lib/games/state_base.rb

   1 # Copyright (c) 2009 Paolo Capriotti <p.capriotti@gmail.com>
   2 #
   3 # This program is free software; you can redistribute it and/or modify
   4 # it under the terms of the GNU General Public License as published by
   5 # the Free Software Foundation; either version 2 of the License, or
   6 # (at your option) any later version.
   7
   8 class StateBase
   9   attr_accessor :turn
  10   attr_accessor :board
  11   attr_reader :move_factory, :piece_factory
  12
  13   def initialize(board, move_factory, piece_factory)
  14     @board = board
  15     @move_factory = move_factory
  16     @piece_factory = piece_factory
  17   end
  18
  19   def initialize_copy(other)
  20     @board = other.board.dup
  21   end
  22
  23   def try(move)
  24     tmp = dup
  25     tmp.perform! move
  26     yield tmp
  27   end
  28
  29   def basic_move(move)
  30     captured = @board[move.dst]
  31     @board[move.dst] = @board[move.src]
  32     @board[move.src] = nil
  33     captured
  34   end
  35
  36   def promote_on!(p, type)
  37     if @board[p]
  38       @board[p] = piece_factory.new(@board[p].color, type)
  39     end
  40   end
  41
  42   def to_s
  43     [@board.to_s,
  44      "turn #{@turn.to_s}"].join("\n")
  45   end
  46
  47   def ==(other)
  48     @board == other.board &&
  49       @turn == other.turn
  50   end
  51 end