如何使用Hashes在Ruby中存储方法?

时间:2013-07-13 19:01:05

标签: ruby class methods hash

我想知道是否有人可以向我解释为什么我无法使用Hash($player_x_command_list)访问我的player_x_move(position)方法?这样做的正确方法是什么?

我要做的是,创建一个Hash,让用户输入输入,并反映回我班级的方法。

我尝试了各种改变方法,以便代码可以正常工作,但没有任何作用。

我收到了错误:

  游戏的未定义方法`player_x_move':Class(NoMethodError)

这是否意味着哈希无法存储方法?

这是我的代码:

#Tic Tac Toe Game
#The format is the below: where index 0 represents top left and index 8 represents bottom right
#goes 0,1,2
#     3,4,5
#     6,7,8
#"e" is for empty. "x" is for Player X moves and "o" is for Player O moves



class Game
  @@player_x_win_count = 0
  @@player_o_win_count = 0

  def initialize
    @board = Array.new(9, "e")
    @move_number = 0
  end

  def get_names
  puts "Hi Welcome to my Tic Tac Toe Game. The board looks like this:

  |TL|TM|TR|
  |ML|MM|MR|
  |BL|BM|BR|

  Each position of the Tic Tac Toe board is represented by two letters. To \"X\" or \"O\" a position, just input the two letters in CAPS like \"MM\"


  The command list is as follows:
  TL = top left
  TM = top mid
  TR = top right
  ML = mid left
  MM = mid mid
  MR = mid right
  BL = bottom left
  BM = bottom mid
  BR = bottom right
  board = to view the board
  new game = to clean the board and create a new game (note that this command should only be used when you don't want to continue on the current game. The game automatically creates a new game if a winner, loser, or draw is declared)
   "
    puts "Please Enter PlayerX's name. He/she will be using X's to mark the board."
    @player_x = gets.chomp

    puts "Please Enter PlayerO's name. He/she will be using O's to mark the board."
    @player_o = gets.chomp

    self.new_round
  end

$player_x_command_list = {"TL" => self.player_x_move(0), "TM" => self.player_x_move(1), "TR" => self.player_x_move(2), "ML" => self.player_x_move(3), "MM" => self.player_x_move(4), 
    "MR" => self.player_x_move(5), "BL" => self.player_x_move(6), "BM" => self.player_x_move(7), "BR" => self.player_x_move(8), "board" => self.board, "new game" => self.clean_board, 
    "win count" => self.win_count}

$player_o_command_list = {"TL" => self.player_o_move(0), "TM" => self.player_o_move(1), "TR" => self.player_o_move(2), "ML" => self.player_o_move(3), "MM" => self.player_o_move(4), 
    "MR" => self.player_o_move(5), "BL" => self.player_o_move(6), "BM" => self.player_o_move(7), "BR" => self.player_o_move(8), "board" => self.board, "new game" => self.clean_board, 
    "win count" => self.win_count}


  def enter_command_player_x
    puts "Please input your command, #{@player_x} aka PlayerX"
    command = gets.chomp
    $player_x_command_list[command]
  end

  def enter_command_player_o
    puts "Please input your command, #{@player_o} aka PlayerY. Type \"help\" to see a full list of commands"
    command = gets.chomp
    $player_o_command_list[command]
  end


  def new_round
    puts "So who wants to go first this round"
    went_first_this_round = gets.chomp
    if went_first_this_round == @player_x
      self.enter_command_player_x
    elsif went_first_this_round == @player_o
      self.enter_command_player_o
    else
      puts "Not a valid name. Please enter one of the player's names"
    end
  end

  def board
    print "|#{@board[0]}|#{@board[1]}|#{@board[2]}|\n|#{@board[3]}|#{@board[4]}|#{@board[5]}|\n|#{@board[6]}|#{@board[7]}|#{@board[8]}|"
  end

  def player_x_move(position)
    if @board[position] == "x" || @board[position] == "o"  
      return "That move was invalid as someone has already moved there. Please enter a valid move"
    end
    @board[position] = "x"
    @move_number += 1
    puts "That was move number #{@move_number} and the current board looks like: " 
    self.board
    self.check_game
    puts "Now it is #{player_o}'s turn. #{player_o} please input your next command."
    self.enter_command_player_o
  end

  def player_o_move(position)
    if @board[position] == "x" || @board[position] == "o"     
      return "That move was invalid as someone has already moved there. Please enter a valid move"
    end
    @board[position] = "o"
    @move_number += 1
    puts "That was move number #{@move_number} and the current board looks like: "
    self.board
    self.check_game
    puts "Now it is #{player_x}'s turn. #{player_x} please input your next command"
    self.enter_command_player_x
  end

