在Scala中优雅地遍历源代码

val list = List(1, 2, 3, 4, 5)
for (element <- list) {
  println(element)
}

val list = List(1, 2, 3, 4, 5)
val squaredList = list.map(x => x * x)
println(squaredList)

sealed trait Node
case class Leaf(value: Int) extends Node
case class Branch(left: Node, right: Node) extends Node

def traverse(node: Node): Unit = node match {
  case Leaf(value) => println(value)
  case Branch(left, right) =>
    traverse(left)
    traverse(right)
}

val tree = Branch(Leaf(1), Branch(Leaf(2), Leaf(3)))
traverse(tree)