Convert List of Ints to a SortedSet in Scala
If I have a List of Ints like:
val myList = List(3,2,1,9)
what is the right/preferred way to create a SortedSet from a List or Seq of Ints, where the items are sorted from least to greatest?
If you held a gun to my head I would have said:
val itsSorted = collection.SortedSet(myList)
but I get an error regarding that there is no implicit ordering defined for List[Int].
Answer
Use:
collection.SortedSet(myList: _*)
The way you used it, the compiler thinks you want to create a SortedSet[List[Int]] not a SortedSet[Int]. That's why it complains about no implicit Ordering for List[Int].
Notice the repeated parameter of type A* in the signature of the method:
def apply [A] (elems: A*)(implicit ord: Ordering[A]): SortedSet[A]
To treat myList as a sequence argument of A use, the _* type annotation.