  def check_game
    triple_x = "xxx"
    triple_o = "ooo"
    if @move_number == 9
      @move_number = 0
      self.clean_board
      return "The board is completely filled up. Looks like this is a draw. This is Game Over. Make a new game by setting any variable = to new.Game and using that variable to play"
    elsif @board[0] + @board[1] + @board[2] == triple_x
      @@player_x_win_count += 1
      @move_number = 0
      self.clean_board
      return "Player X Wins"
    elsif @board[3] + @board[4] + @board[5] == triple_x
      @@player_x_win_count += 1
      @move_number = 0
      self.clean_board
      return "Player X Wins"
    elsif @board[6] + @board[7] + @board[8] == triple_x
      @@player_x_win_count += 1
      @move_number = 0
      self.clean_board
      return "Player X Wins"
    elsif @board[0] + @board[3] + @board[6] == triple_x
      @@player_x_win_count += 1
      @move_number = 0
      self.clean_board
      return "Player X Wins"
    elsif @board[1] + @board[4] + @board[7] == triple_x
      @@player_x_win_count += 1
      @move_number = 0
      self.clean_board
      return "Player X Wins"
    elsif @board[2] + @board[5] + @board[8] == triple_x
      @@player_x_win_count += 1
      @move_number = 0
      self.clean_board
      return "Player X Wins"
    elsif @board[0] + @board[4] + @board[8] == triple_x
      @@player_x_win_count += 1
      @move_number = 0
      self.clean_board
      return "Player X Wins"
    elsif @board[2] + @board[4] + @board[6] == triple_x
      @@player_x_win_count += 1
      @move_number = 0
      self.clean_board
      return "Player X Wins"
    #now check if Player O Wins
    elsif @board[0] + @board[1] + @board[2] == triple_o
      @@player_y_win_count += 1
      @move_number = 0
      self.clean_board
      return "Player O Wins"
    elsif @board[3] + @board[4] + @board[5] == triple_o
      @@player_y_win_count += 1
      @move_number = 0
      self.clean_board
      return "Player O Wins"   
    elsif @board[6] + @board[7] + @board[8] == triple_o
      @@player_y_win_count += 1
      @move_number = 0
      self.clean_board
      return "Player O Wins"   
    elsif @board[0] + @board[3] + @board[6] == triple_o
      @@player_y_win_count += 1
      @move_number = 0
      self.clean_board
      return "Player O Wins"    
    elsif @board[1] + @board[4] + @board[7] == triple_o
      @@player_y_win_count += 1
      @move_number = 0
      self.clean_board
      return "Player O Wins"   
    elsif @board[2] + @board[5] + @board[8] == triple_o
      @@player_y_win_count += 1
      @move_number = 0
      self.clean_board
      return "Player O Wins"  
    elsif @board[0] + @board[4] + @board[8] == triple_o
      @@player_y_win_count += 1
      @move_number = 0
      self.clean_board
      return "Player O Wins" 
    elsif @board[2] + @board[4] + @board[6] == triple_o
      @@player_y_win_count += 1
      @move_number = 0
      self.clean_board
      return "Player O Wins"   
    else
      return "no one has WON YET! Continue your GAME!!"
    end
  end

  def clean_board
    @board = Array.new(9, "e")
  end

  def win_count
    puts "So far Player X has won #{@@player_x_win_count} times and Player O has won #{@@player_o_win_count} times."
  end

end

a = Game.new
a.get_names

2 个答案:

答案 0 :(得分:4)

这里有一些问题:

  1. 你的范围是错误的。定义哈希时,self是类,而不是您要操作的类的实例。
  2. 当您创建哈希时,哈希的值将是player_x_move等方法在定义时的返回值
  3. 您可以使用case来简化此操作。

    def enter_command
      puts "Please input your command, #{@player_x} aka PlayerX"
      command = gets.chomp
      case command
      when "TL"
        player_x_move(0)
      when "TM"
        player_x_move(1)
      # etc
      else
        puts "#{command} is not a valid command."
      end
    end
    

    您还可以通过创建接受enter_commandplayer_move等参数的方法,然后通过播放器对其进行操作来进一步简化代码。这可以防止您必须为每个玩家复制每个方法。

    您可以考虑的其他事情只是根据给定的命令查找移动的索引:

    COMMAND_POSITIONS = %w(TL TM TR ML MM MR BL BM BR)
    def enter_command(player)
      puts "Please input your command, #{player}"
      command = gets.chomp
      case command
      when *COMMAND_POSITIONS
        player_move player, COMMAND_POSITIONS.index(command)
      when "board"
        board
      when "new game"
        clean_board
      when "win count"
        win_count
      else
        puts "#{command}" is not a valid command
      end
    end
    

答案 1 :(得分:3)

哈希无法存储方法。方法不是对象,但可以转换为Procs。方法定义返回nil changed since this writing 。但是,您可以存储Proc或lambda。您还可以存储方法的返回(评估)。

以下是如何将Proc存储到方法中派生的Hash的示例。

>> def hello(name)
>>   "Hello #{name}!"
>> end
=> nil
>> my_stored_methods = {:hello => method(:hello).to_proc} 
=> {:hello=>#<Proc:0x816f604 (lambda)>}
>> my_stored_methods[:hello].call("World")
=> "Hello World!"

不要让我调用哈希“my_stored_methods”的stroop效果让你相信实际存在一个真正的方法。它是存储在散列中的lambda(专用Proc),并在适当时使用。实际上,如果我没有在那里使用.to_proc,那么它将保存一个Method实例。

此外,这个解决方案不会随着open方法的发展而增长,如果方法要改变,存储在哈希中的Proc将继续工作,因为方法在将方法存储为Proc时的方式

正如@AndrewMarshall提醒我的那样,我可以把它作为一个Method实例。这仍然不会“存储”方法本身,因为当方法更改时,结果仍将是源方法的历史行为,就像存储时一样。它还提供了更强的“Stroop效果”,因为您可能会错误地认为实际方法存储在那里。它根本就不是。