Re: computer-go: Go Text Protocol (GTP)

[Don Dailey <drd@xxxxxxxxxxxxxxxxxxxxx>]

There should be a retract or takeback command.

Don


   From: Daniel Bump <bump@xxxxxxxxxxxxxxxxx>
   CC: gnugo@xxxxxxxxxxxxxxxxx, drd@xxxxxxxxxxxxxxxxx
   References:  <200107311527.LAA07883@xxxxxxxxxxxxxxxxx>
   Content-Type: text
   Content-Length: 3644


   Don Dailey wrote:

   > First of  all, to answer your  question, what I have implement between
   > my interface and my go program is very  minimal and is just a subset
   > of what is in gnugo:
   > 
   >      black
   >      boardsize,
   >      genmove_black
   >      genmove_white
   >      komi
   >      new_score	
   >      quit
   >      showboard
   >      size
   >      white

   This is almost the same set of commands needed to run twogtp. When
   I added gtp support to GNU Go 2.6 I added the following commands:

       black
       boardsize
       fixed_handicap
       genmove_black
       genmove_white
       help
       komi
       name
       new_score
       quit
       showboard
       version
       white

   > What I would  suggest   is that a    "minimal  set" of  commands   get
   > documented.  A minimal set   would guarantee that your  software works
   > with  anyone elses interface, autoplayer,  etc, and any external tools
   > should be  designed to  work without  trouble using  this set.   There
   > should not be  commands in this set  that require an unusual amount of
   > effort to implement and this should  just include the basic mechanisms
   > of  making moves, taking them back   and reporting starting parameters
   > such as "boardsize."

   What we seem to be close to being able to standardize immediately
   would be a small set of commands that can be obeyed by a Go
   program. 

   The ability to respond to commands is not in itself enough to
   allow two programs to interact without the intervention of a third
   party unless one adds also the ability to issue them. Thus as the
   protocol is currently implemented in GNU Go we cannot (as one does
   using the gmp) cable together two computers by their serial ports
   and expect them to play together without involving a client.

   In order to achieve that, at least one of the two programs
   would have to be able to issue commands as well as to obey
   them. The protocol could be made symmetrical so that the same
   channel is used to issue commands as to recieve them, or the
   protocol could be left asymmetrical. I believe the latter is
   Gunnar's intention but the documentation does not say this
   explicitly.

   In the GMP the same channel is used to reply to commands as to 
   issue them, and there is no clear distinction between a command
   and a reply. In a sense every GMP message is a command. Thus the
   GMP protocol is symmetrical where the GTP as implemented in
   GNU Go and other current examples is not.

   The goal of allowing two computers to play together without a
   third program mediating can still be achieved in the context
   of an asymmetrical protocol if one program assumes the role of
   a teacher (master) and the other that of a student
   (slave). Thus one program issues commands and the other one
   obeys them. They can still play a game.

   Thus to there are three possibilities:

   (1) Play only with the aid of a mediator such as twogtp.

   (2) Add a mode to each program allowing it to issue GTP
   commands as well as to receive them; for a game to commence
   one program is the master, the other the student.

   (3) Try to make the protocol symmetrical like the GMP;

   My guess is that (3) would be a bad decision. My first
   thought was that this means that a GMP/GTP translator is
   not possible but I now think that it actually could be done.

   Leaving aside these problems for another time, the following might
   be a reasonable first set of commands:

   black
   boardsize
   echo
   final_score
   fixed_handicap
   genmove_black
   genmove_white
   help
   is_legal
   komi
   loadsgf
   name
   new_score [but rename this estimate_score]
   prisoners [but rename this captures]
   protocol_version
   quit
   showboard
   version
   white

   A further set of commands useful for a testsuite might
   also be easy to standardize.

   Dan