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1   /*
2    * *************************************************************************************************************************************************************
3    *
4    * TheseFoolishThings: Miscellaneous utilities
5    * http://tidalwave.it/projects/thesefoolishthings
6    *
7    * Copyright (C) 2009 - 2024 by Tidalwave s.a.s. (http://tidalwave.it)
8    *
9    * *************************************************************************************************************************************************************
10   *
11   * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License.
12   * You may obtain a copy of the License at
13   *
14   *     http://www.apache.org/licenses/LICENSE-2.0
15   *
16   * 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
17   * CONDITIONS OF ANY KIND, either express or implied.  See the License for the specific language governing permissions and limitations under the License.
18   *
19   * *************************************************************************************************************************************************************
20   *
21   * git clone https://bitbucket.org/tidalwave/thesefoolishthings-src
22   * git clone https://github.com/tidalwave-it/thesefoolishthings-src
23   *
24   * *************************************************************************************************************************************************************
25   */
26  package it.tidalwave.role;
27  
28  import javax.annotation.Nonnull;
29  import java.util.Collections;
30  import java.util.Map;
31  import java.util.Optional;
32  import java.util.Set;
33  import it.tidalwave.role.impl.MapAggregate;
34  
35  /***************************************************************************************************************************************************************
36   *
37   * The role of an aggregate object, that is an object which contains other named objects.
38   *
39   * @stereotype Role
40   *
41   * @author  Fabrizio Giudici
42   *
43   **************************************************************************************************************************************************************/
44  @FunctionalInterface
45  public interface Aggregate<T>
46    {
47      public static final Class<Aggregate> _Aggregate_ = Aggregate.class;
48  
49      /***********************************************************************************************************************************************************
50       * Returns an object given its name.
51       *
52       * @param   name      the name
53       * @return  the object
54       **********************************************************************************************************************************************************/
55      @Nonnull
56      public Optional<T> getByName (@Nonnull String name);
57  
58      /***********************************************************************************************************************************************************
59       * Returns the names of contained objects.
60       *
61       * @return  the names of the objects
62       * @since   3.1-ALPHA-8
63       **********************************************************************************************************************************************************/
64      @Nonnull
65      public default Set<String> getNames()
66        {
67          return Collections.emptySet();
68        }
69  
70      /***********************************************************************************************************************************************************
71       * Returns a new instance with the specified (name, value) pairs.
72       *
73       * @param   <T>         the static type of the value
74       * @param   mapByName   the map containing the pairs
75       * @return              the new instance
76       * @since               3.2-ALPHA-1
77       **********************************************************************************************************************************************************/
78      @Nonnull
79      public static <T> Aggregate<T> of (@Nonnull final Map<String, T> mapByName)
80        {
81          return new MapAggregate<>(mapByName);
82        }
83  
84      /***********************************************************************************************************************************************************
85       * Returns a new empty instance that will be populated by means of {@link #with(String, Object)}.
86       *
87       * @param   <T>         the static type of the aggregate
88       * @return              the new instance
89       * @since               3.2-ALPHA-2
90       **********************************************************************************************************************************************************/
91      @Nonnull
92      public static <T> Aggregate<T> newInstance()
93        {
94          return new MapAggregate<>();
95        }
96  
97      /***********************************************************************************************************************************************************
98       * Returns a new instance with the specified (name, value) pair.
99       *
100      * @param   <T>         the static type of the aggregate
101      * @param   name        the name in the pair
102      * @param   value       the value in the pair
103      * @return              the new instance
104      * @since               3.2-ALPHA-1
105      **********************************************************************************************************************************************************/
106     @Nonnull
107     public static <T> Aggregate<T> of (@Nonnull final String name, @Nonnull final T value)
108       {
109         return new MapAggregate<T>().with(name, value);
110       }
111 
112     /***********************************************************************************************************************************************************
113      * Returns a new instance with the specified (name, value) pair.
114      *
115      * @param   name        the name in the pair
116      * @param   value       the value in the pair
117      * @return              the new instance
118      * @since               3.2-ALPHA-1
119      **********************************************************************************************************************************************************/
120     @Nonnull
121     public default Aggregate<T> with (@Nonnull final String name, @Nonnull final T value)
122       {
123         return new MapAggregate<T>().with(name, value);
124       }
125   }