Unicode::Collate::Locale - Linguistic tailoring for DUCET via Unicode::Collate

- NAME
- SYNOPSIS
- DESCRIPTION
  - Constructor
  - Methods
  - A list of tailorable locales
  - A list of variant codes and their aliases
- INSTALL
- CAVEAT
  - Reference
- AUTHOR
- SEE ALSO

# NAME

Unicode::Collate::Locale - Linguistic tailoring for DUCET via Unicode::Collate

# SYNOPSIS

      use Unicode::Collate::Locale;

      #construct
      $Collator = Unicode::Collate::Locale->
          new(locale => $locale_name, %tailoring);

      #sort
      @sorted = $Collator->sort(@not_sorted);

      #compare
      $result = $Collator->cmp($a, $b); # returns 1, 0, or -1.

Note: Strings in `@not_sorted`, `$a` and `$b` are interpreted according to Perl's Unicode support. See perlunicode, perluniintro, perlunitut, perlunifaq, utf8. Otherwise you can use `preprocess` (cf. `Unicode::Collate`) or should decode them before.

# DESCRIPTION

This module provides linguistic tailoring for it taking advantage of `Unicode::Collate`.

## Constructor

The `new` method returns a collator object.

A parameter list for the constructor is a hash, which can include a special key `locale` and its value (case-insensitive) standing for a Unicode base language code (two or three-letter). For example, `Unicode::Collate::Locale->new(locale => 'ES')` returns a collator tailored for Spanish.

`$locale_name` may be suffixed with a Unicode script code (four-letter), a Unicode region (territory) code, a Unicode language variant code. These codes are case-insensitive, and separated with `'_'` or `'-'`. E.g. `en_US` for English in USA, `az_Cyrl` for Azerbaijani in the Cyrillic script, `es_ES_traditional` for Spanish in Spain (Traditional).

If `$locale_name` is not available, fallback is selected in the following order:

        1. language with a variant code
        2. language with a script code
        3. language with a region code
        4. language
        5. default

Tailoring tags provided by `Unicode::Collate` are allowed as long as they are not used for `locale` support. Esp. the `table` tag is always untailorable, since it is reserved for DUCET.

However `entry` is allowed, even if it is used for `locale` support, to add or override mappings.

E.g. a collator for Spanish, which ignores diacritics and case difference (i.e. level 1), with reversed case ordering and no normalization.

        Unicode::Collate::Locale->new(
            level => 1,
            locale => 'es',
            upper_before_lower => 1,
            normalization => undef
        )

Overriding a behavior already tailored by `locale` is disallowed if such a tailoring is passed to `new()`.

        Unicode::Collate::Locale->new(
            locale => 'da',
            upper_before_lower => 0, # causes error as reserved by 'da'
        )

However `change()` inherited from `Unicode::Collate` allows such a tailoring that is reserved by `locale`. Examples:

        new(locale => 'fr_ca')->change(backwards => undef)
        new(locale => 'da')->change(upper_before_lower => 0)
        new(locale => 'ja')->change(overrideCJK => undef)

## Methods

`Unicode::Collate::Locale` is a subclass of `Unicode::Collate` and methods other than `new` are inherited from `Unicode::Collate`.

Here is a list of additional methods:

`$Collator->getlocale`

  Returns a language code accepted and used actually on collation. If linguistic tailoring is not provided for a language code you passed (intensionally for some languages, or due to the incomplete implementation), this method returns a string `'default'` meaning no special tailoring.

`$Collator->locale_version`

  (Since Unicode::Collate::Locale 0.87) Returns the version number (perhaps `/\d\.\d\d/`) of the locale, as that of Locale/*.pl.

  Note: Locale/*.pl that a collator uses should be identified by a combination of return values from `getlocale` and `locale_version`.

