NAME
Convert::DUDE - Conversion between Unicode and DUDE
SYNOPSIS
use Convert::DUDE ':all';
# handles 'dq--' prefix
$domain  = to_dude($utf8);
$utf8    = from_dude($domain);
# don't care about 'dq--' prefix
# not exported by default	      
$dudestr = dude_encode($utf8);
$utf8    = dude_decode($dudestr);
DESCRIPTION
This module provides functions to convert between DUDE (Differential Unicode Domain Encoding) and Unicode encodings.
Quoted from http://www.i-d-n.net/draft/draft-ietf-idn-dude-02.txt
DUDE is a reversible transformation from a sequence of nonnegative
integer values to a sequence of letters, digits, and hyphens (LDH
characters).  DUDE provides a simple and efficient ASCII-Compatible
Encoding (ACE) of Unicode strings for use with Internationalized
Domain Names.
FUNCTIONS
Following two functions are exported to your package when you use Convert::DUDE.
- to_dude
 - 
$domain = to_dude($utf8);takes UTF8-encoded string, encodes it in DUDE and adds 'dq--' prefix in front.
 - from_dude
 - 
$utf8 = from_dude($domain);takes 'dq--' prefixed DUDE encoded string and decodes it to original UTF8 strings.
 
Following two functions can be exported to your package when you import them explicitly.
- dude_encode
 - 
$dude = dude_encode($utf8);takes UTF8-encoded string, encodes it in DUDE. Note that it doesn't care about 'dq--' prefix.
 - dude_decode
 - 
$utf8 = dude_decode($dude);takes DUDE encoded string and decodes it to original UTF8 strings. Note that it doesn't care about 'dq--' prefix.
 
Those functions above may throw exeptions in case of error. You may have to catch 'em with eval block.
CLASS METHODS
- prefix
 - 
$prefix = Convert::DUDE->prefix; Convert::DUDE->prefix('xx--');gets/sets DUDE prefix. 'dq--' for default.
 
EXAMPLES
Here's a sample code which does RACE-DUDE conversion.
  use Convert::RACE;
  use Convert::DUDE;
  use Unicode::String qw(utf16);
	       
  my $race = "bq--aewrcsy";
  eval {
      my $utf16 = from_race($race);
      my $dude = to_dude(utf16($utf16)->utf8);
      print "RACE: $race => DUDE: $dude\n";
  };
  if ($@) {
      warn "Conversion failed: $@";
  }
  
CAVEATS
There's no constraints on the input. See internet draft for nameprep about IDN input validation.
TODO
Consider mixed-case annotation. See internet draft for DUDE for details.
AUTHOR
Tatsuhiko Miyagawa <miyagawa@bulknews.net>
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
This module comes without warranty of any kind.
SEE ALSO
Convert::RACE, http://www.i-d-n.net/, http://www.i-d-n.net/draft/draft-ietf-idn-dude-02.txt, Unicode::String, Jcode