NAME

       Regexp::Common::support -- Support functions for Regexp::Common.

SYNOPSIS

           use Regexp::Common::_support qw /luhn/;

           luhn ($number)    # Returns true/false.

DESCRIPTION

       This module contains some subroutines to be used by other "Regexp::Common" modules. It's
       not intended to be used directly. Subroutines from the module may disappear without any
       notice, or their meaning or interface may change without notice.

       luhn
           This subroutine returns true if its argument passes the luhn checksum test.

SEE ALSO

       <http://www.webopedia.com/TERM/L/Luhn_formula.html>.

AUTHOR

       Abigail (regexp-common@abigail.be).

BUGS AND IRRITATIONS

       Bound to be plenty.

LICENSE and COPYRIGHT

       This software is Copyright (c) 2001 - 2017, Damian Conway and Abigail.

       This module is free software, and maybe used under any of the following licenses:

        1) The Perl Artistic License.     See the file COPYRIGHT.AL.
        2) The Perl Artistic License 2.0. See the file COPYRIGHT.AL2.
        3) The BSD License.               See the file COPYRIGHT.BSD.
        4) The MIT License.               See the file COPYRIGHT.MIT.