Slowly relearning Scala syntax

Max.scala

import java.util.NoSuchElementException

import cats._
import cats.implicits._

import scala.annotation.tailrec

object Max extends App {

  def maximum[A : Order](list: List[A]): A = list match {
    case Nil      => throw new NoSuchElementException
    case x :: Nil => x
    case x :: xs  => x max maximum(xs)
  }

  def maximumTr[A : Order](list: List[A]): A = {
    @tailrec
    def go(list: List[A], y: A): A = list match {
      case Nil => y
      case x :: xs  => go(xs, x max y)
    }

    list match {
      case Nil => throw new NoSuchElementException
      case x :: xs => go(xs, x)
    }
  }

  println(maximum(List(1,5,3,6)))
  println(maximumTr(List(1,5,3,6)))

}