Class: Pgn2Fen::Game

Inherits:
Object
  • Object
show all
Defined in:
lib/pgn2fen.rb

Constant Summary collapse

START_FEN =

constants

"rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"
HEADER_KEY_REGEX = 
/^\[([A-Z][A-Za-z]*)\s.*\]$/
HEADER_VALUE_REGEX = 
/^\[[A-Za-z]+\s"(.*)"\]$/
OPEN_PAREN = 
"("
CLOSE_PAREN = 
")"
OPEN_BRACE = 
"{"
CLOSE_BRACE = 
"}"
@@pgn_squares =

static initializers

["a8","b8","c8","d8","e8","f8","g8","h8","a7","b7","c7","d7","e7","f7","g7","h7","a6","b6","c6","d6","e6","f6","g6","h6","a5","b5","c5","d5","e5","f5","g5","h5","a4","b4","c4","d4","e4","f4","g4","h4","a3","b3","c3","d3","e3","f3","g3","h3","a2","b2","c2","d2","e2","f2","g2","h2","a1","b1","c1","d1","e1","f1","g1","h1"]
@@number_squares = 
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63]
@@pgn_number_hash = 

      
        
@@number_pgn_hash =
          
        

        

      
        
@@aFile =
          
        

        
Set.new


      
        
@@bFile =
          
        

        
Set.new


      
        
@@cFile =
          
        

        
Set.new


      
        
@@dFile =
          
        

        
Set.new


      
        
@@eFile =
          
        

        
Set.new


      
        
@@fFile =
          
        

        
Set.new


      
        
@@gFile =
          
        

        
Set.new


      
        
@@hFile =
          
        

        
Set.new


      
        
@@firstRank =
          
        

        
Set.new


      
        
@@secondRank =
          
        

        
Set.new


      
        
@@thirdRank =
          
        

        
Set.new


      
        
@@fourthRank =
          
        

        
Set.new


      
        
@@fifthRank =
          
        

        
Set.new


      
        
@@sixthRank =
          
        

        
Set.new


      
        
@@seventhRank =
          
        

        
Set.new


      
        
@@eighthRank =
          
        

        
Set.new


      
        
@@light_squares =
          
        

        
Set.new


      
        
@@dark_squares =
          
        

        
Set.new


      
        
@@one_thru_eight =
          
        

        
Set.new


      
        
@@a_thru_h =
          
        

        
Set.new


      
    

  




  
Instance Attribute Summary collapse

  




  
    

      Instance Method Summary
      collapse
    


    
  



  
Constructor Details

  
    

  

  
    #initialize(pgn_data)  ⇒ Game 
  

  

  




  

    

Returns a new instance of Game.



  





  



  

    
      


98
99
100
101
102
103
104
105
106
107
108
109

    		
    
      
# File 'lib/pgn2fen.rb', line 98

def initialize(pgn_data)
  @pgn_data = pgn_data
  @board = []
  @board_start_fen = START_FEN
  @fen = nil
  @potential_enpassent_ply = nil
  @halfmove = 0
  @fullmove = 1
  @promotion = false
  @promotion_piece = nil
  @board_color_from_fen = nil
end


    		
  





  



  

    
Instance Attribute Details

    
      
      
      

  

  
    #board_color_from_fen  ⇒ Object 
  

  

  




  

    

Returns the value of attribute board_color_from_fen.



  





  



  

    
      


19
20
21

    		
    
      
# File 'lib/pgn2fen.rb', line 19

def board_color_from_fen
  @board_color_from_fen
end


    		
  





    
      
      
      

  

  
    #can_black_castle_kingside  ⇒ Object 
  

  

  




  

    

Returns the value of attribute can_black_castle_kingside.



  





  



  

    
      


19
20
21

    		
    
      
# File 'lib/pgn2fen.rb', line 19

def can_black_castle_kingside
  @can_black_castle_kingside
end


    		
  





    
      
      
      

  

  
    #can_black_castle_queenside  ⇒ Object 
  

  

  




  

    

Returns the value of attribute can_black_castle_queenside.



  





  



  

    
      


19
20
21

    		
    
      
# File 'lib/pgn2fen.rb', line 19

def can_black_castle_queenside
  @can_black_castle_queenside
end


    		
  





    
      
      
      

  

  
    #can_white_castle_kingside  ⇒ Object 
  

  

  




  

    

Returns the value of attribute can_white_castle_kingside.



  





  



  

    
      


19
20
21

    		
    
      
# File 'lib/pgn2fen.rb', line 19

def can_white_castle_kingside
  @can_white_castle_kingside
end


    		
  





    
      
      
      

  

  
    #fen_array  ⇒ Object 
  

  

  




  

    

attr_accessor :event, :site, :date, :eventdate, :round, :white, :black, :whiteelo, :blackelo, :result, :eco, :plycount, :fen



  





  



  

    
      


18
19
20

    		
    
      
# File 'lib/pgn2fen.rb', line 18

def fen_array
  @fen_array
end


    		
  





    
      
      
      

  

  
    #fullmove  ⇒ Object 
  

  

  




  

    

Returns the value of attribute fullmove.