## A list of tailorable locales

          locale name       description
        --------------------------------------------------------------
          af                Afrikaans
          ar                Arabic
          as                Assamese
          az                Azerbaijani (Azeri)
          be                Belarusian
          bn                Bengali
          bs                Bosnian (tailored as Croatian)
          bs_Cyrl           Bosnian in Cyrillic (tailored as Serbian)
          ca                Catalan
          cs                Czech
          cy                Welsh
          da                Danish
          de__phonebook     German (umlaut as 'ae', 'oe', 'ue')
          de_AT_phonebook   Austrian German (umlaut primary greater)
          dsb               Lower Sorbian
          ee                Ewe
          eo                Esperanto
          es                Spanish
          es__traditional   Spanish ('ch' and 'll' as a grapheme)
          et                Estonian
          fa                Persian
          fi                Finnish (v and w are primary equal)
          fi__phonebook     Finnish (v and w as separate characters)
          fil               Filipino
          fo                Faroese
          fr_CA             Canadian French
          gu                Gujarati
          ha                Hausa
          haw               Hawaiian
          he                Hebrew
          hi                Hindi
          hr                Croatian
          hu                Hungarian
          hy                Armenian
          ig                Igbo
          is                Icelandic
          ja                Japanese [1]
          kk                Kazakh
          kl                Kalaallisut
          kn                Kannada
          ko                Korean [2]
          kok               Konkani
          lkt               Lakota
          ln                Lingala
          lt                Lithuanian
          lv                Latvian
          mk                Macedonian
          ml                Malayalam
          mr                Marathi
          mt                Maltese
          nb                Norwegian Bokmal
          nn                Norwegian Nynorsk
          nso               Northern Sotho
          om                Oromo
          or                Oriya
          pa                Punjabi
          pl                Polish
          ro                Romanian
          sa                Sanskrit
          se                Northern Sami
          si                Sinhala
          si__dictionary    Sinhala (U+0DA5 = U+0DA2,0DCA,0DA4)
          sk                Slovak
          sl                Slovenian
          sq                Albanian
          sr                Serbian
          sr_Latn           Serbian in Latin (tailored as Croatian)
          sv                Swedish (v and w are primary equal)
          sv__reformed      Swedish (v and w as separate characters)
          ta                Tamil
          te                Telugu
          th                Thai
          tn                Tswana
          to                Tonga
          tr                Turkish
          ug_Cyrl           Uyghur in Cyrillic
          uk                Ukrainian
          ur                Urdu
          vi                Vietnamese
          vo                Volapu"k
          wae               Walser
          wo                Wolof
          yo                Yoruba
          zh                Chinese
          zh__big5han       Chinese (ideographs: big5 order)
          zh__gb2312han     Chinese (ideographs: GB-2312 order)
          zh__pinyin        Chinese (ideographs: pinyin order) [3]
          zh__stroke        Chinese (ideographs: stroke order) [3]
          zh__zhuyin        Chinese (ideographs: zhuyin order) [3]
        --------------------------------------------------------------

Locales according to the default UCA rules include am (Amharic) without `[reorder Ethi]`, bg (Bulgarian) without `[reorder Cyrl]`, chr (Cherokee) without `[reorder Cher]`, de (German), en (English), fr (French), ga (Irish), id (Indonesian), it (Italian), ka (Georgian) without `[reorder Geor]`, mn (Mongolian) without `[reorder Cyrl Mong]`, ms (Malay), nl (Dutch), pt (Portuguese), ru (Russian) without `[reorder Cyrl]`, sw (Swahili), zu (Zulu).

Note

[1] ja: Ideographs are sorted in JIS X 0208 order. Fullwidth and halfwidth forms are identical to their regular form. The difference between hiragana and katakana is at the 4th level, the comparison also requires `(variable => 'Non-ignorable')`, and then `katakana_before_hiragana` has no effect.

[2] ko: Plenty of ideographs are sorted by their reading. Such an ideograph is primary (level 1) equal to, and secondary (level 2) greater than, the corresponding hangul syllable.

[3] zh__pinyin, zh__stroke and zh__zhuyin: implemented alt='short', where a smaller number of ideographs are tailored.

## A list of variant codes and their aliases

          variant code       alias
        ------------------------------------------
          dictionary         dict
          phonebook          phone     phonebk
          reformed           reform
          traditional        trad
        ------------------------------------------
          big5han            big5
          gb2312han          gb2312
          pinyin
          stroke
          zhuyin
        ------------------------------------------

Note: 'pinyin' is Han in Latin, 'zhuyin' is Han in Bopomofo.

# INSTALL

Installation of `Unicode::Collate::Locale` requires Collate/Locale.pm, Collate/Locale/*.pm, Collate/CJK/*.pm and Collate/allkeys.txt. On building, `Unicode::Collate::Locale` doesn't require any of data/*.txt, gendata/*, and mklocale. Tests for `Unicode::Collate::Locale` are named t/loc_*.t.

# CAVEAT

Tailoring is not maximum

  Even if a certain letter is tailored, its equivalent would not always tailored as well as it. For example, even though W is tailored, fullwidth W (`U+FF37`), W with acute (`U+1E82`), etc. are not tailored. The result may depend on whether source strings are normalized or not, and whether decomposed or composed. Thus `(normalization => undef)` is less preferred.

Collation reordering is not supported

  The order of any groups including scripts is not changed.

