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/*
* =========================================================================================
* 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();
}
}
}
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