package GridFiller::Constants;
use strict;
use warnings;
use Scalar::Readonly qw(readonly_on);
use namespace::autoclean;
require Exporter;

our @ISA='Exporter';
our @EXPORT=();
our @EXPORT_OK=qw($HORIZONTAL $VERTICAL $BLACK $WHITE $NOTHING);
our %EXPORT_TAGS=(
    colours => [qw($BLACK $WHITE $NOTHING)],
    directions => [qw($HORIZONTAL $VERTICAL)],
    all => [@EXPORT_OK],
);

our $VERTICAL = 1;
our $HORIZONTAL = 2;

our $NOTHING = 0;
our $BLACK = 1;
our $WHITE = 2;

readonly_on($VERTICAL);
readonly_on($HORIZONTAL);
readonly_on($NOTHING);
readonly_on($BLACK);
readonly_on($WHITE);

1;