NAME

Chess::Play - Play chess games, calculate legal moves, use a search algorithm

SYNOPSIS

  use Chess::Play;

  my $cp = Chess::Play->new();
  $cp->reset();
  $cp->import_fen($fen)
  $cp->export_fen()
  $cp->set_piece_val($p_val, $n_val, $b_val, $r_val, $q_val);
  $cp->set_depth($depth)
  $cp->legal_moves()
  $cp->do_move($move)
  $cp->best_move()
  $cp->game_over();
  $cp->print_board();
  $cp->play()
  $cp->xboard_play([$custom_name])

DESCRIPTION

This module allows to play a chess game using STDIN or the xboard graphical interface. Il also can calculate legal moves and uses the Alpha-Beta search algorithm to find the best move.

METHODS

* $cp = Chess::Play->new(): Create a new object to play chess.
* $cp->reset(): Reset to the start position.
* $cp->import_fen($fen): Set the position according to the FEN string $fen
* $fen = $cp->export_fen(): Export the current position to the FEN string $fen
* $cp->set_piece_val($p_val, $n_val, $b_val, $r_val, $q_val): Change default values for pieces (the defaults are : 1, 3, 3, 5, 9)
* $cp->set_depth($depth): Set the depth of the search algorithm (Alpha-Beta search).
* @legal_moves = $cp->legal_moves(): Calculate the list of legal moves
* $move_ok = $cp->do_move($move): execute a move (for instance "e2e4" or "a7a8q"). Return 1 if the move is legal, -1 if invalid, -2 if illegal
* $game_over = $cp->game_over(): Tell if the game is over (Sheckmate, Stalemate, Insufficient Material, 50 moves rule). Threeway repetition is not supported in this version. Return "" if the game is not over.
* $best_move = $cp->best_move(): Return the best move according to the search algorithm
* $cp->print_board();: Print an ASCII representation of the board
* $cp->play(): Play a chess game using STDIN
* $cp->xboard_play()
* $cp->xboard_play($custom_name): Play a chess game using xboard (only the basic xboad directives are supported). You can choose a name for your engine.

EXAMPLES

* Create a new Chess::Play object my $cp = Chess::Play->new();

* Execute some moves if ($cp->do_move("e2e4") == 1) {..} if ($cp->do_move("e7e5") == 1) {..}

* Calculate legal moves @legal_moves = $cp->legal_moves()

* Play a chess game using stdin (using coordinate notation) $cp->reset(); $ce->set_depth(2); $ce->play();

* Create an xboard-compatible chess engine $cp->reset(); $ce->set_depth(2); $cp->xboard_play("My_Chess_Engine")

* Use xboard xboard -fcp /path/to/my_engine.pl or xboard -fcp /path/to/my_engine.pl -scp /path/to/my_engine2.pl

* Find a mate in 2 $cp->import_fen("1R6/8/KN6/8/1k6/7r/2QP4/8 w - - 0 1"); $cp->set_depth(3); $bm = $cp->best_move();

AUTHOR

Giuliano Ippoliti, g1ul14n0 AT gmail