public struct Square: Equatable {

	public struct Position: Equatable {
		public let file: UInt8
		public let rank: UInt8

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

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

	public let position: Position
	public let index: UInt8
	public var piece: Piece? = nil
	public let color: Color

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