[gnugo-devel] fast liberties & patterns anchored in goal

[Trevor Morris]

http://www.public32.com/games/go/trevor_1_25.1
 - new function fastlib() helper for approxlib family.
 - a pattern can now force the anchor point.
 - matchpat can be run forcing anchor to be in the goal.

The pattern matching changes are in preparation for another revision
to the EXPERIMENTAL_READING (pattern-based tactical reading) code.

The speed improvement by forcing the anchor to be in the goal are
really big, and it might be worth considering doing the same with
the owl patterns.

The main pattern diagram now accepts two new characters: P & Y
(P follows O, Y follows X).  P is the same as O, but that this
point must be the anchor.  Likewise, for Y & X.

Here's sample from my local read_attack.db:

Pattern RA200

XYO
.O*

:8,A,value(14)

XXO
aO*

;olib(a) == 1


Pattern RA201

YO    backfill
O*

:8,A,value(13)

XO
A*

;lib(A) == 2 && olib(*) >= 2