  





  



  

    
      


19
20
21

    		
    
      
# File 'lib/pgn2fen.rb', line 19

def fullmove
  @fullmove
end


    		
  





    
      
      
      

  

  
    #halfmove  ⇒ Object 
  

  

  




  

    

Returns the value of attribute halfmove.



  





  



  

    
      


19
20
21

    		
    
      
# File 'lib/pgn2fen.rb', line 19

def halfmove
  @halfmove
end


    		
  





    
      
      
      

  

  
    #pgn  ⇒ Object 
  

  

  




  

    

attr_accessor :event, :site, :date, :eventdate, :round, :white, :black, :whiteelo, :blackelo, :result, :eco, :plycount, :fen



  





  



  

    
      


18
19
20

    		
    
      
# File 'lib/pgn2fen.rb', line 18

def pgn
  @pgn
end


    		
  





    
      
      
      

  

  
    #potential_enpassent_ply  ⇒ Object 
  

  

  




  

    

Returns the value of attribute potential_enpassent_ply.



  





  



  

    
      


19
20
21

    		
    
      
# File 'lib/pgn2fen.rb', line 19

def potential_enpassent_ply
  @potential_enpassent_ply
end


    		
  





    
      
      
      

  

  
    #promotion  ⇒ Object 
  

  

  




  

    

Returns the value of attribute promotion.



  





  



  

    
      


19
20
21

    		
    
      
# File 'lib/pgn2fen.rb', line 19

def promotion
  @promotion
end


    		
  





    
      
      
      

  

  
    #promotion_piece  ⇒ Object 
  

  

  




  

    

Returns the value of attribute promotion_piece.



  





  



  

    
      


19
20
21

    		
    
      
# File 'lib/pgn2fen.rb', line 19

def promotion_piece
  @promotion_piece
end


    		
  





    
  



  

    
Instance Method Details


    
      

  

  
    #board_to_fen  ⇒ Object 
  

  

  




  

    

return fen representation from board



  





  



  

    
      


514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541

    		
    
      
# File 'lib/pgn2fen.rb', line 514

def board_to_fen
  fen = ""
  empty_square_counter = 0;
  @board.each_with_index { |tok, idx|
    if (idx % 8 == 0 && idx > 0)
      if empty_square_counter != 0
        fen.concat(empty_square_counter.to_s)
        empty_square_counter = 0
      end
      fen.concat("/")
    end
    if tok.empty?
      empty_square_counter = empty_square_counter + 1
    else
      if empty_square_counter != 0
        fen.concat(empty_square_counter.to_s)
        empty_square_counter = 0
      end
      fen.concat(tok)
    end
  }
  # last squares could be empty
  if empty_square_counter != 0
    fen.concat(empty_square_counter.to_s)
    empty_square_counter = 0
  end
  fen
end


    		
  





    
      

  

  
    #clean_comments(pgn)  ⇒ Object 
  

  

  




  

    
      


347
348
349

    		
    
      
# File 'lib/pgn2fen.rb', line 347

def clean_comments(pgn)
  remove_text_between_tokens_inclusive(pgn, OPEN_BRACE, CLOSE_BRACE)
end


    		
  





    
      

  

  
    #clean_pgn(pgn)  ⇒ Object 
  

  

  




  

    

clean pgn - remove comments and other unrequired text



  





  



  

    
      


331
332
333
334
335
336
337
338
339
340
341
342
343
344
345

    		
    
      
# File 'lib/pgn2fen.rb', line 331

def clean_pgn(pgn)
  pgn.strip!
  # clean result
  pgn.sub!("1-0", ""); pgn.sub!("0-1", ""); pgn.sub!("1/2-1/2", "")
  # clean mate and incomplete game marker
  pgn.gsub!("#", ""); pgn.gsub!("*", "")
  #remove all chessbase $ characters
  pgn.gsub!(/\$(\w+)/, "")
  #remove all comments - content within {}
  #pgn.gsub!(/(\{[^}]+\})+?/, "")
  pgn = clean_comments(pgn)
  #remove all subvariations - content within ()
  #pgn.gsub!(/(\([^}]+\))+?/, "")
  pgn = clean_subvariations(pgn)
end


    		
  





    
      

  

  
    #clean_subvariations(pgn)  ⇒ Object 
  

  

  




  

    
      


351
352
353

    		
    
      
# File 'lib/pgn2fen.rb', line 351

def clean_subvariations(pgn)
  remove_text_between_tokens_inclusive(pgn, OPEN_PAREN, CLOSE_PAREN)
end


    		
  





    
      

  

  
    #dark_square_by_number(square_number)  ⇒ Object 
  

  

  




  

    
      


257
258
259

    		
    
      
# File 'lib/pgn2fen.rb', line 257

def dark_square_by_number square_number
  @@dark_squares.include?(square_number)
end


    		
  





    
      

  

  
    #dark_square_by_pgn(square_pgn)  ⇒ Object 
  

  

  




  

    
      


249
250
251

    		
    
      
# File 'lib/pgn2fen.rb', line 249

def dark_square_by_pgn square_pgn
  @@dark_squares.include?(@@pgn_number_hash[square_pgn])
end


