use when lambdas need to mutate capturing int local variable.
68     */
69    public class ShortRef {
70      /** value */
71      public short value;
72  
73      /**
74       * Constructor
75       * @param value initial value
76       */
77      public ShortRef(short value) {
78        this.value = value;
79      }
80    }
81  
82  
83    /**
84     * Convenience class holding float value,
85     * for use when lambdas need to mutate capturing float local variable.
86     */
87    public class FloatRef {
88      /** value */
89      public float value;
90  
91      /**
92       * Constructor
93       * @param value initial value
94       */
95      public FloatRef(float value) {
96        this.value = value;
97      }
98    }
99  
100   /**
101    * Convenience class holding double value,
102    * for use when lambdas need to mutate capturing double local variable.
103    */
104   public class DoubleRef {
105     /** value */
106     public double value;
107 
108     /**
109      * Constructor
110      * @param value initial value
111      */
112     public DoubleRef(double value) {
113       this.value = value;
114     }
115   }
116 
117   /**
118    * Convenience class holding object values,
119    * for use when lambdas need to mutate capturing object local variable.
120    */
121   public class ObjRef<O> {
122     /** value */
123     public O value;
124 
125     /**
126      * Constructor
127      * @param value initial value
128      */
129     public ObjRef(O value) {
130       this.value = value;
131     }
132   }
133 
134   // CHECKSTYLE: resume VisibilityModifierCheck
135 }