[gtp] Mark Boon's proposed additions to GTP

Mark Boon proposed number of additions to GTP commands. The original post can be found here: http://computer-go.org/pipermail/computer-go/2006-March/004962.html

First, some of his commands have "vertex color" as arguments or output, but GTP 2 already defines syntactic entity "move" for this purpose, but in different order, "color vertex". Therefore I think new commands should use "move" instead.

Specification for "last_move" command was repeated 3 times. I suspect copy and paste error.

As GNU Go already implements "is_legal" and "last_move" as its private commands, it would be worthwhile to look at them. Currently:

# is_legal arguments: move effects: none output: 1 if the move is legal, 0 if it is not (int) fails: invalid color or coordinate

My comments: GNU Go should return boolean for this instead of int?

# last_move arguments: none effects: none output: the last move (move) fails: no previous move known

Compared to Mark Boon's original proposal, it prints color before vertex, consistent with other GTP commands, and specifies failure conditions.

Seo Sanghyeon