RosettaCodeData/Task/Parametric-polymorphism/Scala/parametric-polymorphism-5.s...

7 lines
324 B
Scala

case class Tree[+A](value: A, left: Option[Tree[A]], right: Option[Tree[A]]) {
def map[B](f: A => B): Tree[B] =
Tree(f(value), left map (_.map(f)), right map (_.map(f)))
def find[B >: A](what: B): Boolean =
(value == what) || left.map(_.find(what)).getOrElse(false) || right.map(_.find(what)).getOrElse(false)
}