Question

I have the following function:

type Coordin = (Int,Int)

data Grid = Open
          | Taken Int

myOwn :: Coordin -> Grid -> Bool
myOwn (x,y) grid  
    | ((board)!!(y)!!(x)) == Taken n           = True
    | otherwise                                = False

I would like n to mean any number (as Int is specified as such in Data Grid for that particular type) but the thing just won’t work!! I thought about using a where clause but if there are any other ideas it would be much appreciated. Thanks.

Answer 1

With inspiration form camccann’s solution:

type Board = [[Grid]]

isTaken :: Grid -> Bool
isTaken (Taken _) = True
isTaken Open      = False

myOwn :: Coordin -> Board -> Bool
myOwn (x,y) board = isTaken (board !! y !! x)