Re: [gnugo-devel] trevor_1_23.4.tar.gz

[Gunnar Farneback]

Trevor wrote:
> http://www.public32.com/games/go/trevor_1_23.4.tar.gz

What is this part of the patch about?

> @@ -874,7 +878,8 @@
>   * This is the case if
>   * 1. There is no neighboring empty intersection.
>   * 2. There is no neighboring opponent string with exactly one liberty.
> - * 3. There is no neighboring friendly string with more than one liberty.
> + * 3. Thers is a neighboring friendly string with more than one liberty.
> + *
>   */
>  int 
>  is_suicide(int pos, int color)

The full context is this documentation comment:

/*
 * is_suicide(pos, color) determines whether the move (color) at
 * (pos) would be a suicide.
 *
 * This is the case if
 * 1. There is no neighboring empty intersection.
 * 2. There is no neighboring opponent string with exactly one liberty.
 * 3. There is no neighboring friendly string with more than one liberty.
 */

I'm quite certain that this formulation is correct without the patch.

> +static void
> +set_goal_worm(int str, int value, char goal[BOARDMAX]) {
> +  int k;
> +  int color = board[str];
> +  if (goal[str]) { return; }
> +  goal[str] = value;
> +  for (k=0;k<4;k++) {
> +    int pos = str+delta[k];
> +    if (board[pos] == color) {
> +      set_goal_worm(pos, value, goal);
> +    }
> +  }
> +}

This function should be possible to replace with mark_string() from
board.c. Although they do differ subtly, I think
set_larger_goal_worm() can use mark_string() after minor
modifications.

> Pattern RA007
> 
> X*   snapback
> X.
> 
> :-,A,value(75)

The symmetry is wrong.

> 
> aA   snapback
> ab
> 
> ; rgoal[a] == 1 
> ; && NORTH(A) != color
> ; && SOUTH(A) != color
> ; && EAST(A) != color
> ; && WEST(A) != color
> ; && olib(A) == 1 && xlib(b)==1

Why this complex constraint? Wouldn't it be more straightforward and
efficient to modify the pattern to the one below?

?x?
X*x
X.?

/Gunnar