public struct Square: Equatable {

	public struct Position: Equatable {
		public let file: Int8
		public let rank: Int8

		public var index: Int {
			return Int(8*(8-rank)+file-1)
		}

		public static func == (lhs: Position, rhs: Position) -> Bool {
			return lhs.index == rhs.index
		}
	}

	public let position: Position
	public let index: Int
	var piece: Piece? = nil
	public let color: Color

	public static func == (lhs: Square, rhs: Square) -> Bool {
		return lhs.position == rhs.position
	}
}