Cldr v2.18.0 Cldr.Locale View Source

Functions to parse and normalize locale names into a structure locale represented by a Cldr.LanguageTag.

CLDR represents localisation data organized into locales, with each locale being identified by a locale name that is formatted according to RFC5646.

In practise, the CLDR data utilizes a simple subset of locale name formats being:

  • a Language code such as en or fr

  • a Language code and Tertitory code such as en-GB

  • a Language code and Script such as zh-Hant

  • and in only two cases a Language code, Territory code and Variant such as ca-ES-VALENCIA and en-US-POSIX.

The RFC defines a language tag as:

A language tag is composed from a sequence of one or more "subtags", each of which refines or narrows the range of language identified by the overall tag. Subtags, in turn, are a sequence of alphanumeric characters (letters and digits), distinguished and separated from other subtags in a tag by a hyphen ("-", [Unicode] U+002D)

Therefore Cldr uses the hyphen ("-", [Unicode] U+002D) as the subtag separator. On certain platforms, including POSIX platforms, the subtag separator is a "_" (underscore) rather than a "-" (hyphen). Where appropriate, Cldr will transliterate any underscore into a hyphen before parsing or processing.

Locale name validity

When validating a locale name, Cldr will attempt to match the requested locale name to a configured locale. Therefore Cldr.Locale.new/2 may return an {:ok, language_tag} tuple even when the locale returned does not exactly match the requested locale name. For example, the following attempts to create a locale matching the non-existent "english as spoken in Spain" local name. Here Cldr will match to the nearest configured locale, which in this case will be "en".

iex> Cldr.Locale.new("en-ES", TestBackend.Cldr)
{:ok, %Cldr.LanguageTag{
  backend: TestBackend.Cldr,
  canonical_locale_name: "en-Latn-ES",
  cldr_locale_name: "en",
  extensions: %{},
  gettext_locale_name: "en",
  language: "en",
  locale: %{},
  private_use: [],
  rbnf_locale_name: "en",
  requested_locale_name: "en-ES",
  script: "Latn",
  territory: :ES,
  transform: %{},
  language_variant: nil
}}

Matching locales to requested locale names

When attempting to match the requested locale name to a configured locale, Cldr attempt to match against a set of reductions in the following order and will return the first match:

  • language, script, territory, variant
  • language, territory, variant
  • language, script, variant
  • language, variant
  • language, script, territory
  • language, territory
  • language, script
  • language
  • requested locale name
  • nil

Therefore matching is tolerant of a request for unknown scripts, territories and variants. Only the requested language is a requirement to be matched to a configured locale.

Substitutions for Obsolete and Deprecated locale names

CLDR provides data to help manage the transition from obsolete or deprecated locale names to current names. For example, the following requests the locale name "mo" which is the deprecated code for "Moldovian". The replacement code is "ro" (Romanian).

iex> Cldr.Locale.new("mo", TestBackend.Cldr)
{:ok, %Cldr.LanguageTag{
  backend: TestBackend.Cldr,
  extensions: %{},
  gettext_locale_name: nil,
  language: "ro",
  language_subtags: [],
  language_variant: nil,
  locale: %{}, private_use: [],
  rbnf_locale_name: "ro",
  requested_locale_name: "mo",
  script: "Latn",
  transform: %{},
  canonical_locale_name: "ro-Latn-RO",
  cldr_locale_name: "ro",
  territory: :RO
}}

Likely subtags

CLDR also provides data to indetify the most likely subtags for a requested locale name. This data is based on the default content data, the population data, and the the suppress-script data in [BCP47]. It is heuristically derived, and may change over time. For example, when requesting the locale "en", the following is returned:

iex> Cldr.Locale.new("en", TestBackend.Cldr)
{:ok, %Cldr.LanguageTag{
  backend: TestBackend.Cldr,
  canonical_locale_name: "en-Latn-US",
  cldr_locale_name: "en",
  extensions: %{},
  gettext_locale_name: "en",
  language: "en",
  locale: %{},
  private_use: [],
  rbnf_locale_name: "en",
  requested_locale_name: "en",
  script: "Latn",
  territory: :US,
  transform: %{},
  language_variant: nil
}}

Which shows that a the likely subtag for the script is "Latn" and the likely territory is "US".

