-
Notifications
You must be signed in to change notification settings - Fork 6
Expand file tree
/
Copy pathIxToMultimap.java
More file actions
82 lines (61 loc) · 2.55 KB
/
Copy pathIxToMultimap.java
File metadata and controls
82 lines (61 loc) · 2.55 KB
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
/*
* Copyright 2011-2016 David Karnok
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* 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 CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package ix;
import java.util.*;
final class IxToMultimap<T, K, V> extends IxSource<T, Map<K, Collection<V>>> {
final IxFunction<? super T, ? extends K> keySelector;
final IxFunction<? super T, ? extends V> valueSelector;
IxToMultimap(Iterable<T> source, IxFunction<? super T, ? extends K> keySelector, IxFunction<? super T, ? extends V> valueSelector) {
super(source);
this.keySelector = keySelector;
this.valueSelector = valueSelector;
}
@Override
public Iterator<Map<K, Collection<V>>> iterator() {
return new ToMapIterator<T, K, V>(source.iterator(), keySelector, valueSelector);
}
static final class ToMapIterator<T, K, V> extends IxSourceIterator<T, Map<K, Collection<V>>> {
final IxFunction<? super T, ? extends K> keySelector;
final IxFunction<? super T, ? extends V> valueSelector;
ToMapIterator(Iterator<T> it, IxFunction<? super T, ? extends K> keySelector, IxFunction<? super T, ? extends V> valueSelector) {
super(it);
this.keySelector = keySelector;
this.valueSelector = valueSelector;
}
@Override
protected boolean moveNext() {
Iterator<T> it = this.it;
IxFunction<? super T, ? extends K> keySelector = this.keySelector;
IxFunction<? super T, ? extends V> valueSelector = this.valueSelector;
Map<K, Collection<V>> result = new HashMap<K, Collection<V>>();
while (it.hasNext()) {
T t = it.next();
K k = keySelector.apply(t);
Collection<V> coll = result.get(k);
if (coll == null) {
coll = new ArrayList<V>();
result.put(k, coll);
}
V v = valueSelector.apply(t);
coll.add(v);
}
value = result;
hasValue = true;
done = true;
return true;
}
}
}