NAME

LBS::2D::Sparse - a 2D storage, using sparse hash

SYNOPSIS

    my $storage = Language::Befunge::Storage::2D::Sparse->new;
    $storage->clear;
    $storage->store(<<EOF);
    12345
    67890
    EOF

DESCRIPTION

This class implements a storage as defined in LBS. It makes the assumption that we're in a 2D Funge space for efficiency reasons. Therefore, it's only suited for befunge programs.

This storage is sparse, using a private hash with keys such as "$x,$y". Any value of a non-existing key defaults to 32 (space), as defined by funge specs.

PUBLIC METHODS

Constructor

my $storage = LBS::2D::Sparse->new;

Create a new LBS object.

Storage update

$storage->clear;

Clear the storage.

my $size = $storage->store_binary( $code [, $position] );

Store the given $code at the specified $position (defaulting to the origin coordinates).

Return the size of the code inserted, as a vector.

The code is a string, representing a block of Funge code. This is binary insertion, that is, EOL sequences are stored in Funge-space instead of causing the dimension counters to be resetted and incremented.

my $size = $storage->store( $code [, $position] );

Store the given $code at the specified $position (defaulting to the origin coordinates).

Return the size of the code inserted, as a vector.

The code is a string, representing a block of Funge code. Rows are separated by newlines.

$storage->set_value( $offset, $value );

Write the supplied $value in the storage at the specified $offset.

/!\ As in Befunge, code and data share the same playfield, the number stored can be either an instruction or raw data (or even both... Eh, that's Befunge! :o) ).

Data retrieval

my $dims = $storage->get_dims;

Return the dimensionality of the storage. For this module, the value is always 2.

my $vmin = $storage->min;

Return a LBV pointing to the lower bounds of the storage.

my $vmax = $storage->max;

Return a LBV pointing to the upper bounds of the storage.

my $val = $storage->get_value( $offset );

Return the number stored in the torus at the specified $offset. If the value hasn't yet been set, it defaults to the ordinal value of a space (ie, #32).

/!\ As in Befunge, code and data share the same playfield, the number returned can be either an instruction or raw data (or even both... Eh, that's Befunge! :o) ).

my $chr = $storage->get_char( $offset )

Return the character stored in the torus at the specified $offset. If the value is not between 0 and 255 (inclusive), get_char will return a string that looks like <np-0x4500>.

/!\ As in Befunge, code and data share the same playfield, the character returned can be either an instruction or raw data. No guarantee is made that the return value is printable.

my $str = $storage->rectangle( $pos, $size );

Return a string containing the data/code in the rectangle defined by the supplied vectors.

Miscellaneous methods

my $href = $storage->labels_lookup;

Parse the storage to find sequences such as ;:(\w[^\s;])[^;]*; and return a hash reference whose keys are the labels and the values an anonymous array with four values: a vector describing the absolute position of the character just after the trailing ;, and a vector describing the velocity that leads to this label.

This method will only look in the four cardinal directions, and does wrap basically like befunge93 (however, this should not be a problem since we're only using cardinal directions)

This allow to define some labels in the source code, to be used by Inline::Befunge (and maybe some exstensions).

SEE ALSO

Language::Befunge.

AUTHOR

Jerome Quelin, <jquelin@cpan.org>

COPYRIGHT & LICENSE

Copyright (c) 2001-2009 Jerome Quelin, all rights reserved.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.