Perl 5 version 22.1 documentation



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


  1. use Unicode::Collate::Locale;
  2. #construct
  3. $Collator = Unicode::Collate::Locale->
  4. new(locale => $locale_name, %tailoring);
  5. #sort
  6. @sorted = $Collator->sort(@not_sorted);
  7. #compare
  8. $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. 1. language with a variant code
  2. 2. language with a script code
  3. 3. language with a region code
  4. 4. language
  5. 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.

  1. Unicode::Collate::Locale->new(
  2. level => 1,
  3. locale => 'fr',
  4. upper_before_lower => 1,
  5. normalization => undef
  6. )

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

  1. Unicode::Collate::Locale->new(
  2. locale => 'da',
  3. upper_before_lower => 0, # causes error as reserved by 'da'
  4. )

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

  1. new(locale => 'ca')->change(backwards => undef)
  2. new(locale => 'da')->change(upper_before_lower => 0)
  3. 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:

  • $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

  1. locale name description
  2. --------------------------------------------------------------
  3. af Afrikaans
  4. ar Arabic
  5. as Assamese
  6. az Azerbaijani (Azeri)
  7. be Belarusian
  8. bg Bulgarian
  9. bn Bengali
  10. bs Bosnian
  11. bs_Cyrl Bosnian in Cyrillic (tailored as Serbian)
  12. ca Catalan
  13. cs Czech
  14. cy Welsh
  15. da Danish
  16. de__phonebook German (umlaut as 'ae', 'oe', 'ue')
  17. ee Ewe
  18. eo Esperanto
  19. es Spanish
  20. es__traditional Spanish ('ch' and 'll' as a grapheme)
  21. et Estonian
  22. fa Persian
  23. fi Finnish (v and w are primary equal)
  24. fi__phonebook Finnish (v and w as separate characters)
  25. fil Filipino
  26. fo Faroese
  27. fr French
  28. gu Gujarati
  29. ha Hausa
  30. haw Hawaiian
  31. hi Hindi
  32. hr Croatian
  33. hu Hungarian
  34. hy Armenian
  35. ig Igbo
  36. is Icelandic
  37. ja Japanese [1]
  38. kk Kazakh
  39. kl Kalaallisut
  40. kn Kannada
  41. ko Korean [2]
  42. kok Konkani
  43. ln Lingala
  44. lt Lithuanian
  45. lv Latvian
  46. mk Macedonian
  47. ml Malayalam
  48. mr Marathi
  49. mt Maltese
  50. nb Norwegian Bokmal
  51. nn Norwegian Nynorsk
  52. nso Northern Sotho
  53. om Oromo
  54. or Oriya
  55. pa Punjabi
  56. pl Polish
  57. ro Romanian
  58. ru Russian
  59. sa Sanskrit
  60. se Northern Sami
  61. si Sinhala
  62. si__dictionary Sinhala (U+0DA5 = U+0DA2,0DCA,0DA4)
  63. sk Slovak
  64. sl Slovenian
  65. sq Albanian
  66. sr Serbian
  67. sr_Latn Serbian in Latin (tailored as Croatian)
  68. sv Swedish (v and w are primary equal)
  69. sv__reformed Swedish (v and w as separate characters)
  70. ta Tamil
  71. te Telugu
  72. th Thai
  73. tn Tswana
  74. to Tonga
  75. tr Turkish
  76. uk Ukrainian
  77. ur Urdu
  78. vi Vietnamese
  79. wae Walser
  80. wo Wolof
  81. yo Yoruba
  82. zh Chinese
  83. zh__big5han Chinese (ideographs: big5 order)
  84. zh__gb2312han Chinese (ideographs: GB-2312 order)
  85. zh__pinyin Chinese (ideographs: pinyin order) [3]
  86. zh__stroke Chinese (ideographs: stroke order) [3]
  87. zh__zhuyin Chinese (ideographs: zhuyin order) [3]
  88. --------------------------------------------------------------

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/, 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, <>. 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.