Using the example for Substitutions above, we can see the result of combining substitutions and likely subtags for locale name "mo" returns the current language code of "ro" as well as the likely territory code of "MD" (Moldova).

Unknown territory codes

Whilst Cldr is tolerant of invalid territory codes, it is also important that such invalid codes not shadow the potential replacement of deprecated codes nor the insertion of likely subtags. Therefore invalid territory codes are ignored during this process. For example requesting a locale name "en-XX" which requests the invalid territory "XX", the following will be returned:

iex> Cldr.Locale.new("en-XX", TestBackend.Cldr)
{:ok, %Cldr.LanguageTag{
  backend: TestBackend.Cldr,
  canonical_locale_name: "en-Latn-US",
  cldr_locale_name: "en",
  extensions: %{},
  gettext_locale_name: "en",
  language: "en",
  locale: %{},
  private_use: [],
  rbnf_locale_name: "en",
  requested_locale_name: "en",
  script: "Latn",
  territory: :US,
  transform: %{},
  language_variant: nil
}}

Locale extensions

Unicode defines the U extension which support defining the requested treatment of CLDR data formats. For example, a locale name can configure the requested:

  • calendar to be used for dates
  • collation
  • currency
  • currency format
  • number system
  • first day of the week
  • 12-hour or 24-hour time
  • time zone
  • and many other items

For example, the following locale name will request the use of the timezone Australia/Sydney, and request the use of accounting format when formatting currencies:

iex> MyApp.Cldr.validate_locale "en-AU-u-tz-ausyd-cf-account"
{
  :ok,
  %Cldr.LanguageTag{
    backend: MyApp.Cldr,
    canonical_locale_name: "en-Latn-AU",
    cldr_locale_name: "en-AU",
    extensions: %{},
    gettext_locale_name: "en",
    language: "en",
    language_subtags: '',
    language_variant: nil,
    locale: %Cldr.LanguageTag.U{
      alternative_collation: nil,
      backward_level2: nil,
      calendar: nil,
      case_first: nil,
      case_level: nil,
      collation: nil,
      currency: nil,
      currency_format: :accounting,
      emoji_style: nil,
      first_day_of_week: nil,
      hiragana_quarternary: nil,
      hour_cycle: nil,
      line_break_style: nil,
      line_break_word: nil,
      measurement_system: nil,
      normalization: nil,
      number_system: nil,
      numeric: nil,
      region_override: nil,
      reorder: nil,
      sentence_break_supression: nil,
      strength: nil,
      subdivision: nil,
      timezone: "Australia/Sydney",
      variable_top: nil,
      variant: nil
    },
    private_use: '',
    rbnf_locale_name: "en",
    requested_locale_name: "en-AU",
    script: "Latn",
    territory: :AU,
    transform: %{}
  }
}

Link to this section Summary

Types

The name of a locale in a string format

Functions

Replace empty subtags within a Cldr.LanguageTag.t/0 with the most likely subtag.

Returns an error tuple for an invalid locale alias.

Return a map of the known aliases for Language, Script and Territory

Return a map of the aliases for a given alias key and type

Parses a locale name and returns a Cldr.LanguageTag struct that represents a locale.

Parses a locale name and returns a Cldr.LanguageTag struct that represents a locale or raises on error.

Returns an error tuple for an invalid gettext locale.

Returns the map of likely subtags.

Returns the likely substags, as a Cldr.LanguageTag, for a given locale name.

Returns an error tuple for an invalid locale.

Return a locale name from a Cldr.LanguageTag

Return a locale name by combining language, script, territory and variant parameters

See Cldr.Config.locale_name_from_posix/1.

See Cldr.Config.locale_name_to_posix/1.

Normalize the casing of a locale name.

Substitute deprectated subtags with a Cldr.LanguageTag with their non-deprecated alternatives.

Returns the effective territory for a locale.

