[gnugo-devel] GTP version 2

[Gunnar Farneback]

As people who read the GTP list already has seen, I have put up an
updated GTP version 2 specification draft at
http://www.lysator.liu.se/~gunnar/gtp
This is not quite final but is complete enough to start using.

I have also put up a GTP patch for GNU Go at
http://www.lysator.liu.se/~gunnar/gnugo/patches/gunnar_3_10.5
Supposedly this should make GNU Go consistent with the specification.

- new global variable gtp_version
- new option --gtp_version
- new function simple_showboard() in showbord.c
- new function get_last_player() in board.c
- gtp code revised for GTP version 2 and uses this by default

The main differences compared to GTP version 1 is that the "black" and
"white" commands have been replaced by a single "play" command.
Similarly "genmove_black" and "genmove_white" have been replaced by
just "genmove". For regression purposes there is a function
"reg_genmove", which primarily is more reasonably named than
"gg_genmove" but which also does away with the optional random seed.

Another change is that there is a "clear_board" command. Previously
board clearing was done as a side effect of the "boardsize" command,
but in GTP version 2 there is no guarantee that this clears the board
at all.

Obsolete commands (e.g. "black" and "white") remain as private
extensions, so old code will probably continue to work. After this
patch the "protocol_version" command returns "2". There is a new
option --gtp-version which can be used to force GTP version. With
"--gtp-version 1", the "protocol_version" command returns "1" and some
behavior is changed to be more traditional.

Things which need doing include:
* Update the various twogtp programs to be GTP version 2 compliant.
* Make the time_settings and time_left commands actually do anything.
* Migrate regression suites from gg_genmove to reg_genmove. I'm not
  sure how best to go about this.

/Gunnar