1 /*
2  *  Make.org Core API
3  *  Copyright (C) 2018 Make.org
4  *
5  * This program is free software: you can redistribute it and/or modify
6  *  it under the terms of the GNU Affero General Public License as
7  *  published by the Free Software Foundation, either version 3 of the
8  *  License, or (at your option) any later version.
9  *
10  *  This program is distributed in the hope that it will be useful,
11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  *  GNU Affero General Public License for more details.
14  *
15  *  You should have received a copy of the GNU Affero General Public License
16  *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
17  *
18  */
19 
20 package org.make.core.technical
21 
22 import scala.collection.mutable.{HashMap => MMap}
23 
24 object CollectionUtils {
25 
26   implicit class ImprovedSeq[A](seq: Seq[A]) {
27 
28     @SuppressWarnings(Array("org.wartremover.warts.MutableDataStructures"))
29     def countOccurencesBy[B](fn: A => B): MMap[B, Int] = {
30       val mMap = MMap[B, Int]()
31       seq.foreach(item => {
32         val key = fn(item)
33         mMap.update(key, mMap.getOrElse(key, 0) + 1)
34       })
35       mMap
36     }
37   }
38 }