左上から一回転

 let directions = [ (x: -1, y: -1), (x: 0, y: -1), (x: 1, y: -1), (x: 1, y: 0), (x: 1, y: 1), (x: 0, y: 1), (x: -1, y: 0), (x: -1, y: 1), ] ... for direction in directions {