A comparision of Ordered.

OrderedCompareTest.scala

package net.wrap_trap.scala.examples

import java.util.Comparator

object OrderedCompareTest {
    def main(args : Array[String]) : Unit = {

        System.out.println("called main")
        System.out.println(
            compareAB(new OrderedClass(2), new OrderedClass(1)))
    }
    
    class OrderedClass(val n: Int) extends Ordered[OrderedClass] {
        System.out.println("called new OrderedClass")
        def compare(that: OrderedClass) =  this.n - that.n
    } 

    // View Bound from scala.math.LowPriorityOrderingImplicits 
    implicit def ordered[T <% Comparable[T]]: Ordering[T] = new Ordering[T] {
    /* = implicit def ordered[T](implicit f: T => Comparable[T]): Ordering[T] = new Ordering[T] { */
        System.out.println("called ordered. f: " + implicitly)
        def compare(x: T, y: T): Int = {
            x.compareTo(y) 
        }
    }
    
    // Context Bound
    def compareAB[K:Ordering](a: K, b: K): Int = {
    /* = def compareAB[K](a: K, b: K)(implicit comp: Ordering[K]): Int = { */
        val comp = implicitly
        System.out.println("called compareAB comp:" + comp)
        comp.compare(a, b);
    }
}