Is there a scala replacement for Guava MultiSet and Table concepts?

Question

To use guava Table and Multiset in scala? are there already different concenpts in scala instead of importing guava library for this usage?

Answer 1

You could use Map[(R, C), V] instead of Table<R, C, V> and Map[T, Int] instead of Multiset<T>. You could also add helper methods to Map[T, Int] like this:

implicit class Multiset[T](val m: Map[T, Int]) extends AnyVal {
  def setAdd(e: T, i: Int = 1) = {
    val cnt = m.getOrElse(e, 0) + i
    if (cnt <= 0) m - e
    else m.updated(e, cnt)
  }
  def setRemove(e: T, i: Int = 1) = setAdd(e, -i)
  def count(e: T) = m.getOrElse(e, 0)
}

val m = Map('a -> 5)

m setAdd 'a
// Map('a -> 6)

m setAdd 'b
// Map('a -> 5, 'b -> 1)

m setAdd ('b, 10)
// Map('a -> 5, 'b -> 10)

m setRemove 'a
// Map('a -> 4)

m setRemove ('a, 6)
// Map()

m count 'b
// 0

(m setAdd 'a) count 'a
// 6