Link to this section Types

Specs

language() :: String.t() | nil

Specs

locale_name() :: String.t()

The name of a locale in a string format

Specs

script() :: String.t() | nil

Specs

subtags() :: [String.t(), ...] | []

Specs

territory() :: String.t() | nil

Specs

variant() :: String.t() | nil

Link to this section Functions

Link to this function

add_likely_subtags(language_tag)

View Source

Replace empty subtags within a Cldr.LanguageTag.t/0 with the most likely subtag.

Options

A subtag is called empty if it has a missing script or territory subtag, or it is a base language subtag with the value und. In the description below, a subscript on a subtag x indicates which tag it is from: x<sub>s</sub> is in the source, x<sub>m</sub> is in a match, and x<sub>r</sub> is in the final result.

Lookup

Lookup each of the following in order, and stops on the first match:

  • language<sub>s</sub>-script<sub>s</sub>-region<sub>s</sub>
  • language<sub>s</sub>-region<sub>s</sub>
  • language<sub>s</sub>-script<sub>s</sub>
  • language<sub>s</sub>
  • und-script<sub>s</sub>

Returns

  • If there is no match,either return

    • an error value, or
    • the match for und
  • Otherwise there is a match = language<sub>m</sub>-script<sub>m</sub>-region<sub>m</sub>

  • Let x<sub>r</sub> = x<sub>s</sub> if x<sub>s</sub> is not empty, and x<sub>m</sub> otherwise.

  • Return the language tag composed of language<sub>r</sub>-script<sub>r</sub>-region<sub>r</sub> + variants + extensions .

Example

iex> Cldr.Locale.add_likely_subtags Cldr.LanguageTag.parse!("zh-SG")
%Cldr.LanguageTag{
  backend: nil,
  canonical_locale_name: nil,
  cldr_locale_name: nil,
  language_subtags: [],
  extensions: %{},
  gettext_locale_name: nil,
  language: "zh",
  locale: %{},
  private_use: [],
  rbnf_locale_name: nil,
  requested_locale_name: "zh-SG",
  script: "Hans",
  territory: :SG,
  transform: %{},
  language_variant: nil
}
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alias_error(locale_name, alias_name)

View Source

Specs

alias_error(locale_name() | Cldr.LanguageTag.t(), String.t()) ::
  {Cldr.UnknownLocaleError, String.t()}

Returns an error tuple for an invalid locale alias.

Options

Specs

aliases() :: map()

Return a map of the known aliases for Language, Script and Territory

Specs

aliases(locale_name(), atom()) :: map() | nil

Return a map of the aliases for a given alias key and type

Options

  • type is one of [:language, :region, :script, :variant, :zone]

  • key is the substitution key (a language, region, script, variant or zone)

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canonical_language_tag(locale_name, backend)

View Source

Parses a locale name and returns a Cldr.LanguageTag struct that represents a locale.

Arguments

Returns

  • {:ok, language_tag} or

  • {:eror, reason}

Method

  1. The language tag is parsed in accordance with RFC5646

  2. Any language, script or region aliases are replaced. This will replace any obsolete elements with current versions

  3. If a territory or script is not specified, a default is provided using the CLDR information returned by Cldr.Locale.likely_subtags/1

  4. A Cldr locale name is selected that is the nearest fit to the requested locale.

Example

iex> Cldr.Locale.canonical_language_tag("en", TestBackend.Cldr)
{
  :ok,
  %Cldr.LanguageTag{
    backend: TestBackend.Cldr,
    canonical_locale_name: "en-Latn-US",
    cldr_locale_name: "en",
    extensions: %{},
    gettext_locale_name: "en",
    language: "en",
    locale: %{},
    private_use: [],
    rbnf_locale_name: "en",
    requested_locale_name: "en",
    script: "Latn",
    territory: :US,
    transform: %{},
    language_variant: nil
  }
}
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canonical_language_tag!(language_tag, backend)

View Source

Specs

canonical_language_tag!(locale_name() | Cldr.LanguageTag.t(), Cldr.backend()) ::
  Cldr.LanguageTag.t() | none()

Parses a locale name and returns a Cldr.LanguageTag struct that represents a locale or raises on error.

Arguments

See Cldr.Locale.canonical_language_tag/2 for more information.