    		
  





    
      

  

  
    #fen_array_from_plies(plies)  ⇒ Object 
  

  

  




  

    

get FEN array from plies



  





  



  

    
      


374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391

    		
    
      
# File 'lib/pgn2fen.rb', line 374

def fen_array_from_plies(plies)
  fen_array = []
  fen_array << @board_start_fen
  ply_number = 1 #ply_number starts at 1 for regular game
  unless @fen.nil?
    if @board_color_from_fen == "w"
      ply_number = (@fullmove.to_i * 2) + 1
    else
      ply_number = (@fullmove.to_i * 2)
    end
  end
  plies.each{|ply|
    #puts "ply=#{ply}, ply_number=#{ply_number}, move_number=#{ply_number/2 + 1}"
    fen_array << fen_for_ply(ply, ply_number)
    ply_number += 1
  }
  fen_array
end


    		
  





    
      

  

  
    #fen_castle_text  ⇒ Object 
  

  

  




  

    

get FEN castle text based on castling availability



  





  



  

    
      


458
459
460
461
462
463
464
465
466

    		
    
      
# File 'lib/pgn2fen.rb', line 458

def fen_castle_text
  text = ""
  if @can_white_castle_kingside; text.concat("K"); end
  if @can_white_castle_queenside; text.concat("Q"); end
  if @can_black_castle_kingside; text.concat("k"); end
  if @can_black_castle_queenside; text.concat("q"); end
  if text.empty?; text = "-"; end
  text
end


    		
  





    
      

  

  
    #fen_for_ply(ply, ply_number)  ⇒ Object 
  

  

  




  

    

get FEN from a ply and ply number



  





  



  

    
      


395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454

    		
    
      
# File 'lib/pgn2fen.rb', line 395

def fen_for_ply(ply, ply_number)
  #puts ply
  is_white = (ply_number % 2 != 0)
  @halfmove = @halfmove + 1
  long_ply = short_ply_to_long_ply(ply, is_white)

  if long_ply.eql? "O-O"
    if is_white
      make_ply_on_board("e1g1")
      make_ply_on_board("h1f1")
      @can_white_castle_kingside = false
      @can_white_castle_queenside = false
    else
      make_ply_on_board("e8g8")
      make_ply_on_board("h8f8")
      @can_black_castle_kingside = false
      @can_black_castle_queenside = false
    end
  elsif long_ply.eql? "O-O-O"
    if is_white
      make_ply_on_board("e1c1")
      make_ply_on_board("a1d1")
      @can_white_castle_kingside = false
      @can_white_castle_queenside = false
    else
      make_ply_on_board("e8c8")
      make_ply_on_board("a8d8")
      @can_black_castle_kingside = false
      @can_black_castle_queenside = false
    end
  else # rest of moves
    if is_white
      if @can_white_castle_kingside && long_ply[0,2] == "h1"; @can_white_castle_kingside = false; end
      if @can_white_castle_queenside && long_ply[0,2] == "a1"; @can_white_castle_queenside = false; end
    else
      if @can_black_castle_kingside && long_ply[0,2] == "h8"; @can_white_castle_kingside = false; end
      if @can_black_castle_queenside && long_ply[0,2] == "a8"; @can_white_castle_queenside = false; end
    end
    make_ply_on_board(long_ply)
  end

  fen = board_to_fen
  fen.concat(" ").concat(is_white ? "b": "w")
  fen.concat(" ").concat(fen_castle_text)
  #enpassent square
  unless @potential_enpassent_ply.nil?
    fen.concat(" ").concat(@potential_enpassent_ply)
    @potential_enpassent_ply = nil
  else
    fen.concat(" ").concat("-")
  end
  fen.concat(" ").concat(@halfmove.to_s)
  if is_white 
    fen.concat(" ").concat((@fullmove).to_s)
  else
    fen.concat(" ").concat((@fullmove += 1).to_s)
  end
  #pp_board
  fen
end


    		
  





    
      

  

  
    #file_for_hint(hint)  ⇒ Object 
  

  

  




  

    
      


222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243

    		
    
      
# File 'lib/pgn2fen.rb', line 222

def file_for_hint(hint)
  case hint
  when 'a'
    return @@aFile
  when 'b'
    return @@bFile
  when 'c'
    return @@cFile
  when 'd'
    return @@dFile
  when 'e'
    return @@eFile
  when 'f'
    return @@fFile
  when 'g'
    return @@gFile
  when 'h'
    return @@hFile
  else
    return nil
  end
end


    		
  





    
      

  

  
    #games_from_pgn(pgn)  ⇒ Object 
  

  

  




  

    
      


276
277
278
279
280
281
282
283
284
285
286
287
288

    		
    
      
# File 'lib/pgn2fen.rb', line 276

def games_from_pgn(pgn)
  games = []
  pos_array = pgn.enum_for(:scan, /\[Event/).map{Regexp.last_match.begin(0)}
    pos_array.each_with_index {|pos, index|
      if (pos_array.size > index + 1) # all elements but last
        single_game_pgn = pgn[pos..pos_array[index+1]-1]
      else # last element
        single_game_pgn = pgn[pos..-1]
      end
      games << game_from_pgn(single_game_pgn)
    }
    games
end


