/ 
Convert-DUDE-0.01
River stage zero No dependents
/ Convert::DUDE

NAME

Convert::DUDE - Conversion between Unicode and DUDE

SYNOPSIS

use Convert::DUDE ':all';

# handles 'dq--' prefix
$domain  = to_dude($utf16);
$utf16   = from_dude($domain);

# don't care about 'dq--' prefix
# not exported by default	      
$dudestr = dude_encode($utf16);
$utf16   = dude_decode($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
$domain = to_dude($utf16str);

takes UTF16-encoded string, encodes it in DUDE and adds 'dq--' prefix in front.

from_dude
$utf16str = from_dude($domain);

takes 'dq--' prefixed DUDE encoded string and decodes it to original UTF16 strings.

Following two functions can be exported to your package when you import them explicitly.

dude_encode
$dude = dude_encode($utf16str);

takes UTF16-encoded string, encodes it in DUDE. Note that it doesn't care about 'dq--' prefix.

dude_decode
$utf16str = dude_decode($dude);

takes DUDE encoded string and decodes it to original UTF16 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;

my $race = "bq--aewrcsy";

eval {
    my $utf16 = from_race($race);
    my $dude = to_dude($utf16);
    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.

  • to_dude() assumes inputs are UTF-16 strings. Thus, this module hasn't been tested against unassigned code points like "u+2C7EF u+2C7EF" in the DUDE intrernet draft. (Do I have to use Unicode::String?)

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