package Algorithm::CheckDigits::M11_009;
use 5.006;
use strict;
use warnings;
use integer;
use version; our $VERSION = 'v1.3.2';
our @ISA = qw(Algorithm::CheckDigits);
my @weight = ( 2, 7, 6, 5, 4, 3, 2 );
my @keys = ('', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'Z', 'J' );
sub new {
my $proto = shift;
my $type = shift;
my $class = ref($proto) || $proto;
my $self = bless({}, $class);
$self->{type} = lc($type);
return $self;
} # new()
sub is_valid {
my ($self,$number) = @_;
if ($number =~ /^([fgst])?(\d{7})([a-jz])$/i) {
return (uc($3) eq $self->_compute_checkdigits($2));
}
return ''
} # is_valid()
sub complete {
my ($self,$number) = @_;
if($number =~ /^([fgst])?(\d{7})$/i) {
my $prefix = $1 || '';
return $prefix . $2 . $self->_compute_checkdigits($2);
}
return '';
} # complete()
sub basenumber {
my ($self,$number) = @_;
if( $number =~ /^([fgst])?(\d{7})([a-jz])$/i
and uc($3) eq $self->_compute_checkdigits($2)) {
my $prefix = $1 || '';
return $prefix . $2;
}
return '';
} # basenumber()
sub checkdigit {
my ($self,$number) = @_;
if ($number =~ /^([fgst])?(\d{7})([a-jz])$/i) {
return $self->_compute_checkdigits($2);
}
return undef;
} # checkdigit()
sub _compute_checkdigits {
my $self = shift;
my @digits = split(//,shift);
my $sum = 0;
for (my $i = 0; $i <= $#digits; $i++) {
$sum += $weight[$i] * $digits[$i];
}
$sum %= 11;
return $keys[11 - $sum];
} # _compute_checkdigit()
# Preloaded methods go here.
1;
__END__
=head1 NAME
CheckDigits::M11_009 - compute check digits NRIC (SG)
=head1 SYNOPSIS
use Algorithm::CheckDigits;
$nric = CheckDigits('nric_sg');
if ($nric->is_valid('S1234567D')) {
# do something
}
$cn = $nric->complete('S1234567');
# $cn = 'S1234567D'
$cd = $nric->checkdigit('S1234567D');
# $cd = 'D'
$bn = $nric->basenumber('S1234567D');
# $bn = 'S1234567';
=head1 DESCRIPTION
=head2 ALGORITHM
=over 4
=item 1
Beginning left every digit is weighted with 2, 7, 6, 5, 4, 3, 2
=item 2
The weighted digits are added.
=item 3
The sum from step 2 is taken modulo 11.
=item 4
The checkdigit is 11 minus the sum from step 3 converted to a
character according to the following table:
@cd = ('','A','B','C','D','E','F','G','H','I','Z','J', );
=back
=head2 METHODS
=over 4
=item is_valid($number)
Returns true only if C<$number> consists of seven digits
(optional preceded by a letter out of 'F', 'G', 'S', 'T')
followed by a valid letter according to the algorithm given above.
Returns false otherwise,
=item complete($number)
The check letter for C<$number> is computed and appended to the
end of C<$number>.
Returns the complete number with check digit or '' if C<$number>
does not consist solely of digits and letters.
=item basenumber($number)
Returns the basenumber of C<$number> if C<$number> has a valid check
digit.
Return '' otherwise.
=item checkdigit($number)
Returns '' if C<$number> is valid.
Return undef otherwise.
=back
=head2 EXPORT
None by default.
=head1 AUTHOR
Mathias Weidner, C<< <mamawe@cpan.org> >>
=head1 SEE ALSO
L<perl>,
L<CheckDigits>,
F<www.pruefziffernberechnung.de>,
=cut