    		
  





    
      

  

  
    #init_board  ⇒ Object 
  

  

  




  

    
      


261
262
263
264
265
266
267
268
269
270
271
272
273
274

    		
    
      
# File 'lib/pgn2fen.rb', line 261

def init_board
  @board_start_fen.split(" ").first.each_char {|c|
    case c
    when 'r', 'n', 'b', 'q', 'k', 'p'
      @board << c
    when 'R', 'N', 'B', 'Q', 'K', 'P'
      @board << c
    when '1', '2', '3', '4', '5', '6', '7', '8'
      (0...c.to_i).each {|n| @board << "" }
    else
      # do nothing
    end
  }
end


    		
  





    
      

  

  
    #is_single_game  ⇒ Object 
  

  

  




  

    

check to verify PGN includes only a single game



  





  



  

    
      


292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311

    		
    
      
# File 'lib/pgn2fen.rb', line 292

def is_single_game
  count = @pgn_data.scan(/\[Event /).count
    #puts "Event count:#{count}"
    if count > 1; return false; end

    # result header also includes result, hence compare with 2
    count = @pgn_data.scan(/1-0/).count
    #puts "1-0 count:#{count}"
    if count > 2; return false; end

    count = @pgn_data.scan(/0-1/).count
    #puts "0-1 count:#{count}"
    if count > 2; return false; end

    count = @pgn_data.scan(/1\/2-1\/2/).count
    #puts "1/2-1/2 count:#{count}"
    if count > 2; return false; end

    true
end


    		
  





    
      

  

  
    #light_square_by_number(square_number)  ⇒ Object 
  

  

  




  

    
      


253
254
255

    		
    
      
# File 'lib/pgn2fen.rb', line 253

def light_square_by_number square_number
  @@light_squares.include?(square_number)
end


    		
  





    
      

  

  
    #light_square_by_pgn(square_pgn)  ⇒ Object 
  

  

  




  

    
      


245
246
247

    		
    
      
# File 'lib/pgn2fen.rb', line 245

def light_square_by_pgn square_pgn
  @@light_squares.include?(@@pgn_number_hash[square_pgn])
end


    		
  





    
      

  

  
    #make_ply_on_board(long_ply)  ⇒ Object 
  

  

  




  

    

make a ply on the board



  





  



  

    
      


492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510

    		
    
      
# File 'lib/pgn2fen.rb', line 492

def make_ply_on_board(long_ply)
  from_pgn = long_ply[0,2] 
  to_pgn = long_ply[2,2] 
  from_idx = @@pgn_number_hash[from_pgn]
  to_idx = @@pgn_number_hash[to_pgn]
  #puts "from_pgn:#{from_pgn}, to_pgn:#{to_pgn}, from_idx:#{from_idx}, to_idx:#{to_idx}"
  if @promotion
    if "P" == @board[from_idx] #white
      @board[to_idx] = @promotion_piece.upcase
    else #black
      @board[to_idx] = @promotion_piece.downcase
    end
    @promotion = false
    @promotion_piece = nil
  else #general case
    @board[to_idx] = @board[from_idx]
  end
  @board[from_idx] = ""
end


    		
  





    
      

  

  
    #parse_headers(headers)  ⇒ Object 
  

  

  




  

    
      


119
120
121
122
123
124
125
126

    		
    
      
# File 'lib/pgn2fen.rb', line 119

def parse_headers(headers)
  #puts headers
  headers.each {|header|
    key = HEADER_KEY_REGEX.match(header)[1]
    value = HEADER_VALUE_REGEX.match(header)[1]
    instance_variable_set(:"@#{key.downcase.to_sym}", value)
  }
end


    		
  





    
      

  

  
    #parse_pgn  ⇒ Object 
  

  

  




  

    
      


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
168
169
170

    		
    
      
# File 'lib/pgn2fen.rb', line 128

def parse_pgn
  unless is_single_game
    raise Pgn2FenError, 'Only a single game PGN is supported right now.'
  end
  headers = []
  @pgn_data.strip!
  pgn_data_array = @pgn_data.split("\n")
  pgn_data_array.each {|line|
    if line.index("[") == 0
      headers << line
    else
      break
    end
  }
  parse_headers(headers)
  pgn_data_array = pgn_data_array[headers.size..-1]
  # get pgn
  @pgn = ""
  pgn_data_array.each {|line|
      @pgn = pgn.concat(line).concat(" ")
  }
  @pgn = clean_pgn(@pgn)

  #if fen does exist, use that as start board
  unless @fen.nil?
    tokens = @fen.split
    unless tokens.size == 6
      raise Pgn2FenError, "Invalid FEN header #{@fen}"
    end
    @board_start_fen = @fen
    @board_color_from_fen = tokens[1]
    @fullmove = tokens[5].to_i
    castle_options = tokens[3]
    update_castle_options_from_fen(castle_options)
  else
    reset_castle_options(true)
  end 

  init_board
  @plies = plies_from_pgn(@pgn)
  @fen_array = fen_array_from_plies(@plies)
  self # allow chaining
end


