Re: [gnugo-devel] ALL_MOVE considered superfluous

[Arend Bayer]

Inge wrote:

> > This is not a complete answer but to avoid confusion I want to point
> > out that there never has been an ATTACK_BOTH_MOVE. What we have had is
> > DEFEND_BOTH_MOVE, a converse to ATTACK_EITHER_MOVE.
>
> Right!  My wrong.  But the question still remains.

As far as I remember you introduced the name ALL_MOVE and had some
further plans with it. Personally I've nothing against renaming it back
to DEFEND_BOTH_MOVE...
Instead of continueing the renaming game, one could try to make the
meaning of DEFEND_BOTH_MOVE more clear, and try to improve its
valuation.
DEFEND_BOTH_MOVE is _not_ the same as two defend move reasons. A
DEFEND_BOTH_MOVE concerns two stable worms, i.e. if opponent attacks any
single of the two, he cannot capture it. But if he attacks both of them
at once, we cannot defend both at a time. A DEFEND_BOTH_MOVE prevents
this.
This nowhere explicitly documented so. And IIRC some code in
value_moves.c/move_reasons.c isn't exactly sure about this meaning.

Arend