=head1 NAME

Web::DomainName::Punycode - A wrapper for Punycode encoding and decoding

=head1 SYNOPSIS

  use Web::DomainName::Punycode;
  $out = encode_punycode $in;
  $out = decode_punycode $in;

=head1 DESCRIPTION

The C<Web::DomainName::Punycode> module provides functions to encode and
decode Punycode.

=head1 FUNCTIONS

This module exports two functions:

=over 4

=item $out = encode_punycode $in

Encode the given string.  It returns the Punycode-encoded
representation, i.e. a string of ASCII characters.  If the input
cannot be encoded, C<undef> is returned.

=item $out = decode_punycode $in

Decode the given string.  It returns the Punycode-decoded
representation, i.e. a string of Unicode characters.  If the input
cannot be decoded, e.g. because the input is not a Punycode-encoded
string, C<undef> is returned.

=back

=head1 SEE ALSO

RFC 3492, I<Punycode: A Bootstring encoding of Unicode for
Internationalized Domain Names in Applications (IDNA)>, March 2003.
<https://tools.ietf.org/html/rfc3492>.

SuikaWiki:Punycode <https://suika.suikawiki.org/~wakaba/wiki/sw/n/Punycode>.

Although there are a number of Punycode implementations written in
Perl, they are broken or badly designed (see "Implementation" section
of <https://suika.suikawiki.org/~wakaba/wiki/sw/n/Punycode>).  Relatively
better implementations of Punycode include:

L<Net::LibIDN>.  GNU IDN Library - Libidn <http://www.gnu.org/s/libidn/>.

L<URI::_punycode>.

Previous version of the L<Web::DomainName::Punycode> depend on one of
these modules.  However, for the ease of deployment, current version
of the module contains a copy of L<URI::_punycode> such that no XS or
Perl module is required for encoding and decoding.

=head1 AUTHOR

Wakaba <wakaba@suikawiki.org>.

=head1 ACKNOWLEDGEMENTS

This module contains a copy of L<URI::_punycode>, whose credit
contains:

  Tatsuhiko Miyagawa <miyagawa@bulknews.net> is the author of
  IDNA::Punycode v0.02 which was the basis for this module.

=head1 LICENSE

Copyright 2011-2012 Wakaba <wakaba@suikawiki.org>.

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

=cut