Re: [gnugo-devel] pattern-based reading spinoffs (27.7)

[Arend Bayer]

> Third it would be nice if it could stop triple ko repetitions (all
> legal with respect to the basic ko rule). This is out of scope for the
> existing komaster schemes (except Trevor's new experiment) since they
> only kick in when illegal ko captures are tried. Notice that this
> isn't just a question of bad move ordering, there are valid positions
> where repeating a triple ko is the only useful move, if allowed. I
> think I know a good solution to this by extending the existing
> komaster schemes but I have to implement and test it to know for sure.

I don't know what solution you are thinking of, but an alternative might
be to use the existing caching. If an open read result is found by
a (minimally revised) get_read_result, we know that a superko violation has
occurred. Then we could effectively disallow the move that lead to this
situation by returning a WIN for the opponent.

This could take care of all superko violations. We would have to enforce
use of caching for all recursive functions, and add a "dummy" open read
results for all caching function at all previous game position. This
would take away only a small part of the memory usage of the hash table.

Arend