Class: PGN::Game

Inherits:
Object
  • Object
show all
Defined in:
lib/pgn/game.rb

Overview

Game holds all of the information about a game. It is either the result of parsing a PGN file, or created by hand.

A Game has an interactive #play method, and can also return a list of positions in Position format or FEN.

Constant Summary collapse

LEFT = 
/(a|\x1B\[D)\z/
RIGHT = 
/(d|\x1B\[C)\z/
EXIT = 
/(q|\x03)\z/

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(moves, tags = nil, result = nil, pgn = nil, comment = nil) ⇒ Game

Returns a new instance of Game.

Parameters:

  • moves (Array<String>) —

    a list of moves in SAN

  • tags (Hash<String, String>) (defaults to: nil) —

    metadata about the game

  • result (String) (defaults to: nil) —

    the outcome of the game



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# File 'lib/pgn/game.rb', line 73

def initialize(moves, tags = nil, result = nil, pgn = nil, comment = nil)
  self.moves   = moves
  self.tags    = tags
  self.result  = result
  self.pgn     = pgn
  self.comment = comment
end

Instance Attribute Details

#comment ⇒ Object

Returns the value of attribute comment.



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# File 'lib/pgn/game.rb', line 62

def comment
  @comment
end

#moves ⇒ Array<String>

Returns a list of the moves in standard algebraic notation.

Examples:

game.moves #=> ["e4", "c5", "Nf3", "d6", "d4", "cxd4"]

Returns:

  • (Array<String>) —

    a list of the moves in standard algebraic notation



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# File 'lib/pgn/game.rb', line 61

class Game
  attr_accessor :tags, :result, :pgn, :comment
  attr_reader :moves

  LEFT  = /(a|\x1B\[D)\z/
  RIGHT = /(d|\x1B\[C)\z/
  EXIT  = /(q|\x03)\z/

  # @param moves [Array<String>] a list of moves in SAN
  # @param tags [Hash<String, String>] metadata about the game
  # @param result [String] the outcome of the game
  #
  def initialize(moves, tags = nil, result = nil, pgn = nil, comment = nil)
    self.moves   = moves
    self.tags    = tags
    self.result  = result
    self.pgn     = pgn
    self.comment = comment
  end

  # @param moves [Array<String>] a list of moves in SAN
  #
  # Standardize castling moves to use O's instead of 0's
  #
  def moves=(moves)
    @moves = moves.map { |m| standardize_castling(m) }
  end

  # @return [String] a canonical PGN string for this game, ending with a
  #   trailing newline.
  #
  def to_pgn
    PGN::Serializer.new(self).to_s
  end

  def initial_fen
    tags && tags['FEN']
  end

  def starting_position
    @starting_position ||= if initial_fen
                             PGN::FEN.new(initial_fen).to_position
                           else
                             PGN::Position.start
                           end
  end

  # @return [Array<PGN::Position>] list of the {PGN::Position}s in the game
  #
  def positions
    @positions ||= each_position.to_a
  end

  # @return [Enumerator, self] with a block: yields each {PGN::Position}
  #   in order (starting position, then one per move) and returns self.
  #   Without a block: returns an Enumerator that yields the same.
  #
  # The replay loop is shared with {#positions} so eager and lazy paths
  # produce identical position objects in identical order.
  def each_position
    return enum_for(:each_position) unless block_given?

    position = starting_position
    yield position
    moves.each do |move|
      position = position.move(move.notation)
      yield position
    end
    self
  end

  # @return [Array<String>] list of the fen representations of the positions
  #
  def fen_list
    positions.map { |p| p.to_fen.inspect }
  end

  # Interactively step through the game
  #
  # Use +d+ to move forward, +a+ to move backward, and +^C+ to exit.
  #
  def play
    index = 0
    hist = Array.new(3, '')

    loop do
      puts "\e[H\e[2J"
      puts positions[index].inspect
      hist[0..2] = (hist[1..2] << $stdin.getch)

      case hist.join
      when LEFT
        index -= 1 if index.positive?
      when RIGHT
        index += 1 if index < moves.length
      when EXIT
        break
      end
    end
  end

  private

  # A MoveText is reused as-is (no new object) when its notation needs no
  # '0'->'O' fix and its comment has no braces left to clean; a braced
  # comment still needs MoveText.new's second clean_text pass to match the
  # legacy whittle byte-output.
  def standardize_castling(entry)
    return MoveText.new(entry.include?('0') ? entry.gsub('0', 'O') : entry) if entry.is_a?(String)

    notation = entry.notation.include?('0') ? entry.notation.gsub('0', 'O') : entry.notation
    return entry if notation.equal?(entry.notation) && (entry.comment.nil? || !entry.comment.include?('{'))

    MoveText.new(notation, entry.annotation, entry.comment, entry.variations)
  end
end

#pgn ⇒ Object

Returns the value of attribute pgn.