    		
  





    
      

  

  
    #plies_from_pgn(pgn)  ⇒ Object 
  

  

  




  

    

get plies from pgn



  





  



  

    
      


315
316
317
318
319
320
321
322
323
324
325
326
327

    		
    
      
# File 'lib/pgn2fen.rb', line 315

def plies_from_pgn(pgn)
  moves = pgn.split(/[0-9]+\./)
  moves.shift # remove first ""
  plies = []
  moves.each {|move|
    move.strip!
    move.gsub!(".", "")
    move.split(" ").each {|ply|
      plies << ply
    }
  }
  plies
end


    		
  





    
      

  

  
    #pp_board  ⇒ Object 
  

  

  




  

    
      


543
544
545
546
547
548
549
550
551
552
553

    		
    
      
# File 'lib/pgn2fen.rb', line 543

def pp_board
  str = ""
  @board.each_with_index { |sq, idx|
    if sq.empty?; sq = "*"; end
    if (idx % 8 == 0 && idx != 0); str << "\n"; end
    str << sq << " "
  }
  puts "= = = = = = = ="
  puts str
  puts "= = = = = = = =\n\n\n"
end


    		
  





    
      

  

  
    #rank_for_hint(hint)  ⇒ Object 
  

  

  




  

    
      


199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220

    		
    
      
# File 'lib/pgn2fen.rb', line 199

def rank_for_hint(hint)
  case hint
  when '1'
    return @@firstRank
  when '2'
    return @@secondRank
  when '3'
    return @@thirdRank
  when '4'
    return @@fourthRank
  when '5'
    return @@fifthRank
  when '6'
    return @@sixthRank
  when '7'
    return @@seventhRank
  when '8'
    return @@eighthRank
  else
    return nil
  end
end


    		
  





    
      

  

  
    #remove_text_between_tokens_inclusive(text, open_token, close_token)  ⇒ Object 
  

  

  




  

    
      


355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370

    		
    
      
# File 'lib/pgn2fen.rb', line 355

def remove_text_between_tokens_inclusive(text, open_token, close_token)
  open_token_count = 0
  new_text = ""
  text.split("").each {|c|
    if c == open_token
      open_token_count += 1
    elsif c == close_token
      open_token_count -= 1
    else
      if open_token_count == 0
        new_text << c
      end
    end
  }
  new_text
end


    		
  





    
      

  

  
    #reset_castle_options(option)  ⇒ Object 
  

  

  




  

    
      


111
112
113
114
115
116

    		
    
      
# File 'lib/pgn2fen.rb', line 111

def reset_castle_options(option)
  @can_white_castle_kingside = option
  @can_white_castle_queenside = option
  @can_black_castle_kingside = option
  @can_black_castle_queenside = option
end


    		
  





    
      

  

  
    #short_ply_to_long_ply(ply, is_white)  ⇒ Object 
  

  

  




  

    

convert short ply to long ply



  





  



  

    
      


557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636

    		
    
      
# File 'lib/pgn2fen.rb', line 557

def short_ply_to_long_ply(ply, is_white)
  from_idx = -1
  to_idx = -1
  from_pgn = ""
  to_pgn = ""
  hint = nil

  if ply.eql?("O-O"); return ply; end
  if ply.eql?("O-O-O"); return ply; end
  unless ply.index('+').nil?; ply.sub!("+", ""); end
  unless ply.index('x').nil?; ply.sub!("x", ""); @halfmove = 0; end
  unless ply.index('=').nil?
    @promotion = true
    @promotion_piece = ply[-1]
    ply = ply.chop.chop
  end

  if ply.length == 2 # pawn non-capture
    to_pgn = ply
    to_idx = @@pgn_number_hash[to_pgn]
    if is_white
      if !@board[to_idx+8].empty?
        from_idx = to_idx+8
      else
        from_idx = to_idx+16
#            if @board[to_idx-1].eql?"p" or @board[to_idx+1].eql?"p"
          @potential_enpassent_ply = @@number_pgn_hash[from_idx-8]
#            end
      end
    else  # isBlack
      if !@board[to_idx-8].empty?
        from_idx = to_idx-8
      else
        from_idx = to_idx-16
#            if @board[to_idx-1].eql?"P" or @board[to_idx+1].eql?"P"
          @potential_enpassent_ply = @@number_pgn_hash[from_idx+8]
#            end
      end
    end
    from_pgn = @@number_pgn_hash[from_idx]
    @halfmove = 0
    return from_pgn + to_pgn
  end

