可以使用scala库，可以从字面上看出是在调用 递归函数：

code

import scala.util.control.TailCalls._  val arrayDonuts: Array[String] = Array("Vanilla Donut", "Strawberry Donut", "Plain Donut", "Glazed Donut")  println("\nStep : How to define a tail recursive function using scala.util.control.TailCalls._")  def tailSearch(donutName: String, donuts: Array[String], index: Int): TailRec[Option[Boolean]] = {    if(donuts.length == index) {      done(None) // NOTE: done is imported from scala.util.control.TailCalls._    } else if(donuts(index) == donutName) {      done(Some(true))    } else {      val nextIndex = index + 1      tailcall(tailSearch(donutName, donuts, nextIndex)) // NOTE: tailcall is imported from scala.util.control.TailCalls._    }  }  println("\nStep : How to call tail recursive function using scala.util.control.TailCalls._")  val tailFound = tailcall(tailSearch("Glazed Donut", arrayDonuts, 0))  println(s"Find Glazed Donut using TailCall = ${tailFound.result}") // NOTE: our returned value is wrapped so we need to get it by calling result  val tailNotFound = tailcall(tailSearch("Chocolate Donut", arrayDonuts, 0))  println(s"Find Chocolate Donut using TailCall = ${tailNotFound.result}")

resule:

Step : How to define a tail recursive function using scala.util.control.TailCalls._Step : How to call tail recursive function using scala.util.control.TailCalls._Find Glazed Donut using TailCall = Some(true)Find Chocolate Donut using TailCall = None