Found the problem: I had a bug in my implementation (see Marcus' comment).
The solution provided by Dan (using a 2d array) seems better, but right now
I'm just focussing on making it work ;)
On Thu, Apr 10, 2014 at 9:48 AM, Stijn Muylle
All,
I ran into a small problem using guards, and I don't really understand what I'm doing wrong.
I have this code:
---------------------------------- import Data.List.Split type Cell = Bool data Board = Board [[Cell]] deriving Show
trueList = True : trueList
createBoard :: Int -> Int -> Board createBoard x y = Board (chunksOf x (take (x * y) trueList))
getCellAt :: Int -> Int -> Board -> Cell getCellAt x y (Board b) | x >= (length b) = False | y >= (length (b !! 0)) = False | otherwise = (b !! x) !! y
-----------------------------------
When I try to execute this:
getCellAt (-1) 0 $ createBoard 3 3
I get a negative index exception. However, as -1 is smaller than 3 (length of the board), I would expect False to be returned.
Am I overlooking something?
Thanks! Stijn