package Net::IDN::Punycode;

use 5.006;

use strict;
use utf8;
use warnings;

use Exporter;

our $VERSION = "1.101";
$VERSION = eval $VERSION;

our @ISA = qw(Exporter);
our @EXPORT = ();
our @EXPORT_OK = ();
our %EXPORT_TAGS = ( 'all'  => [ qw(encode_punycode decode_punycode) ], );
Exporter::export_ok_tags(keys %EXPORT_TAGS);
our $_NO_XS;

eval { 
  die if $_NO_XS;
  require XSLoader;
  XSLoader::load('Net::IDN::Punycode'); 
};

if (!defined(&encode_punycode)) {
  require Net::IDN::Punycode::PP;
  Net::IDN::Punycode::PP->import(qw(:all));
}

1;
__END__

=head1 NAME

Net::IDN::Punycode - A Bootstring encoding of Unicode for IDNA (S<RFC 3492>)

=head1 SYNOPSIS

  use Net::IDN::Punycode qw(:all);
  $punycode = encode_punycode($unicode);
  $unicode  = decode_punycode($punycode);

=head1 DESCRIPTION

This module implements the Punycode encoding, and only the Punycode encoding.

This module does not implement any other steps required for converting
internationalised domain names (IDNs) to and from ASCII. In particular, it does
not do any string preparation as specified by I<Nameprep>/I<IDNA2008>/I<PRECIS>
and does not add nor remove the ACE prefix (C<xn-->). Thus, use
L<Net::IDN::Encode> if you want to convert domain names.

Punycode is an instance of a more general algorithm called Bootstring, which
allows strings composed from a small set of "basic" code points to uniquely
represent any string of code points drawn from a larger set. Punycode is
Bootstring with particular parameter values appropriate for IDNA.

=head1 WARNING

You may be tempted to use this module directly and add/remove the ACE prefix
(C<xn-->) in your code for performance reasons. Usually, this is not a good
idea.  If you convert domain labels (or other strings) without proper
prepration, you may end up with an ASCII encoding that is not interoperable or
even poses security issues due to spoofing.

Even if you think that your domain names are valid and already mapped to the
correct form, this may not be true. For example, some environments might
automatically convert your perfectly valiad domain names to a different but
equivalent Unicode normalisation form (e.g., NFD instead of NFC), which already
breaks IDNA.

=head1 FUNCTIONS

No functions are exported by default. You can use the tag C<:all>
or import them individually.

The following functions are available:

=over

=item encode_punycode($input)

Encodes C<$input> with Punycode and returns the result.

This function will throw an exception on invalid/unencodable input.

=item decode_punycode($input)

Decodes C<$input> with Punycode and returns the result.

This function will throw an exception on invalid input.

=back

=head1 AUTHORS

Tatsuhiko Miyagawa E<lt>miyagawa@bulknews.netE<gt> (versions 0.01 to 0.02)

Claus FE<auml>rber E<lt>CFAERBER@cpan.orgE<gt> (versions 1.000 and higher)

=head1 LICENSE

Copyright 2002-2004 Tatsuhiko Miyagawa E<lt>miyagawa@bulknews.netE<gt>

Copyright 2007-2014 Claus FE<auml>rber E<lt>CFAERBER@cpan.orgE<gt>

This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself.

=head1 SEE ALSO

S<RFC 3492> (L<http://www.ietf.org/rfc/rfc3492.txt>),
L<IETF::ACE>, L<Convert::RACE>

=cut