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# File 'lib/pgn/game.rb', line 62

def pgn
  @pgn
end

#result ⇒ String

Returns the outcome of the game.

Examples:

game.result #=> "1-0"

Returns:

  • (String) —

    the outcome of the game



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# File 'lib/pgn/game.rb', line 61

class Game
  attr_accessor :tags, :result, :pgn, :comment
  attr_reader :moves

  LEFT  = /(a|\x1B\[D)\z/
  RIGHT = /(d|\x1B\[C)\z/
  EXIT  = /(q|\x03)\z/

  # @param moves [Array<String>] a list of moves in SAN
  # @param tags [Hash<String, String>] metadata about the game
  # @param result [String] the outcome of the game
  #
  def initialize(moves, tags = nil, result = nil, pgn = nil, comment = nil)
    self.moves   = moves
    self.tags    = tags
    self.result  = result
    self.pgn     = pgn
    self.comment = comment
  end

  # @param moves [Array<String>] a list of moves in SAN
  #
  # Standardize castling moves to use O's instead of 0's
  #
  def moves=(moves)
    @moves = moves.map { |m| standardize_castling(m) }
  end

  # @return [String] a canonical PGN string for this game, ending with a
  #   trailing newline.
  #
  def to_pgn
    PGN::Serializer.new(self).to_s
  end

  def initial_fen
    tags && tags['FEN']
  end

  def starting_position
    @starting_position ||= if initial_fen
                             PGN::FEN.new(initial_fen).to_position
                           else
                             PGN::Position.start
                           end
  end

  # @return [Array<PGN::Position>] list of the {PGN::Position}s in the game
  #
  def positions
    @positions ||= each_position.to_a
  end

  # @return [Enumerator, self] with a block: yields each {PGN::Position}
  #   in order (starting position, then one per move) and returns self.
  #   Without a block: returns an Enumerator that yields the same.
  #
  # The replay loop is shared with {#positions} so eager and lazy paths
  # produce identical position objects in identical order.
  def each_position
    return enum_for(:each_position) unless block_given?

    position = starting_position
    yield position
    moves.each do |move|
      position = position.move(move.notation)
      yield position
    end
    self
  end

  # @return [Array<String>] list of the fen representations of the positions
  #
  def fen_list
    positions.map { |p| p.to_fen.inspect }
  end

  # Interactively step through the game
  #
  # Use +d+ to move forward, +a+ to move backward, and +^C+ to exit.
  #
  def play
    index = 0
    hist = Array.new(3, '')

    loop do
      puts "\e[H\e[2J"
      puts positions[index].inspect
      hist[0..2] = (hist[1..2] << $stdin.getch)

      case hist.join
      when LEFT
        index -= 1 if index.positive?
      when RIGHT
        index += 1 if index < moves.length
      when EXIT
        break
      end
    end
  end

  private

  # A MoveText is reused as-is (no new object) when its notation needs no
  # '0'->'O' fix and its comment has no braces left to clean; a braced
  # comment still needs MoveText.new's second clean_text pass to match the
  # legacy whittle byte-output.
  def standardize_castling(entry)
    return MoveText.new(entry.include?('0') ? entry.gsub('0', 'O') : entry) if entry.is_a?(String)

    notation = entry.notation.include?('0') ? entry.notation.gsub('0', 'O') : entry.notation
    return entry if notation.equal?(entry.notation) && (entry.comment.nil? || !entry.comment.include?('{'))

    MoveText.new(notation, entry.annotation, entry.comment, entry.variations)
  end
end

#tags ⇒ Hash<String, String>

Returns metadata about the game.

Examples:

game.tags #=> {"White" => "Kasparov", "Black" => "Deep Blue"}

Returns:

  • (Hash<String, String>) —

    metadata about the game



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# File 'lib/pgn/game.rb', line 61

class Game
  attr_accessor :tags, :result, :pgn, :comment
  attr_reader :moves

  LEFT  = /(a|\x1B\[D)\z/
  RIGHT = /(d|\x1B\[C)\z/
  EXIT  = /(q|\x03)\z/

  # @param moves [Array<String>] a list of moves in SAN
  # @param tags [Hash<String, String>] metadata about the game
  # @param result [String] the outcome of the game
  #
  def initialize(moves, tags = nil, result = nil, pgn = nil, comment = nil)
    self.moves   = moves
    self.tags    = tags
    self.result  = result
    self.pgn     = pgn
    self.comment = comment
  end

  # @param moves [Array<String>] a list of moves in SAN
  #
  # Standardize castling moves to use O's instead of 0's
  #
  def moves=(moves)
    @moves = moves.map { |m| standardize_castling(m) }
  end

