NAME

Games::AlphaBeta::Reversi - Reversi position class for use with Games::AlphaBeta

SYNOPSIS

    package My::Reversi;
    use base qw(Games::AlphaBeta::Reversi);

    # implement drawing routine
    sub draw { ... }

    package main;
    use My::Reversi;
    use Games::AlphaBeta;

    my ($p, $g);
    $p = My::Reversi->new;
    $g = Games::AlphaBeta->new($p);

    while ($p = $g->abmove) {
        $p->draw;
    }

DESCRIPTION

This module implements a position-object suitable for use with Games::AlphaBeta. It inherits from the Games::AlphaBeta::Position base class, so be sure to read its documentation. The methods implemented there will not be described here.

METHODS

init()

Initialize the initial state. Call SUPER::init(@_) to do part of the work.

as_string

Return a plain-text representation of the current game position as a string.

findmoves [$own_call]

Return an array of all legal moves at the current position for the current player.

If $own_call is true, we have been recursively called by ourself to find out if the other player could move. If neither player can move, return undef to denote this as an ending position. Otherwise return a pass move.

evaluate

Evaluate a game position and return its fitness value.

apply $move

Apply a move to the current position, transforming it into the next position. Return reference to itself on succes, undef on error.

BUGS

The findmoves() method is too slow. This method is critical to performance when running under Games::AlphaBeta, as more than 60% of the execution time is spent there (when searching to ply 3). Both the evaluate() and endpos() routines use findmoves() internally, so by speeding this routine up we could gain a lot of speed.

SEE ALSO

The author's website, describing this and other projects: http://brautaset.org/projects/

AUTHOR

Stig Brautaset, <stig@brautaset.org>

COPYRIGHT AND LICENCE

Copyright (C) 2004 by Stig Brautaset

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.3 or, at your option, any later version of Perl 5 you may have available.