NAME

Chess::Opening::Book::Polyglot - Read polyglot opening books

SYNOPSIS

    $book = Chess::Opening::Book::Polyglot->new('opening.bin');
	$entry = $book->lookupFEN($fen) or die "position not found";
    

DESCRIPTION

The polyglot openning book format is a popular, open format for chess opening libraries. Chess::Opening::Book::Polyglot can be used for reading these opening books.

A polyglot opening book consists of a list of chess positions, each with a weighted list of possible continuation moves. The "weight" is a measure for the likelihood of a win after that particular move has been made.

There is no arbitrary limit on the size of an opening book that you can read with Chess::Opening::Book::Polyglot as the book is not read as a whole but the positions are searched inside the file and only the relevant part is loaded into memory. This is implemented in a fairly efficient manner. However, if you want to use the module for a chess engine (which you should'nt write in an interpreted language like Perl), you probably want to optimize the lookup a bit.

METHODS

new FILENAME

The constructor takes one single argument, the FILENAME of the opening book on disk. An exception is thrown if the file cannot be opened.

lookupFEN FEN

See "lookupFEN" in Chess::Opening::Book!

COPYRIGHT

Copyright (C) 2019 Guido Flohr <guido.flohr@cantanea.com>, all rights reserved.

SEE ALSO

Chess::Opening::Book, Chess::Opening::Book::Entry, Chess::Opening::Book::Move, perl(1)