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
|
/*
* =========================================================================================
* Copyright © 2013-2015 the kamon project <http://kamon.io/>
*
* 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 kamon.util
object MapMerge {
/**
* Merge two immutable maps with the same key and value types, using the provided valueMerge function.
*/
implicit class Syntax[K, V](val map: Map[K, V]) extends AnyVal {
def merge(that: Map[K, V], valueMerge: (V, V) ⇒ V): Map[K, V] = {
val merged = Map.newBuilder[K, V]
map.foreach {
case (key, value) ⇒
val mergedValue = that.get(key).map(v ⇒ valueMerge(value, v)).getOrElse(value)
merged += key → mergedValue
}
that.foreach {
case kv @ (key, _) if !map.contains(key) ⇒ merged += kv
case other ⇒ // ignore, already included.
}
merged.result();
}
}
}
|
