#! /usr/bin/env python2.7
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
from six.moves import xrange
import adapter
import chess
class GameState (object):
def __init__ (self, board=None):
if board is None:
self.state = chess.Board()
else:
self.state = board.copy()
self.invalidate()
def copy (self):
return GameState(self.state)
def invalidate (self):
self._actions = None
return self
def actions (self):
if self._actions is None:
self._actions = map(adapter.move_to_label_flat, self.state.legal_moves)
return self._actions
def captures_or_evasions (self):
moves = list(self.state.legal_moves)
if not self.state.is_check():
moves = filter(lambda m : self.state.is_capture(m), moves)
return map(adapter.move_to_label_flat, moves)
def parse_action (self, action):
move = adapter.label_flat_to_move(action)
# TODO: Fix this promotion stuff
moving_piece = self.state.piece_at(move.from_square)
if moving_piece.piece_type == chess.PAWN:
rank, _ = adapter.square_to_index(move.to_square)
# If pawn moves to edge promote to queen
if rank == 0 or rank == 7:
move.promotion = chess.QUEEN
return move
def push_action (self, action):
move = self.parse_action(action)
self.state.push(move)
self.invalidate()
return action
def pop_action (self):
move = self.state.pop()
self.invalidate()
return adapter.move_to_label_flat(move)
def observation (self):
return adapter.position_to_hwc(self.state)
def done (self):
return self.state.is_game_over()
def reward (self):
if self.state.is_checkmate():
return -1.0
return 0.0
def turn (self):
return self.state.turn
