Bloody Thunderbird has sent a reply to the OP and not to the NG.
On 2015-02-02 at 11:45, gedaiu wrote:
I don't think that the line of code is wrong. If use && the function will check
for neighbours only on diagonals. Having || allows the search on the vertical and
horizontal axis and diagonals.
In short: Yes, && alone would check only diagonals, but I forgot to tell you to
also change the ==.
(diff1 == 1 || diff2 == 1) -- bad, accepts whole neighbouring rows and columns
(diff1 == 1 && diff2 == 1) -- bad, accepts only neighbouring diagonals
(diff1 <= 1 && diff2 <= 1) -- correct, I think :)
This unittest should show the difference:
unittest {
CellList world = [ Cell(0,0), Cell(0,1), Cell(0,2), Cell(0,3) ];
assertEqual(Cell(1,1).neighbours(world), 3);
}
Cell(0,3) is not a neighbour bit fits the (diff1 == 1 || diff2 == 1) criterion.
