File Coverage

blib/lib/Bit/Compare.pm

Criterion	Covered	Total	%
statement	29	29	100.0
branch	10	12	83.3
condition	1	3	33.3
subroutine	5	5	100.0
pod	2	2	100.0
total	47	51	92.1

use strict;
use warnings;
package Bit::Compare;
{
  $Bit::Compare::VERSION = '0.001';
}
#ABSTRACT: Compare two "bit strings", returning differing bits

use Sub::Exporter -setup => {
    exports => [ qw/bitcompare bit/ ],
    groups => {
        default => [ qw/bitcompare/ ],
    },
};


sub bitcompare {
    if (@_ == 3) {
        shift; # remove class/package to support old calling forms
    }
    my ($s1, $s2) = @_;
    $s1 = bit($s1);
    $s2 = bit($s2);
    return unless ($s1 and $s2);
    my $v = "" . join("", unpack("c*", $s1 ^ $s2));
    $v =~ s/0//g;

    return length($v);
}


sub bit {
    my ($s) = @_;
    return unless defined $s;
    my @a;
    foreach (split(/(.{2})/, $s)) {
        next unless length("$_") > 0;
        my $v = hex($_);
        my $b = unpack("B*", pack("C",$v));
        if (length("$_") == 1) {
            $b = substr($b, -4);
        }
        push(@a, split(//, $b));
    }
    return (wantarray ? @a : join("", @a));
}

1;

__END__