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/.freeze
RIGHT = 
/(d|\x1B\[C)\z/.freeze
EXIT = 
/(q|\x03)\z/.freeze

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



68
69
70
71
72
73
74
 
# File 'lib/pgn/game.rb', line 68

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.



57
58
59
 
# File 'lib/pgn/game.rb', line 57

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



56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
 
# File 'lib/pgn/game.rb', line 56

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

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

  # @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
  #
  # Reuse-safety invariant: when an element is already a MoveText we reuse
  # it directly (sharing one object between the parser's move tree and
  # Game#moves) whenever its comment is already fully cleaned. This is safe
  # because nothing mutates a MoveText after this assignment returns. We
  # still re-wrap when the comment carries braces: the parser's single-pass
  # clean_text leaves braces on multi-line/nested comments, and the second
  # clean_text that MoveText.new applies here is load-bearing for those
  # (matches the legacy whittle byte-output). Skipping it would change
  # serialized comments.
  def moves=(moves)
    @moves =
      moves.map do |m|
        if m.is_a?(String)
          MoveText.new(m.include?('0') ? m.gsub('0', 'O') : m)
        elsif m.notation.include?('0')
          MoveText.new(m.notation.gsub('0', 'O'), m.annotation, m.comment, m.variations)
        elsif m.comment.nil? || !m.comment.include?('{')
          m
        else
          MoveText.new(m.notation, m.annotation, m.comment, m.variations)
        end
      end
  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 ||= begin
      position = starting_position
      arr = [position]
      moves.each do |move|
        new_pos = position.move(move.notation)
        arr << new_pos
        position = new_pos
      end
      arr
    end
  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 > 0
      when RIGHT
        index += 1 if index < moves.length
      when EXIT
        break
      end
    end
  end
end

#pgn ⇒ Object

Returns the value of attribute pgn.



57
58
59
 
# File 'lib/pgn/game.rb', line 57

def pgn
  @pgn
end

#result ⇒ String

Returns the outcome of the game.

Examples:

game.result #=> "1-0"

Returns:

  • (String) —

    the outcome of the game



56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
 
# File 'lib/pgn/game.rb', line 56

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

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

  # @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
  #
  # Reuse-safety invariant: when an element is already a MoveText we reuse
  # it directly (sharing one object between the parser's move tree and
  # Game#moves) whenever its comment is already fully cleaned. This is safe
  # because nothing mutates a MoveText after this assignment returns. We
  # still re-wrap when the comment carries braces: the parser's single-pass
  # clean_text leaves braces on multi-line/nested comments, and the second
  # clean_text that MoveText.new applies here is load-bearing for those
  # (matches the legacy whittle byte-output). Skipping it would change
  # serialized comments.
  def moves=(moves)
    @moves =
      moves.map do |m|
        if m.is_a?(String)
          MoveText.new(m.include?('0') ? m.gsub('0', 'O') : m)
        elsif m.notation.include?('0')
          MoveText.new(m.notation.gsub('0', 'O'), m.annotation, m.comment, m.variations)
        elsif m.comment.nil? || !m.comment.include?('{')
          m
        else
          MoveText.new(m.notation, m.annotation, m.comment, m.variations)
        end
      end
  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 ||= begin
      position = starting_position
      arr = [position]
      moves.each do |move|
        new_pos = position.move(move.notation)
        arr << new_pos
        position = new_pos
      end
      arr
    end
  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 > 0
      when RIGHT
        index += 1 if index < moves.length
      when EXIT
        break
      end
    end
  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



56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
 
# File 'lib/pgn/game.rb', line 56

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

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

  # @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
  #
  # Reuse-safety invariant: when an element is already a MoveText we reuse
  # it directly (sharing one object between the parser's move tree and
  # Game#moves) whenever its comment is already fully cleaned. This is safe
  # because nothing mutates a MoveText after this assignment returns. We
  # still re-wrap when the comment carries braces: the parser's single-pass
  # clean_text leaves braces on multi-line/nested comments, and the second
  # clean_text that MoveText.new applies here is load-bearing for those
  # (matches the legacy whittle byte-output). Skipping it would change
  # serialized comments.
  def moves=(moves)
    @moves =
      moves.map do |m|
        if m.is_a?(String)
          MoveText.new(m.include?('0') ? m.gsub('0', 'O') : m)
        elsif m.notation.include?('0')
          MoveText.new(m.notation.gsub('0', 'O'), m.annotation, m.comment, m.variations)
        elsif m.comment.nil? || !m.comment.include?('{')
          m
        else
          MoveText.new(m.notation, m.annotation, m.comment, m.variations)
        end
      end
  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 ||= begin
      position = starting_position
      arr = [position]
      moves.each do |move|
        new_pos = position.move(move.notation)
        arr << new_pos
        position = new_pos
      end
      arr
    end
  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 > 0
      when RIGHT
        index += 1 if index < moves.length
      when EXIT
        break
      end
    end
  end
end

Instance Method Details

#fen_list ⇒ Array<String>

Returns list of the fen representations of the positions.

Returns:

  • (Array<String>) —

    list of the fen representations of the positions



140
141
142
 
# File 'lib/pgn/game.rb', line 140

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

#initial_fen ⇒ Object 



111
112
113
 
# File 'lib/pgn/game.rb', line 111

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.



148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
 
# File 'lib/pgn/game.rb', line 148

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 > 0
    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:



125
126
127
128
129
130
131
132
133
134
135
136
 
# File 'lib/pgn/game.rb', line 125

def positions
  @positions ||= begin
    position = starting_position
    arr = [position]
    moves.each do |move|
      new_pos = position.move(move.notation)
      arr << new_pos
      position = new_pos
    end
    arr
  end
end

#starting_position ⇒ Object 



115
116
117
118
119
120
121
 
# File 'lib/pgn/game.rb', line 115

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.



107
108
109
 
# File 'lib/pgn/game.rb', line 107

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