  if ('a'..'h').include?(ply[0]) && ply.length == 3 #pawn capture, non-enpassent
    to_pgn = ply[1..-1]
    to_idx = @@pgn_number_hash[to_pgn]
    if is_white
      if @board[to_idx+7].eql?("P") && file_for_hint(ply[0]).include?(to_idx+7)
        from_idx = to_idx+7
      elsif @board[to_idx+9].eql?("P")&& file_for_hint(ply[0]).include?(to_idx+9)
        from_idx = to_idx+9
      end
    else #is_black
      if @board[to_idx-7].eql?("p") && file_for_hint(ply[0]).include?(to_idx-7)
        from_idx = to_idx-7
      elsif @board[to_idx-9].eql?("p") && file_for_hint(ply[0]).include?(to_idx-9)
        from_idx = to_idx-9
      end
    end
    if from_idx == -1; raise Pgn2FenError, "Error parsing pawn capture at ply #{ply}"; end
    from_pgn = @@number_pgn_hash[from_idx]
    @halfmove = 0
    return from_pgn + to_pgn
  end

  if ply.length == 3; to_pgn = ply[1,2]; end
  if ply.length() == 4
    to_pgn = ply[2,2]
    hint = ply[1]
  end
  to_idx = @@pgn_number_hash[to_pgn]

  if ply[0].downcase.eql?('r'); return short_ply_to_long_ply_for_rook(to_idx, to_pgn, hint, is_white); end
  if ply[0].downcase.eql?('n'); return short_ply_to_long_ply_for_knight(to_idx, to_pgn, hint, is_white); end
  if ply[0].downcase.eql?('b'); return short_ply_to_long_ply_for_bishop(to_idx, to_pgn, hint, is_white); end
  if ply[0].downcase.eql?('q'); return short_ply_to_long_ply_for_queen(to_idx, to_pgn, hint, is_white); end
  if ply[0].downcase.eql?('k'); return short_ply_to_long_ply_for_king(to_idx, to_pgn, hint, is_white); end
  return from_pgn + to_pgn
end


    		
  





    
      

  

  
    #short_ply_to_long_ply_for_bishop(to_idx, to_pgn, hint, is_white)  ⇒ Object 
  

  

  




  

    
      


763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859

    		
    
      
# File 'lib/pgn2fen.rb', line 763

def short_ply_to_long_ply_for_bishop(to_idx, to_pgn, hint, is_white)
  from_idx = -1
  from_pgn = ""
  piece = is_white ? "B" : "b"
  is_light = light_square_by_number(to_idx) ? true : false
  if (!hint.nil?)
    if @@one_thru_eight.include?(hint)
      from_pgn = to_pgn[0,1] + h
    end
    if @@a_thru_h.include?(hint)
      from_pgn = h + to_pgn[1,1]
    end
    return from_pgn + to_pgn
  else
    # check nw direction
    nw = to_idx
    while(nw > -1) do
      nw = nw - 9
      if (nw < 0)
        break
      end
#          puts "nw=#{nw}"
      if light_square_by_number(nw) != is_light # square colors don't match - overflow
        break
      elsif @board[nw].eql?(piece)
        from_idx = nw
        from_pgn = @@number_pgn_hash[from_idx]
        return from_pgn + to_pgn
      elsif @board[nw].eql?("")
        next
      else
        break
      end
    end
    # check ne direction
    ne = to_idx
    while(ne > 0) do
      ne = ne - 7
      if (ne < 1)
        break
      end
#          puts "ne=#{ne}"
      if light_square_by_number(ne) != is_light # square colors don't match - overflow
        break
      elsif @board[ne].eql?(piece)
        from_idx = ne
        from_pgn = @@number_pgn_hash[from_idx]
        return from_pgn + to_pgn
      elsif @board[ne].eql?("")
        next
      else
        break
      end
    end
    # check sw direction
    sw = to_idx
    while(sw < 63) do
      sw = sw + 7
      if (sw > 62)
        break
      end
#          puts "sw=#{sw}"
      if light_square_by_number(sw) != is_light # square colors don't match - overflow
        break
      elsif @board[sw].eql?(piece)
        from_idx = sw
        from_pgn = @@number_pgn_hash[from_idx]
        return from_pgn + to_pgn
      elsif @board[sw].eql?("")
        next
      else
        break
      end
    end
    # check se direction
    se = to_idx
    while(se < 64) do
      se = se + 9
      if (se > 63)
        break
      end
#          puts "se=#{se}"
      if light_square_by_number(se) != is_light # square colors don't match - overflow
        break
      elsif @board[se].eql?(piece)
        from_idx = se
        from_pgn = @@number_pgn_hash[from_idx]
        return from_pgn + to_pgn
      elsif @board[se].eql?("")
        next
      else
        break
      end
    end
  end
  return from_pgn + to_pgn
end


    		
  





    
      

  

  
    #short_ply_to_long_ply_for_king(to_idx, to_pgn, hint, is_white)  ⇒ Object 
  

  

  




  

    
      


1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047

    		
    
      
# File 'lib/pgn2fen.rb', line 1037

def short_ply_to_long_ply_for_king(to_idx, to_pgn, hint, is_white)
  from_idx = -1
  from_pgn = ""
  if is_white
    @board.reverse.each_with_index {|i,idx| if i.eql?("K"); from_idx = 63 - idx; break; end }
  else
   @board.each_with_index {|i,idx| if i.eql?("k"); from_idx = idx; break; end }
  end
  from_pgn = @@number_pgn_hash[from_idx]
  return from_pgn + to_pgn
end


