interface IPoint

	def sum as int


struct Point implements IPoint

	enum TypeEnum
		Black
		White

	shared
		var _numCreations as int
		get numCreations from var

	var _x as int
	var _y as int
	var _type as TypeEnum

	cue init(x as int, y as int)
		_x = x
		_y = y
		_type = TypeEnum.Black
		_numCreations += 1

	get x from var
	
	get y from var
	
	def sum as int
		return .x + .y

	pro type from var

	pro [i as int] as int
		get
			return i * 2
		set
			pass			


class Test

	def main is shared
		assert Point.numCreations == 0
		p = Point(1, 2)
		assert p.x == 1
		assert p.y == 2
		assert p.sum == 3
		assert p[2] == 4
		p[4] = 10
		assert Point.numCreations == 1