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lib/AI/Evolve/Befunge/Critter.pm  view on Meta::CPAN

package AI::Evolve::Befunge::Critter;
use strict;
use warnings;

use Language::Befunge;
use Language::Befunge::Storage::Generic::Vec;
use IO::File;
use Carp;
use Perl6::Export::Attrs;
use Scalar::Util qw(weaken);

use base 'Class::Accessor::Fast';
__PACKAGE__->mk_accessors(
    # basic values
    qw{ boardsize codesize code color dims maxlen maxsize minsize },
    # token currency stuff
    qw{ tokens codecost itercost stackcost repeatcost threadcost },
    # other objects we manage
    qw{ blueprint physics interp }
);

use AI::Evolve::Befunge::Util;
use aliased 'AI::Evolve::Befunge::Critter::Result' => 'Result';

=head1 NAME

    AI::Evolve::Befunge::Critter - critter execution environment


=head1 DESCRIPTION

This module is where the actual execution of Befunge code occurs.  It
contains everything necessary to set up and run the code in a safe
(sandboxed) Befunge universe.

This universe contains the Befunge code (obviously), as well as the
current board game state (if any).  The Befunge code exists in the
negative vector space (with the origin at 0, Befunge code is below
zero on all axes).  Board game info, if any, exists as a square (or
hypercube) which starts at the origin.

The layout of befunge code space looks like this (for a 2d universe):

       |----------|         |
       |1         |         |
       |09876543210123456789|
    ---+--------------------+---
    -10|CCCCCCCCCC          |-10
     -9|CCCCCCCCCC|         | -9
     -8|CCCCCCCCCC          | -8
     -7|CCCCCCCCCC|         | -7
     -6|CCCCCCCCCC          | -6
     -5|CCCCCCCCCC|         | -5
     -4|CCCCCCCCCC          | -4
     -3|CCCCCCCCCC|         | -3
     -2|CCCCCCCCCC          | -2
     -1|CCCCCCCCCC|         | -1
    --0| - - - - -BBBB - - -|0--
      1|          BBBB      |  1
      2|          BBBB      |  2
      3|          BBBB      |  3
      4|                    |  4
      5|          |         |  5
      6|                    |  6
      7|          |         |  7
      8|                    |  8
      9|          |         |  9
    ---+--------------------+---
       |09876543210123456789|
       |1         |         |
       |----------|         |

Where:

    C is befunge code.   This is the code under test.
    B is boardgame data. Each location is binary 0, 1 or 2 (or
                         whatever tokens the game uses to represent
                         unoccupied spaces, and the various player
                         pieces).  The B section only exists for
                         board game applications.

Everything else is free for local use.  Note that none of this is
write protected - a program is free to reorganize and/or overwrite
itself, the game board, results table, or anything else within the
space it was given.

The universe is implemented as a hypercube of 1 or more dimensions.
The universe size is simply the code size times two, or the board size
times two, whichever is larger.  If the board exists in 2 dimensions
but the code exists in more, the board will be represented as a square
starting at (0,0,...) and will only exist on plane 0 of the non-(X,Y)
axes.

Several attributes of the universe are pushed onto the initial stack,
in the hopes that the critter can use this information to its
advantage.  The values pushed are (in order from the top of the stack
(most accessible) to the bottom (least accessible)):

    * the Physics token (implying the rules of the game/universe)
    * the number of dimensions this universe operates in