Unicode::Collate::Locale(3) Linguistic tailoring for DUCET via Unicode::Collate


use Unicode::Collate::Locale;
$Collator = Unicode::Collate::Locale->
new(locale => $locale_name, %tailoring);
@sorted = $Collator->sort(@not_sorted);
$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.


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


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 => 'FR')" returns a collator tailored for French.

$locale_name may be suffixed with a Unicode script code (four-letter), a Unicode region 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 French, which ignores diacritics and case difference (i.e. level 1), with reversed case ordering and no normalization.

        level => 1,
        locale => 'fr',
        upper_before_lower => 1,
        normalization => undef

Overriding a behavior already tailored by "locale" is disallowed if such a tailoring is passed to "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 => 'ca')->change(backwards => undef)
    new(locale => 'da')->change(upper_before_lower => 0)
    new(locale => 'ja')->change(overrideCJK => undef)


"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:

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.
(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
      bg                Bulgarian
      bn                Bengali
      bs                Bosnian
      bs_Cyrl           Bosnian in Cyrillic (tailored as Serbian)
      ca                Catalan
      cs                Czech
      cy                Welsh
      da                Danish
      de__phonebook     German (umlaut as 'ae', 'oe', 'ue')
      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                French
      gu                Gujarati
      ha                Hausa
      haw               Hawaiian
      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
      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
      ru                Russian
      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
      uk                Ukrainian
      ur                Urdu
      vi                Vietnamese
      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 chr (Cherokee), de (German), en (English), ga (Irish), id (Indonesian), it (Italian), ka (Georgian), ms (Malay), nl (Dutch), pt (Portuguese), st (Southern Sotho), sw (Swahili), xh (Xhosa), zu (Zulu).


[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.

Note: 'pinyin' is in latin, 'zhuyin' is in bopomofo.


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.


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.


The Unicode::Collate::Locale module for perl was written by SADAHIRO Tomoyuki, <[email protected]>. This module is Copyright(C) 2004-2013, 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.