How get random element from list in one line

Question

I have following code:

val A = List(...)
val items = A.map(..magic#1..).filter(..magic#2..).map(..magic#3..)
val rndItem = items(Random.nextInt(items.size))

But I want this:

val A = List(...)
val rndItem = A.map(..magic#1..).filter(..magic#2..).map(..magic#3..).getRandom()

Can I do this on scala?

I seen question#1 and question#2

I don't think so, unless you will write some helper code (most likely using pimp-my-library pattern), but is this an option for you? — om-nom-nom, Jul 30 '14 at 13:54

score 2 · Accepted Answer · answered Jul 30 '14 at 13:54

Sure - use the pimp my library pattern to "add a method" to List:

// We'll use a value class to avoid allocations (in theory anyway)
implicit class RandomList[A](val self: List[A]) extends AnyVal {
  def getRandom(): A = self(Random.nextInt(self.size))
}

How get random element from list in one line

1 Answers1