[Swift][일일 코드 #1]이동하는 방향 확인하기

typealias Direction = (CGFloat -> Bool)

func direct(initializedOffset: CGFloat) -> (CGFloat -> Bool) {
	var lastOffset = initializedOffset	// 초기 위치를 저장하여 캡쳐링 됩니다.
	func isDirection(offSet: CGFloat) -> Bool {
		let result = lastOffset > offSet ? false : true	// 현재 위치가 마지막 위치보다 크면 true, 작거나 같으면 false를 반환합니다.
		lastOffset = offSet 	// 마지막 위치를 갱신합니다.
		return result;
	}
	return isDirection
}

let checkUpDown: Direction = direct(5)
checkUpDown(10)		// true
checkUpDown(-20)	// false
checkUpDown(30)		// true
checkUpDown(-40)	// false

let checkLeftRight: Direction = direct(3.0)
checkLeftRight(10)	// true
checkLeftRight(-20)	// false
checkLeftRight(30)	// true
checkLeftRight(-40)	// false

func printDirection(isUpDown: Bool, isLeftRight: Bool) {
    switch (isUpDown, isLeftRight) {
    case (true, true):
        println("Direction is Up and Right")
    case (true, false):
        println("Direction is Up and Left")
    case (false, true):
        println("Direction is Down and Right")
    case (false, true):
        println("Direction is Down and Right")
    case (true, _):
        println("Direction is Up")
    case (false, _):
        println("Direction is Down")
    case (_, true):
        println("Direction is Right")
    case (_, false):
        println("Direction is Left")
    default:
        println("It is impossible")
    }
}

printDirection(checkUpDown(-20), checkLeftRight(-30))