The Perl and Raku Conference 2025: Greenville, South Carolina - June 27-29 Learn more

ABALAMA / Acrux-0.06 / lib / Acrux / Digest / M11R.pm 

            

              
1
2
3
—
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110

              
package Acrux::Digest::M11R;
use strict;
use utf8;
=encoding utf-8
=head1 NAME
Acrux::Digest::M11R - interface for modulus 11 (recursive) check digit calculation
=head1 SYNOPSIS
    use Acrux::Digest::M11R;
    my $m11r = Acrux::Digest::M11R->new();
    my $digest = $m11r->digest( "123456789" ); # 5
=head1 DESCRIPTION
This is Digest backend module that provides calculate the modulus 11 (recursive) check digit
=head1 METHODS
This class inherits all methods from L<Acrux::Digest> and implements the following new ones
=head2 digest
    my $digest = $m11r->digest( "123456789" ); # 5
Returns M11R checkdigit by specified digits-string
=head1 HISTORY
See C<Changes> file
=head1 TO DO
See C<TODO> file
=head1 SEE ALSO
L<Acrux::Digest>, L<Algorithm::CheckDigits::M11_015>, B<check_okpo()>
=head1 AUTHOR
Serż Minus (Sergey Lepenkov) L<https://www.serzik.com> E<lt>abalama@cpan.orgE<gt>
=head1 COPYRIGHT
Copyright (C) 1998-2024 D&D Corporation. All Rights Reserved
=head1 LICENSE
This program is free software; you can redistribute it and/or
modify it under the same terms as Perl itself.
See C<LICENSE> file and L<https://dev.perl.org/licenses/>
=cut
our $VERSION = '0.01';
use Carp;
use parent qw/Acrux::Digest/;
sub digest {
    # See also: Algorithm::CheckDigits::M11_015 and check_okpo()
    my $self = shift;
    my $data = shift;
       $self->data($data) if defined $data;
    my $test = $self->data;
    croak "Incorrect input digit-string" if !defined($test) || $test =~ m/[^0-9]/g;
    my $len = length($test);
    my $iters = ($len + (($len & 1) ? 1 : 0)) / 2;
    my @digits = split(//, $test); # Get all digits from input string of chars
    #printf "Test=%s; len=%d; iters=%d\n", $test, $len, $iters;
    my $w_lim = 10; # Maximum for round-robin(10) weight list: 1,2,3,4,5,6,7,8,9,10,1,2,3,4,5...
    my $step = 2; # Step for weight list offset calculation for next iteration
    # Calculation sum for one weight list by ofset
    my $calc = sub {
        my $off = shift || 0;
        my $s = 0;
        for (my $i = 0; $i < $len; $i++) {
            my $w = (($i + $off) % $w_lim) + 1;
            $s += ($w * $digits[$i]);
            #printf " > i=%d; d=%d; w=%d; sum=%d\n", $i, $digits[$i], $w, $s;
        }
        return $s % 11;
    };
    # Main cycle
    my $sum = 0;
    for (my $j = 0; $j < $iters; $j++) {
        my $offset = $j*$step;
        $sum = $calc->($offset);
        #printf " >> j=%d; offset=%d; sum=%d\n", $j, $offset, $sum;
        last if $sum < 10;
    }
    $sum = 0 if $sum >= 10; # 0 if incorrect again
    #printf " >>> sum=%d\n", $sum;
    return $sum;
}
1;
__END__