Re: [gnugo-devel] trevor_1_20.5

[Gunnar Farneback]

Trevor wrote:
> This upper/lower case convention does seem to be used consistently.
> This case, for example, the letters flip between X & O, depending
> on the attack order.

I guess there's a missing negation in the first sentence. The
convention is that *existing* X stones get upper case letters while O
stones and empty vertices (which are used to place stones of either
color on in the reading constraints) get lower case letters. This is
actually even documented, in doc/patterns.texi:

| Here we have given the label @samp{a} to the empty spot to the right
| of the considered move and the label @samp{B} to the @samp{X} stone
| in the pattern. In addition to these, @samp{*} can also be used as a
| label. A label may be any lowercase or uppercase ascii letter except
| OoXxt. By convention we use uppercase letters for X stones and
| lowercase for O stones and empty intersections. When labeling a
| stone that's part of a larger string in the pattern, all stones of
| the string should be marked with the label. (These conventions are
| not enforced by the pattern compiler, but to make the database
| consistent and easy to read they should be followed.)

/Gunnar