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gettext_locale_error(locale_name)

View Source

Specs

gettext_locale_error(locale_name() | Cldr.LanguageTag.t()) ::
  {Cldr.UnknownLocaleError, String.t()}

Returns an error tuple for an invalid gettext locale.

Options

Returns

  • {:error, {Cldr.UnknownLocaleError, message}}

Examples

iex> Cldr.Locale.gettext_locale_error :invalid
{Cldr.UnknownLocaleError, "The gettext locale :invalid is not known."}

Returns the map of likely subtags.

Note that not all locales are guaranteed to have likely subtags.

Example

Cldr.Locale.likely_subtags
%{
  "bez" => %Cldr.LanguageTag{
    backend: TestBackend.Cldr,
    canonical_locale_name: nil,
    cldr_locale_name: nil,
    extensions: %{},
    language: "bez",
    locale: %{},
    private_use: [],
    rbnf_locale_name: nil,
    requested_locale_name: nil,
    script: "Latn",
    territory: :TZ,
    transform: %{},
    language_variant: nil
  },
  "fuf" => %Cldr.LanguageTag{
    canonical_locale_name: nil,
    cldr_locale_name: nil,
    extensions: %{},
    language: "fuf",
    locale: %{},
    private_use: [],
    rbnf_locale_name: nil,
    requested_locale_name: nil,
    script: "Latn",
    territory: :GN,
    transform: %{},
    language_variant: nil
  },
  ...
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likely_subtags(locale_name)

View Source

Specs

likely_subtags(locale_name()) :: Cldr.LanguageTag.t() | nil

Returns the likely substags, as a Cldr.LanguageTag, for a given locale name.

Options

Examples

iex> Cldr.Locale.likely_subtags "en"
%Cldr.LanguageTag{
  backend: nil,
  canonical_locale_name: nil,
  cldr_locale_name: nil,
  extensions: %{},
  gettext_locale_name: nil,
  language: "en",
  locale: %{},
  private_use: [],
  rbnf_locale_name: nil,
  requested_locale_name: "en-Latn-US",
  script: "Latn",
  territory: :US,
  transform: %{},
  language_variant: nil
}
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locale_error(locale_name)

View Source

Specs

locale_error(locale_name() | Cldr.LanguageTag.t()) ::
  {Cldr.UnknownLocaleError, String.t()}

Returns an error tuple for an invalid locale.

Arguments

Returns

  • {:error, {Cldr.UnknownLocaleError, message}}

Examples

iex> Cldr.Locale.locale_error :invalid
{Cldr.UnknownLocaleError, "The locale :invalid is not known."}
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locale_name_from(language_tag)

View Source

Specs

locale_name_from(Cldr.LanguageTag.t()) :: locale_name()

Return a locale name from a Cldr.LanguageTag

Options

Example

iex> Cldr.Locale.locale_name_from Cldr.Locale.new!("en", TestBackend.Cldr)
"en-Latn-US"
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locale_name_from(language, script, territory, variant)

View Source

Specs

locale_name_from(
  language(),
  script(),
  Cldr.territory() | territory(),
  variant()
) :: locale_name()

Return a locale name by combining language, script, territory and variant parameters

Arguments

  • language, script, territory and variant are string representations, or nil, of the language subtags

Returns

  • The locale name constructed from the non-nil arguments joined by a "-"

Example

iex> Cldr.Locale.locale_name_from("en", "Latn", "001", nil)
"en-Latn-001"

iex> Cldr.Locale.locale_name_from("en", "Latn", :"001", nil)
"en-Latn-001"
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locale_name_from_posix(locale_name)

View Source

See Cldr.Config.locale_name_from_posix/1.

Link to this function

locale_name_to_posix(locale_name)

View Source

See Cldr.Config.locale_name_to_posix/1.

Link to this function

new(locale_name, backend)

View Source

See Cldr.Locale.canonical_language_tag/2.

Link to this function

new!(locale_name, backend)

View Source

See Cldr.Locale.canonical_language_tag!/2.

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normalize_locale_name(locale_name)

View Source

Specs

normalize_locale_name(locale_name()) :: locale_name()

Normalize the casing of a locale name.

