Re: [gnugo-devel] Pattern for seki (bug 175)

[Gunnar Farnebäck]

Joseph Piche wrote:
> I created a regression test for bug 175 (the patch is in trac). Then I
> started looking at the pattern code after reading the documentation. It
> was difficult for me to try and understand how to generate a pattern,

The pattern code is rather complex due to various speed optimizations
and some semantical subtleties, not to speak of the terribly hairy
mkpat.c file. Constructing patterns is supposed to be easier.

> so I wanted to have someone else look at this and see if I got
> everything right.

It looks fine.

> I was also wondering where the code for defending against a seki
> would go; right after it in S16?

Yes, just like S12 is followed by S13.

> One more thing is that after re-compiling with this new pattern,
> gnugo passes after white responds (typically C2 or C1); is there
> something else I need to do to let gnugo know how to finish the
> invasion?

Once there is a stone in place the responsibility falls to the semeai
analysis code in semeai.c and owl.c. Unfortunately that has been known
to make mistakes now and then. Occasionally it's necessary to help it
with explicit patterns like S10b and similar but if possible we prefer
to avoid that.

/Gunnar