    		
  





    
      

  

  
    #short_ply_to_long_ply_for_knight(to_idx, to_pgn, hint, is_white)  ⇒ Object 
  

  

  




  

    

  





  

Raises:





  

    
      


722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761

    		
    
      
# File 'lib/pgn2fen.rb', line 722

def short_ply_to_long_ply_for_knight(to_idx, to_pgn, hint, is_white)
  from_idx = -1
  from_pgn = ""
  piece = is_white ? "N" : "n"
  if !hint.nil?
    # -17,-15, 10, -6, 6, 10, 15, 17 are possible knight moves
    knight_moves = [17+to_idx, 17+to_idx, -15+to_idx, 15+to_idx, -10+to_idx, 10+to_idx, -6+to_idx, 6+to_idx]
    if @@one_thru_eight.include?(hint) 
      rank = rank_for_hint(hint)
      knight_moves = knight_moves & rank.to_a # intersection
    end
    if @@a_thru_h.include?(hint) 
      file = file_for_hint(hint)
      knight_moves = knight_moves & file.to_a #intersection
    end
    knight_moves.each {|idx|
      if @board[idx].eql?(piece)
        from_idx = idx
        from_pgn = @@number_pgn_hash[from_idx]
        return from_pgn + to_pgn
      end
    }
  else
    # -17,-15, 10, -6, 6, 10, 15, 17 are possible knight moves
    knight_moves = [-17, 17, -15, 15, -10, 10, -6, 6]
    knight_moves.each {|i|
      idx = to_idx + i
      if (idx < 0 && idx > 63)
        next
      end
      if @board[idx].eql?(piece)
        from_idx = idx
        from_pgn = @@number_pgn_hash[from_idx]
        return from_pgn + to_pgn
      end
    }
  end
  #return from_pgn + to_pgn
  raise Pgn2FenError, "Error parsing knight move to square #{to_pgn}"
end


    		
  





    
      

  

  
    #short_ply_to_long_ply_for_queen(to_idx, to_pgn, hint, is_white)  ⇒ Object 
  

  

  




  

    
      


861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035

    		
    
      
# File 'lib/pgn2fen.rb', line 861

def short_ply_to_long_ply_for_queen(to_idx, to_pgn, hint, is_white)
  # check bishop type moves
  from_idx = -1
  from_pgn = ""
  piece = is_white ? "Q" : "q"
  is_light = light_square_by_number(to_idx) ? true : false
  if (!hint.nil?)
    if @@one_thru_eight.include?(hint)
      from_pgn = to_pgn[0,1] + hint
    end
    if @@a_thru_h.include?(hint)
      from_pgn = hint + to_pgn[1,1]
    end
    return from_pgn + to_pgn
  else
    # check nw direction
    nw = to_idx
    while(nw > -1) do
      nw = nw - 9
      if (nw < 0)
        break
      end
      if light_square_by_number(nw) != is_light # square colors don't match - overflow
        break
      elsif @board[nw].eql?(piece)
        from_idx = nw
        from_pgn = @@number_pgn_hash[from_idx]
        return from_pgn + to_pgn
      elsif @board[nw].eql?("")
        next
      else
        break
      end
    end
    # check ne direction
    ne = to_idx
    while(ne > 0) do
      ne = ne - 7
      if (ne < 1)
        break
      end
      if light_square_by_number(ne) != is_light # square colors don't match - overflow
        break
      elsif @board[ne].eql?(piece)
        from_idx = ne
        from_pgn = @@number_pgn_hash[from_idx]
        return from_pgn + to_pgn
      elsif @board[ne].eql?("")
        next
      else
        break
      end
    end
    # check sw direction
    sw = to_idx
    while(sw < 63) do
      sw = sw + 7
      if (sw > 62)
        break
      end
      if light_square_by_number(sw) != is_light # square colors don't match - overflow
        break
      elsif @board[sw].eql?(piece)
        from_idx = sw
        from_pgn = @@number_pgn_hash[from_idx]
        return from_pgn + to_pgn
      elsif @board[sw].eql?("")
        next
      else
        break
      end
    end
    # check se direction
    se = to_idx
    while(se < 64) do
      se = se + 9
      if (se > 63)
        break
      end
      if light_square_by_number(se) != is_light # square colors don't match - overflow
        break
      elsif @board[se].eql?(piece)
        from_idx = se
        from_pgn = @@number_pgn_hash[from_idx]
        return from_pgn + to_pgn
      elsif @board[se].eql?("")
        next
      else
        break
      end
    end
  end
  if (from_pgn.length == 2)
    return from_pgn + to_pgn
  end
  # check rook type moves
  if !hint.nil?
    if @@one_thru_eight.include?(hint)
      from_pgn = to_pgn[0,1] + hint
    end
    if @@a_thru_h.include?(hint)
      from_pgn = hint + to_pgn[1,1]
    end
    return from_pgn + to_pgn
  else # no hint
    # check file
    up = to_idx
    while up > -1 do
      up = up - 8
      if (up < 0)
        break
      end
      if @board[up].eql?(piece)
        from_idx = up
        from_pgn = @@number_pgn_hash[from_idx]
        return from_pgn + to_pgn
      elsif @board[up].eql?("")
        next
      else
        break
      end
    end
    down = to_idx
    while down < 64 do
      down = down + 8
      if down > 63
        break
      end
      if @board[down].eql?(piece)
        from_idx = down
        from_pgn = @@number_pgn_hash[from_idx]
        return from_pgn + to_pgn
      elsif @board[down].eql?("")
        next
      else
        break
      end
    end

