提取元组中的元组Haskell

我必须做一个程序，它决定两个圆在haskell中是否重叠。 我定义了以下内容：

-- | A 2D Point.
type Point = (Float,Float)

-- | A Circle is a pair of its center point and its radius.
type Circle = (Point,Float)

我需要做一个距离函数，计算两点之间的距离（因此是两个圆的中心），然后做一个函数，通过检查两个中心之间的距离是否小于半径（或半径）之和来确定它们是否重叠

问题是中心是一个多边形，半径是一个元素 以下是我为距离制作的函数：

-- | Distance between two points.
distance :: Point -> Point -> Float
distance p1 p2 = ((snd p1 - fst p1)^2 + (snd p2 - snd p1)^2)^(1/2)

现在我需要做距离<2*半径，但我不能把它们结合起来，因为距离应该在一个元素上，半径应该在一个元素上

以下是我尝试过的：

-- | 'True' if the given circles overlap, else 'False'.
overlap :: Circle -> Circle -> Bool
overlap c1 c2 = [distance x,y | x<-(x,y):c1, y<-(x1,y1):c2] < [sum z,z1 | z<-(z):c1, z1<-(z1):c2]

---

你实际上已经解决了自己的问题，只是你还不知道而已

通过检查两个中心之间的距离是否小于半径（或半径）之和来确定它们是否重叠的函数

我将把这句话直接翻译成Haskell：

a function which decides if they are overlapping
   |           by checking that the distance
   |               |    between the two centres
   |               |         |           |    is smaller than
   |               |         |           |       |      the sum of
   |               |         |           |       |           |
   |               |         |           |       |     the radiuses
   |               |         |           |       |     |     |    |
   v               v         v           v       v     v     v    v
overlap c1 c2 = distance (centre c1) (centre c2) < radius c1 + radius c2

---

就这么简单

非常感谢您的帮助，这里有一个

sqrt

函数，它可能比

^（1/2）

更具可读性。

a function which decides if they are overlapping
   |           by checking that the distance
   |               |    between the two centres
   |               |         |           |    is smaller than
   |               |         |           |       |      the sum of
   |               |         |           |       |           |
   |               |         |           |       |     the radiuses
   |               |         |           |       |     |     |    |
   v               v         v           v       v     v     v    v
overlap c1 c2 = distance (centre c1) (centre c2) < radius c1 + radius c2

centre c = fst c
radius c = snd c