Conway's game of life

[gedaiu via Digitalmars-d-learn]

Uf...  you are right!

I've fixed it.

Thanks!


On Monday, 2 February 2015 at 11:23:17 UTC, FG wrote:
> 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.