1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
|
/*
* esodata - data structures and other things, of varying utility
* Copyright 2022, Ben Culkin
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
package bjc.esodata;
import java.util.*;
import bjc.data.Pair;
/**
* A map that supports multiple values for a given key.
*
* The thing that will tend to vary with the implementation is what they do with
* duplicate values for the same key.
*
* @author bjcul
*
* @param <KeyType> The key type of the map
* @param <ValueType> The value type of the map.
*/
public interface Multimap<KeyType, ValueType> {
/**
* Add a key-value mapping to the map.
*
* @param key The key to store the value under.
*
* @param value The value to store.
*/
void add(KeyType key, ValueType value);
/**
* Delete a particular key-value mapping from the map.
*
* @param key The key of the mapping to remove.
*
* @param value The value of the mapping to remove.
*/
void remove(KeyType key, ValueType value);
/**
* Delete all of the values associated with a particular key.
*
* @param key The key to remove values for.
*/
void remove(KeyType key);
/**
* Get a set containing all of the values that are recorded for that key.
*
* @param key The key to look up values for.
*
* @return A set containing all of the values that have been mapped to that key.
*/
Set<ValueType> get(KeyType key);
/**
* Get the single value in the map, if there is one.
*
* @param key The key to look up
* @return An optional containing the key if it is there once, or empty if it is
* there either no or more than one times
*/
Optional<ValueType> getSingle(KeyType key);
/**
* Check if there is at least one value mapped to the given key.
*
* @param key The key to check for mappings for.
*
* @return Whether or not there is at least one value mapped to the key.
*/
boolean contains(KeyType key);
/**
* Check if there is at least one instance of a particular key-value mapping.
*
* @param key The key to check for mappings for.
*
* @param value The value to check for mappings for.
*
* @return Whether or not there is at least one instance of the given key-value
* mapping.
*/
boolean contains(KeyType key, ValueType value);
/**
* Retrieve an iterator over the values in this map
*
* @return An iterator over the values in this map
*/
Iterator<Pair<KeyType, ValueType>> iterator();
}
|
