RE: computer-go: Sharing Go modules

["Mark Boon" <tesuji@xxxxxxxxx>]

> -----Original Message-----
> From: owner-computer-go@xxxxxxxxxxxxxxxxx
> [mailto:owner-computer-go@xxxxxxxxxxxxxxxxx]On Behalf Of Magnus Persson
> Sent: Wednesday, May 16, 2001 7:22 PM
> To: computer-go@xxxxxxxxxxxxxxxxx
> Subject: Re: computer-go: Sharing Go modules
>
>
> I use the same way of accessing an one-dimensional array except that
> I have two layers of border data, because I once thought that i would
> need to access a points two spaces away from a given point without
> having to check any boundaries.
>
> In practice I almost never do that (I only look at points one space
> away) so every array I use in my program spends a lot of memory (and
> since all my array big enough to hold 21x21 boards they are rather
> large).
>

In the early days I started out with a 21x21 array too, until I realized it
was a mistake. You get a two-point border at the sides, but only a one-point
border at the top and bottom.

> The only drawback I have experienced is in patternmatching - because
> the way I do it is necessary to work with x,y coordinates, and check
> for boundaries.
>

Yes, pattern-matching is one of those cases where using x,y coordinates is
often  more convenient.

>
> --------
> var
>   p: boardoffset;
> begin
>   for u := 0 to 3 do
>   begin
>     Inc(p, URDL[u]); // UpRightDownLeft
>     DoSomething(p);
>   end;
> end;

I'm sure there are a dozen similar implementations in other Go programs.