    # check rank
    left = to_idx
    while left > -1 do
      left = left  - 1
      if left % 8 == 7
        break
      end
      if @board[left].eql?(piece)
        from_idx = left
        from_pgn = @@number_pgn_hash[from_idx]
        return from_pgn + to_pgn
      elsif @board[left].eql?("")
        next
      else
        break
      end
    end
    right = to_idx
    while right < 64 do
      right = right + 1
      if right % 8 == 0
        break
      end
      if @board[right].eql?(piece)
        from_idx = right
        from_pgn = @@number_pgn_hash[from_idx]
        return from_pgn + to_pgn
      elsif @board[right].eql?("")
        next
      else 
        break
      end
    end
  end
  from_pgn + to_pgn
end


    		
  





    
      

  

  
    #short_ply_to_long_ply_for_rook(to_idx, to_pgn, hint, is_white)  ⇒ Object 
  

  

  




  

    
      


638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720

    		
    
      
# File 'lib/pgn2fen.rb', line 638

def short_ply_to_long_ply_for_rook(to_idx, to_pgn, hint, is_white)
  from_idx = -1
  from_pgn = ""
  piece = is_white ? "R" : "r"
  if !hint.nil?
    if @@one_thru_eight.include?(hint)
      from_pgn = to_pgn[0,1] + hint
    end
    if @@a_thru_h.include?(hint)
      from_pgn = hint + to_pgn[1,1]
    end
    return from_pgn + to_pgn
  else # no hint
    # check file
    up = to_idx
    while up > -1 do
      up = up - 8
      if (up < 0)
        break
      end
      if @board[up].eql?(piece)
        from_idx = up
        from_pgn = @@number_pgn_hash[from_idx]
        return from_pgn + to_pgn
      elsif @board[up].eql?("")
        next
      else
        break
      end
    end
    down = to_idx
    while down < 64 do
      down = down + 8
      if down > 63
        break
      end
      if @board[down].eql?(piece)
        from_idx = down
        from_pgn = @@number_pgn_hash[from_idx]
        return from_pgn + to_pgn
      elsif @board[down].eql?("")
        next
      else
        break
      end
    end

    # check rank
    left = to_idx
    while left > -1 do
      left = left  - 1
      if left % 8 == 7
        break
      end
      if @board[left].eql?(piece)
        from_idx = left
        from_pgn = @@number_pgn_hash[from_idx]
        return from_pgn + to_pgn
      elsif @board[left].eql?("")
        next
      else
        break
      end
    end
    right = to_idx
    while right < 64 do
      right = right + 1
      if right % 8 == 0
        break
      end
      if @board[right].eql?(piece)
        from_idx = right
        from_pgn = @@number_pgn_hash[from_idx]
        return from_pgn + to_pgn
      elsif @board[right].eql?("")
        next
      else
        break
      end
    end
  end
  from_pgn + to_pgn
end


    		
  





    
      

  

  
    #to_s  ⇒ Object 
  

  

  




  

    
      


172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197

    		
    
      
# File 'lib/pgn2fen.rb', line 172

def to_s
  str = ""
  str << "Event: #{@event}\n"
  str << "Site: #{@site}\n"
  str << "Date: #{@date}\n"
  str << "EventDate: #{@eventdate}\n"
  str << "Round: #{@round}\n"
  str << "White: #{@white}\n"
  str << "Black: #{@black}\n"
  str << "WhiteElo: #{@whiteElo}\n"
  str << "BlackElo: #{@blackElo}\n"
  str << "Result: #{@result}\n"
  str << "Eco: #{@eco}\n"
  str << "Plycount: #{@plycount}\n"
  str << "FEN: #{@fen}\n"

  str << "PGN: #{@pgn}\n"
  str << "Plies: #{@plies}\n"
  str << "FEN Array:\n"
  unless @fen_array.nil?
    @fen_array.each {|fen|
      str << fen << "\n"
    }
  end
  str
end


    		
  





    
      

  

  
    #update_castle_options_from_fen(castle_options)  ⇒ Object 
  

  

  




  

    

update castling options from FEN header



  





  



  

    
      


470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488

    		
    
      
# File 'lib/pgn2fen.rb', line 470

def update_castle_options_from_fen castle_options
  reset_castle_options(false)
  if castle_options == "-"
    return
  end
  tokens = castle_options.split("")
  tokens.each {|token|
    case token
    when "K" 
      @can_white_castle_kingside = true
    when "Q"
      @can_white_castle_queenside = true
    when "k"
      @can_black_castle_kingside = true
    when "q"
      @can_black_castle_queenside = true
    end
  }
end