## Reference

          locale            based CLDR or other reference
        --------------------------------------------------------------------
          af                30 = 1.8.1
          ar                30 = 28 ("compat" wo [reorder Arab]) = 1.9.0
          as                30 = 28 (without [reorder Beng..]) = 23
          az                30 = 24 ("standard" wo [reorder Latn Cyrl])
          be                30 = 28 (without [reorder Cyrl])
          bn                30 = 28 ("standard" wo [reorder Beng..]) = 2.0.1
          bs                30 = 28 (type="standard": [import hr])
          bs_Cyrl           30 = 28 (type="standard": [import sr])
          ca                30 = 23 (alt="proposed" type="standard")
          cs                30 = 1.8.1 (type="standard")
          cy                30 = 1.8.1
          da                22.1 = 1.8.1 (type="standard")
          de__phonebook     30 = 2.0 (type="phonebook")
          de_AT_phonebook   30 = 27 (type="phonebook")
          dsb               30 = 26
          ee                30 = 21
          eo                30 = 1.8.1
          es                30 = 1.9.0 (type="standard")
          es__traditional   30 = 1.8.1 (type="traditional")
          et                30 = 26
          fa                22.1 = 1.8.1
          fi                22.1 = 1.8.1 (type="standard" alt="proposed")
          fi__phonebook     22.1 = 1.8.1 (type="phonebook")
          fil               30 = 1.9.0 (type="standard") = 1.8.1
          fo                22.1 = 1.8.1 (alt="proposed" type="standard")
          fr_CA             30 = 1.9.0
          gu                30 = 28 ("standard" wo [reorder Gujr..]) = 1.9.0
          ha                30 = 1.9.0
          haw               30 = 24
          he                30 = 28 (without [reorder Hebr]) = 23
          hi                30 = 28 (without [reorder Deva..]) = 1.9.0
          hr                30 = 28 ("standard" wo [reorder Latn Cyrl]) = 1.9.0
          hu                22.1 = 1.8.1 (alt="proposed" type="standard")
          hy                30 = 28 (without [reorder Armn]) = 1.8.1
          ig                30 = 1.8.1
          is                22.1 = 1.8.1 (type="standard")
          ja                22.1 = 1.8.1 (type="standard")
          kk                30 = 28 (without [reorder Cyrl])
          kl                22.1 = 1.8.1 (type="standard")
          kn                30 = 28 ("standard" wo [reorder Knda..]) = 1.9.0
          ko                22.1 = 1.8.1 (type="standard")
          kok               30 = 28 (without [reorder Deva..]) = 1.8.1
          lkt               30 = 25
          ln                30 = 2.0 (type="standard") = 1.8.1
          lt                22.1 = 1.9.0
          lv                22.1 = 1.9.0 (type="standard") = 1.8.1
          mk                30 = 28 (without [reorder Cyrl])
          ml                22.1 = 1.9.0
          mr                30 = 28 (without [reorder Deva..]) = 1.8.1
          mt                22.1 = 1.9.0
          nb                22.1 = 2.0   (type="standard")
          nn                22.1 = 2.0   (type="standard")
          nso           [*] 26 = 1.8.1
          om                22.1 = 1.8.1
          or                30 = 28 (without [reorder Orya..]) = 1.9.0
          pa                22.1 = 1.8.1
          pl                30 = 1.8.1
          ro                30 = 1.9.0 (type="standard")
          sa            [*] 1.9.1 = 1.8.1 (type="standard" alt="proposed")
          se                22.1 = 1.8.1 (type="standard")
          si                30 = 28 ("standard" wo [reorder Sinh..]) = 1.9.0
          si__dictionary    30 = 28 ("dictionary" wo [reorder Sinh..]) = 1.9.0
          sk                22.1 = 1.9.0 (type="standard")
          sl                22.1 = 1.8.1 (type="standard" alt="proposed")
          sq                22.1 = 1.8.1 (alt="proposed" type="standard")
          sr                30 = 28 (without [reorder Cyrl])
          sr_Latn           30 = 28 (type="standard": [import hr])
          sv                22.1 = 1.9.0 (type="standard")
          sv__reformed      22.1 = 1.8.1 (type="reformed")
          ta                22.1 = 1.9.0
          te                30 = 28 (without [reorder Telu..]) = 1.9.0
          th                22.1 = 22
          tn            [*] 26 = 1.8.1
          to                22.1 = 22
          tr                22.1 = 1.8.1 (type="standard")
          uk                30 = 28 (without [reorder Cyrl])
          ug_Cyrl           https://en.wikipedia.org/wiki/Uyghur_Cyrillic_alphabet
          ur                22.1 = 1.9.0
          vi                22.1 = 1.8.1
          vo                30 = 25
          wae               30 = 2.0
          wo            [*] 1.9.1 = 1.8.1
          yo                30 = 1.8.1
          zh                22.1 = 1.8.1 (type="standard")
          zh__big5han       22.1 = 1.8.1 (type="big5han")
          zh__gb2312han     22.1 = 1.8.1 (type="gb2312han")
          zh__pinyin        22.1 = 2.0   (type='pinyin' alt='short')
          zh__stroke        22.1 = 1.9.1 (type='stroke' alt='short')
          zh__zhuyin        22.1 = 22    (type='zhuyin' alt='short')
        --------------------------------------------------------------------

[*] http://www.unicode.org/repos/cldr/tags/latest/seed/collation/

# AUTHOR

The Unicode::Collate::Locale module for perl was written by SADAHIRO Tomoyuki, <SADAHIRO@cpan.org>. This module is Copyright(C) 2004-2017, SADAHIRO Tomoyuki. Japan. All rights reserved.

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

# SEE ALSO

Unicode Collation Algorithm - UTS #10

  http://www.unicode.org/reports/tr10/

The Default Unicode Collation Element Table (DUCET)

  http://www.unicode.org/Public/UCA/latest/allkeys.txt

Unicode Locale Data Markup Language (LDML) - UTS #35

  http://www.unicode.org/reports/tr35/

CLDR - Unicode Common Locale Data Repository

  http://cldr.unicode.org/

Unicode::Collate
Unicode::Normalize

Unicode::Collate::Locale - Linguistic tailoring for DUCET via Unicode::Collate