fileprivate func getDirectionalMoves(from pos: Square.Position, with dir: [(Int8, Int8)]) -> [Square.Position] {
    var squares = [Square.Position]()
    for i: (Int8, Int8) in dir {
        var currentSquare = pos + i
        while currentSquare.index != nil {
            squares.append(currentSquare)
            currentSquare += i 
        }
    }
    return squares
}
protocol DiagonalMoves {
    func getDiagonalMoves(from pos: Square.Position) -> [Square.Position]
}

extension DiagonalMoves {
    func getDiagonalMoves(from pos: Square.Position) -> [Square.Position] {
        getDirectionalMoves(from: pos, with: [(1, -1), (1, 1), (-1, 1), (-1, -1)])
    }
}

protocol LinearMoves {
    func getLinearMoves(from pos: Square.Position) -> [Square.Position]
}

extension LinearMoves {
    func getLinearMoves(from pos: Square.Position) -> [Square.Position] {
        getDirectionalMoves(from: pos, with: [(1, 0), (0, 1), (-1, 0), (0, -1)])
    }
}