Options

Returns

  • The normalized locale name as a String.t

Method

Locale names are case insensitive but certain common casing is followed in practise:

  • lower case for a language
  • capital case for a script
  • upper case for a region/territory

Note this function is intended to support only the CLDR locale names which have a format that is a subset of the full langauge tag specification.

For proper parsing of local names and language tags, see Cldr.Locale.canonical_language_tag/2

Examples

iex> Cldr.Locale.normalize_locale_name "zh_hant"
"zh-Hant"

iex> Cldr.Locale.normalize_locale_name "en_us"
"en-US"

iex> Cldr.Locale.normalize_locale_name "EN"
"en"

iex> Cldr.Locale.normalize_locale_name "ca_es_valencia"
"ca-ES-VALENCIA"
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put_gettext_locale_name(language_tag, backend)

View Source

Specs

put_gettext_locale_name(Cldr.LanguageTag.t(), Cldr.backend()) ::
  Cldr.LanguageTag.t()
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substitute_aliases(language_tag)

View Source

Substitute deprectated subtags with a Cldr.LanguageTag with their non-deprecated alternatives.

Arguments

Method

  • Replace any deprecated subtags with their canonical values using the alias data. Use the first value in the replacement list, if it exists. Language tag replacements may have multiple parts, such as shsr_Latn or moro_MD. In such a case, the original script and/or region/territory are retained if there is one. Thus sh_Arab_AQsr_Arab_AQ, not sr_Latn_AQ.

  • Remove the script code 'Zzzz' and the territory code 'ZZ' if they occur.

  • Get the components of the cleaned-up source tag (languages, scripts, and regions/territories), plus any variants and extensions.

Example

iex> Cldr.Locale.substitute_aliases Cldr.LanguageTag.Parser.parse!("mo")
%Cldr.LanguageTag{
  backend: nil,
  canonical_locale_name: nil,
  cldr_locale_name: nil,
  extensions: %{},
  gettext_locale_name: nil,
  language: "ro",
  language_subtags: [],
  language_variant: nil,
  locale: %{}, private_use: [],
  rbnf_locale_name: nil,
  requested_locale_name: "mo",
  script: nil, transform: %{},
  territory: nil
}
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territory_from_locale(language_tag)

View Source

Specs

territory_from_locale(Cldr.LanguageTag.t()) :: Cldr.territory()

Returns the effective territory for a locale.

Arguments

Returns

  • The territory to be used for localization purposes

Examples

iex> {:ok, locale} = Cldr.validate_locale("en-US", MyApp.Cldr)
iex> Cldr.Locale.territory_from_locale locale
:US

iex> {:ok, locale} = Cldr.validate_locale("en-US-u-rg-cazzzz", MyApp.Cldr)
iex> Cldr.Locale.territory_from_locale locale
:CA

iex> {:ok, locale} = Cldr.validate_locale("en-US-u-rg-xxxxx", MyApp.Cldr)
iex> Cldr.Locale.territory_from_locale locale
:US

Notes

A locale can reflect the desired territory to be used when determining region-specific defaults for items such as:

  • default currency,
  • default calendar and week data,
  • default time cycle, and
  • default measurement system and unit preferences

Territory information is stored in the locale in up to three different places:

  1. The :territory extracted from the locale name or defined by default for a given language. This is the typical use case when locale names such as en-US or es-AR are used.

  2. In some cases it might be desired to override the territory derived from the locale name. For example, the default territory for the language "en" is "US" but it may be desired to apply the defaults for the territory "AU" instead, without otherwise changing the localization intent. In this case the U extension is used to define a regional override

  3. Similarly, the [regional subdivision identifier] (https://unicode.org/reports/tr35/#UnicodeSubdivisionIdentifier) can be used to influence localization decisions. This identifier is not currently used in ex_cldr and dependent libraries however it is correctly parsed to support future use.

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territory_from_locale(locale, backend)

View Source

Specs

territory_from_locale(locale_name(), Cldr.backend()) ::
  Cldr.territory() | {:error, {module(), String.t()}}