class X

	def main is shared
		X().run
		
	def run
		# trying not to use features not tested at this point in the test suite:
		# list = [2, 1, 3]
		list = .makeList
		
		list.sort(ref .compare)
		assert list == [1, 2, 3]

		list.sort(ref .reverseCompare)
		assert list == [3, 2, 1]

		# in the future, inline delegate expressions and type inference:
		# list.sort(def(x as int, y as int) = y.compareTo(x))
		# list.sort(def(x, y) = y.compareTo(x))

	def compare(x as int, y as int) as int is shared
		return x.compareTo(y)

	def reverseCompare(x as int, y as int) as int is shared
		return y.compareTo(x)

	def makeList as List<of int>
		t = List<of int>()
		t.add(2)
		t.add(1)
		t.add(3)
		return t