/ 
Chess4p-0.0.4
/ Chess4p::Board

NAME

Board - Chess board class

SYNOPSIS

The below is just a small sample, and far from extensive.

For more elaborate examples, see the prototypes directory in the Git repo.

use Board;

my $board = Board->fromFen($fen);

print $board->ascii();

my $move = $board->parse_move_san('e4');

$board->push_move($move);

$board->pop_move();

DESCRIPTION

Board provides Board objects, with features including

  • Construction from FEN

  • FEN output

  • Generate legal moves

  • SAN input / output

  • Making moves to update the board, and going back again ('unmaking' the moves).

  • Mirror the board vertically.

    Other kinds of mirrors and rotation may be added in later versions.

  • Get other properties of the board position

METHODS

fromFen($fen)

Constructor. Create a Board from a FEN string (Forsyth–Edwards Notation). If the input $fen is empty, use the conventional start position.

empty()

Constructor. Create an empty Board.

copyOf($board)

Copy constructor. Create a Board as a copy of the input Board.

fen()

Get the FEN for this board position.

errors()

Return undef if position is valid. Otherwise, a string describing the error.

ascii()

Write the board as ASCII.

Get an iterator over the legal moves from this position.

Get legal moves from this position.

to_move()

Return the side to move.

parse_san($san)

Parse a SAN string with this board as the context. Return the legal move specified by the SAN string, if such a move can be uniquely determined. Croak if no such unique legal move can be determined.

push_move($move)

Update with the given *move* and push it to the move Moves are not checked for legality. It is the caller's responsibility to ensure that the move is at least pseudo-legal or a null move. Null moves just increment the move counters, switch turns and forfeit en passant capturing.

push_move_san($san)

Assuming the input is a valid move in SAN notation, will push the move. Croak if not a valid move. See push_move($move).

push_move_uci($uci)

Assuming the input is a valid move in UCI notation, will push the move. See push_move($move).

pop_move()

Restore previous position and return last move from stack. If move stack is empty, no-op and return undef.

piece_at($square)

Get the piece at given square.

remove_piece_at($square)

Remove the piece at given square. If square is empty, does nothing.

set_piece_at($square, $piece)

Put given piece/pawn on given square. Any existing piece/pawn on that square is removed.

kingside_castling_right($side)

Is kingside castling allowed for the given side?

$side = 'w' or 'b'

queenside_castling_right($side)

Is queenside castling allowed for the given side?

$side = 'w' or 'b'

ep_square()

En passant capture square, or undef if N/A

fullmove_number()

Counts move pairs. Starts at 1, increments after every Black move.

halfmove_clock()

Number of ply since last capture or pawn move.

apply_mirror()

Mirror this board vertically.

san($move)

Get the Standard Algebraic Notation of the given move in the context of this position.

ply()

Get number of half-moves since start of game.

AUTHOR

Ejner Borgbjerg

LICENSE

Perl Artistic License, GPL