Scala example source code file (OrderingTest.scala)

This example Scala source code file (OrderingTest.scala) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Scala tags/keywords

app, array, list, list, ordering, ordering, some, t, t, test, the, the

The Scala OrderingTest.scala source code

object Test extends App {
  def test[T](t1 : T, t2 : T)(implicit ord : Ordering[T]) = {
    val cmp = ord.compare(t1, t2);
    val cmp2 = ord.compare(t2, t1);

    assert((cmp == 0) == (cmp2 == 0))
    assert((cmp > 0) == (cmp2 < 0))
    assert((cmp < 0) == (cmp2 > 0))
  } 

  def testAll[T](t1 : T, t2 : T)(implicit ord : Ordering[T]) = {
    assert(ord.compare(t1, t2) < 0)
    test(t1, t2);
    test(t1, t1);
    test(t2, t2);
  }

  assert(Ordering[String].compare("australopithecus", "brontausaurus") < 0)
  // assert(Ordering[Unit].compare((), ()) == 0) 
 
  testAll("bar", "foo");
  testAll[Byte](0, 1);
  testAll(false, true)
  testAll(1, 2);
  testAll(1.0, 2.0);
  testAll(None, Some(1));
  testAll[Iterable[Int]](List(1), List(1, 2));
  testAll[Iterable[Int]](List(1, 2), List(2));
  testAll((1, "bar"), (1, "foo"))
  testAll((1, "foo"), (2, "bar"))
  
  // sortBy
  val words = "The quick brown fox jumped over the lazy dog".split(' ')
  val result = words.sortBy(x => (x.length, x.head))
  assert(result sameElements Array[String]("The", "dog", "fox", "the", "lazy", "over", "brown", "quick", "jumped"))
}