NAME
    Encode::JIS2K - JIS X 0212 (aka JIS 2000) Encodings

SYNOPSIS
      use Encode::JIS2K;
      use Encode qw/encode decode/;
      $euc_2k = encode("euc-jisx0213", $utf8);
      $utf8   = decode("euc-jisx0213", $euc_jp);

ABSTRACT
    This module implements encodings that covers JIS X 0213 charset (AKA JIS
    2000, hence the module name). Encodings supported are as follows.

      Canonical     Alias                                      Description
      --------------------------------------------------------------------
      euc-jisx0213  qr/\beuc.*jp[ \-]?(?:2000|2k)$/i          EUC-JISX0213
                    qr/\bjp.*euc[ \-]?(2000|2k)$/i
                    qr/\bujis[ \-]?(?:2000|2k)$/i
      shiftjisx0213 qr/\bshift.*jis(?:2000|2k)$/i           Shift_JISX0213
                    qr/\bsjisp \-]?(?:2000|2k)$/i

      iso-2022-jp-3
      jis0213-1-raw                         JIS X 0213 plane 1, raw format
      jis0213-2-raw                         JIS X 0213 plane 2, raw format
      --------------------------------------------------------------------

DESCRIPTION
    To find out how to use this module in detail, see Encode.

what is JIS X 0213 anyway?
    Simply put, JIS X 0213 is a rework and reorganization of JIS X 0208 and
    JIS X 0212. They consist of two 94x94 planes which roughly corrensponds
    as follows;

      JIS X 0213 Plane 1 = JIS X 0208 + extension
      JIS X 0213 Plane 2 = JIS X 0212 reorganized + extension

    And here is the character repertoire there of at a glance.

              # of codepoints     Kuten Ku (rows) used
      --------------------------------------------------------
      JIS X 0208         6,879    1..8,16..83
      JIS X 0213-1       8,762    1..94 (all!)
      JIS X 0212         6,067    2,6..7,9..11,16..77
      JIS X 0213-2       2,436    1,3..5,8,12..15,78..94
      -------------------------------------------------------
      (JIS X0213 Total) 11,197

    JIS X 0213 was designed to extend JIS X 0208 and JIS X 0212 without
    being imcompatible to (classic) EUC-JP and Shift_JIS. The following
    characteristics are as a result thereof.

    * JIS X plane 1 is (almost) a superset of JIS X 0208. However, with
      Unicode 3.2.0 the mappings differ in 3 codepoints.

        Kuten   JIS X 0208 -> Unicode         JIS X 0213 -> Unicode
        --------------------------------------------------------------
        1-1-17  <UFFE3> # FULLWIDTH MACRON    <U203E> # OVERLINE
        1-1-29  <U2014> # EM DASH             <U2015> # HORIZONTAL BAR
        1-1-79  <UFFE5> # FULLWIDTH YEN SIGN  <U00A5> # YEN SIGN

    * By the same token, JIS X 0213 plane 2 contains JIS Dai-4 Suijun Kanji
      (JIS Kanji Repertoire Level 4). This allows EUC-JP's G3 to contain
      both JIS X 0212 and JIS 0213 plane 2.

      However, JIS X 0212:1990 already contains many of Dai-4 Suijun Kanji
      so EUC's G3 is subject to containing duplicate mappings.

    * Because of Halfwidth Katakana, Shift_JIS mapping has been tricky and
      it is even trickier. Here is a regex that matches Shift_JISX0213
      sequence (note: you have to "use bytes" to make it work!)

        $re_valid_shifjisx0213 =
          qr/^(?:
               [\x00-\x7f] |                            # ASCII or
               [\xa1-\xdf] |                            # JIS X 0201 KANA or
               [\x81-\x9f\xe0-\xfc][\x40-\x7e\x80-\xfc] # JIS X 0213
               )+$/xo;

  Note on EUC-JISX0213 (vs. EUC-JP)
    As of Encode-1.64, 'euc-jp' does support euc-jisx0213 for decoding.
    However, 'euc-jp' in Encode and 'euc-jisx0213' differ as follows;

                        euc-jp                   euc-jisx0213
      --------------------------------------------------------------
      Decodes....       (0201-K|0208|0212|0213)  ditto
      Round-Trip  (|0)  (020-K|0208|0212)        JIS X (0201-K|0213)
      Decode Only (|3)  those only found in 0213
                                            those only found in 0212
      --------------------------------------------------------------

AUTHORS
    Dan Kogai, "<dankogai+cpan at gmail.com>"

COPYRIGHT
    Copyright 2002-2023 by Dan Kogai "<dankogai+cpan at gmail.com>".

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

    See <http://www.perl.com/perl/misc/Artistic.html>

SEE ALSO
    Encode, Encode::JP

    Japanese Graphic Character Set for Information Interchange -- Plane 1
    <http://www.itscj.ipsj.or.jp/ISO-IR/228.pdf>

    Japanese Graphic Character Set for Information Interchange -- Plane 2
    <http://www.itscj.ipsj.or.jp/ISO-IR/229.pdf>