  # @return [String] a canonical PGN string for this game, ending with a
  #   trailing newline.
  #
  def to_pgn
    PGN::Serializer.new(self).to_s
  end

  def initial_fen
    tags && tags['FEN']
  end

  def starting_position
    @starting_position ||= if initial_fen
                             PGN::FEN.new(initial_fen).to_position
                           else
                             PGN::Position.start
                           end
  end

  # @return [Array<PGN::Position>] list of the {PGN::Position}s in the game
  #
  def positions
    @positions ||= each_position.to_a
  end

  # @return [Enumerator, self] with a block: yields each {PGN::Position}
  #   in order (starting position, then one per move) and returns self.
  #   Without a block: returns an Enumerator that yields the same.
  #
  # The replay loop is shared with {#positions} so eager and lazy paths
  # produce identical position objects in identical order.
  def each_position
    return enum_for(:each_position) unless block_given?

    position = starting_position
    yield position
    moves.each do |move|
      position = position.move(move.notation)
      yield position
    end
    self
  end

  # @return [Array<String>] list of the fen representations of the positions
  #
  def fen_list
    positions.map { |p| p.to_fen.inspect }
  end

  # Interactively step through the game
  #
  # Use +d+ to move forward, +a+ to move backward, and +^C+ to exit.
  #
  def play
    index = 0
    hist = Array.new(3, '')

    loop do
      puts "\e[H\e[2J"
      puts positions[index].inspect
      hist[0..2] = (hist[1..2] << $stdin.getch)

      case hist.join
      when LEFT
        index -= 1 if index.positive?
      when RIGHT
        index += 1 if index < moves.length
      when EXIT
        break
      end
    end
  end

  private

  # A MoveText is reused as-is (no new object) when its notation needs no
  # '0'->'O' fix and its comment has no braces left to clean; a braced
  # comment still needs MoveText.new's second clean_text pass to match the
  # legacy whittle byte-output.
  def standardize_castling(entry)
    return MoveText.new(entry.include?('0') ? entry.gsub('0', 'O') : entry) if entry.is_a?(String)

    notation = entry.notation.include?('0') ? entry.notation.gsub('0', 'O') : entry.notation
    return entry if notation.equal?(entry.notation) && (entry.comment.nil? || !entry.comment.include?('{'))

    MoveText.new(notation, entry.annotation, entry.comment, entry.variations)
  end
end

Instance Method Details

#each_position {|position| ... } ⇒ Enumerator, self

The replay loop is shared with #positions so eager and lazy paths produce identical position objects in identical order.

Yields:

  • (position)

Returns:

  • (Enumerator, self) —

    with a block: yields each Position in order (starting position, then one per move) and returns self. Without a block: returns an Enumerator that yields the same.



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# File 'lib/pgn/game.rb', line 120

def each_position
  return enum_for(:each_position) unless block_given?

  position = starting_position
  yield position
  moves.each do |move|
    position = position.move(move.notation)
    yield position
  end
  self
end

#fen_list ⇒ Array<String>

Returns list of the fen representations of the positions.

Returns:

  • (Array<String>) —

    list of the fen representations of the positions



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# File 'lib/pgn/game.rb', line 134

def fen_list
  positions.map { |p| p.to_fen.inspect }
end

#initial_fen ⇒ Object 



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# File 'lib/pgn/game.rb', line 96

def initial_fen
  tags && tags['FEN']
end

#play ⇒ Object

Interactively step through the game

Use d to move forward, a to move backward, and ^C to exit.



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# File 'lib/pgn/game.rb', line 142

def play
  index = 0
  hist = Array.new(3, '')

  loop do
    puts "\e[H\e[2J"
    puts positions[index].inspect
    hist[0..2] = (hist[1..2] << $stdin.getch)

    case hist.join
    when LEFT
      index -= 1 if index.positive?
    when RIGHT
      index += 1 if index < moves.length
    when EXIT
      break
    end
  end
end

#positions ⇒ Array<PGN::Position>

Returns list of the Positions in the game.

Returns:



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# File 'lib/pgn/game.rb', line 110

def positions
  @positions ||= each_position.to_a
end

#starting_position ⇒ Object 



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# File 'lib/pgn/game.rb', line 100

def starting_position
  @starting_position ||= if initial_fen
                           PGN::FEN.new(initial_fen).to_position
                         else
                           PGN::Position.start
                         end
end

#to_pgn ⇒ String

Returns a canonical PGN string for this game, ending with a trailing newline.

Returns:

  • (String) —

    a canonical PGN string for this game, ending with a trailing newline.



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# File 'lib/pgn/game.rb', line 92

def to_pgn
  PGN::Serializer.new(self).to_s
end