View Source Cldr.Number.System (Cldr Numbers v2.32.3)

Number systems information is used to define different representations for numeric values to an end user. Numbering systems are defined in CLDR as one of two different types: algorithmic and numeric.

Numeric systems are simply a decimal based system that uses a predefined set of digits to represent numbers. Examples are Western digits (ASCII digits), Thai digits, Devanagari digits.

Algorithmic systems are more complex in nature, since the proper formatting and presentation of a numeric quantity is based on some algorithm or set of rules. Examples are Chinese numerals, Hebrew numerals, or Roman numerals.

In CLDR, the rules for presentation of numbers in an algorithmic system are defined using the rules based number formats (RBNF) which are implemented in Cldr.Number.Rbnf.

Number system attributes

Attributes for a number system map are as follows:

  • :id specifies the name of the number system that can be used to designate its use in formatting.
  • :type specifies whether the number system is algorithmic or numeric.
  • :digitsFor numeric systems, specifies the digits used to represent numbers, in order, starting from zero.
  • :rules specifies the RBNF ruleset to be used for formatting numbers from this number system. The rules specifier can contain simply a ruleset name, in which case the ruleset is assumed to be found in the rule set grouping "NumberingSystemRules". Alternatively, the specifier can denote a specific locale, ruleset grouping, and ruleset name, separated by slashes.

An example of a number system map is:

iex> Cldr.Number.System.number_systems()[:latn]
%{type: :numeric, digits: "0123456789"}

iex> Cldr.Number.System.number_systems()[:taml]
%{type: :algorithmic, rules: "tamil"}

Number system types

Each number system also categories number systems into various types:

  • :native defines the number system used for the native digits, usually defined as a part of the script used to write the language. :native number system can only be a numeric positional decimal-digit number system, using digits with General_Category=Decimal_Number. Note that In locales where the native number system is the default, it is assumed that the number system "latn" (Western digits 0-9) is always acceptable, and can be selected using the -nu keyword as part of a Unicode locale name.

  • :traditional defines the traditional numerals for a locale. This numbering system may be numeric or algorithmic. If the traditional number system is not defined, the native number system is used as a fallback.

  • :finance defines the number system used for financial quantities. This number system may be numeric or algorithmic. This is often used for ideographic languages such as Chinese, where it would be easy to alter an amount represented in the default number system simply by adding additional strokes. If the financial number system is not specified, the default number system is used as a fallback.

An example of a number system map for the :zh locale is:

iex> Cldr.Number.System.number_systems_for(:zh, MyApp.Cldr)
{:ok,
 %{default: :latn, native: :hanidec, traditional: :hans, finance: :hansfin}}

This indicates that for the locale :zh, the number systems :latn, :hanidec, :hans and :hansfin are supported. These number systems are a mix of nuemeric systems and algorithmic systems.

Specifying the number system in a locale name

The types defined for other number systems can be used in a Unicode locale identifier to select the proper number system without having to know the specific number system by name. For example:

  • To select the Hindi language using the native digits for numeric formatting, use locale ID: "hi-IN-u-nu-native".

  • To select the Chinese language using the appropriate financial numerals, use locale ID: "zh-u-nu-finance".

  • To select the Tamil language using the traditional Tamil numerals, use locale ID: "ta-u-nu-traditio".

  • To select the Arabic language using western digits 0-9, use locale ID: "ar-u-nu-latn".

Summary

Types

system_name()
types()

Functions

algorithmic_systems()

Returns a map of the number systems that are algorithmic.

default_number_system_type()

Return the default number system type name.

default_rbnf_rule(system_name, backend)

Returns the default RBNF rule name for an algorithmic number system.

generate_transliteration_map(from, to)

Generate a transliteration map between two character classes.

known_number_system_types(backend)

See Cldr.known_number_system_types/1.

known_number_systems()

See Cldr.known_number_systems/0.

number_system_digits(system_name)

Returns the digits for a number system as a string.

number_system_digits!(system_name)

Returns digits for a number system, or raises an exception.

number_system_for(locale, system_name, backend)

Returns the actual number system from a number system type.

number_system_from_locale(locale)

Returns the number system from a language tag or locale name.

number_system_from_locale(locale, backend)

Returns the default number system from a language tag or locale name.

number_system_names_for(locale, backend)

Returns the names of the number systems available for a locale.

number_system_names_for!(locale, backend)

Returns the names of the number systems available for a locale or raises an exception.

number_systems()

Return a map of all CLDR number systems and their definitions.

number_systems_for(locale, backend)

Returns the number system types mapped to a number system name for a locale.

number_systems_for!(locale, backend)

Returns the number system types mapped to a number system name for a locale or raises an exception.

number_systems_like(locale, number_system, backend)

Returns locale and number systems that have the same digits and separators as the supplied one.

numeric_systems()

Returns a map of the number systems that have their own digit character representations.

system_name_from(system_name, locale, backend)

Returns a number system name for a given locale and number system reference.

system_name_from!(system_name, locale, backend)

Returns a number system name for a given locale and number system reference or raises an exception.

systems_with_digits() deprecated

See Cldr.Number.System.numeric_systems/0.

to_system(number, system_name, backend)

Converts a number into the representation of a non-latin number system.

to_system!(number, system_name, backend)

Converts a number into the representation of a non-latin number system or raises an exception.

unknown_number_system_for_locale_error(number_system, locale, valid_number_systems)

Returns an error tuple for an number system unknown to a given locale.

Types

Link to this type

system_name()

View Source 
@type system_name() :: atom()
Link to this type

types()

View Source 
@type types() :: :default | :native | :traditional | :finance

Functions

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algorithmic_systems()

View Source (since 2.32.0)

Returns a map of the number systems that are algorithmic.

Algorithmic number systems don't have decimal digits. Numbers are formed by algorithm using rules based number formats.

The :rules field contains the name of the RBNF rule that will be used with formatting a number with format: :standard (which is also the default when no :format is specified).

See also Cldr.Number.System.numeric_systems/0.

Example 

==> Cldr.Number.System.algorithmic_systems()
%{
  roman: %{type: :algorithmic, rules: "roman-upper"},
  armn: %{type: :algorithmic, rules: "armenian-upper"},
  armnlow: %{type: :algorithmic, rules: "armenian-lower"},
  cyrl: %{type: :algorithmic, rules: "cyrillic-lower"},
  ethi: %{type: :algorithmic, rules: "ethiopic"},
  geor: %{type: :algorithmic, rules: "georgian"},
  grek: %{type: :algorithmic, rules: "greek-upper"},
  greklow: %{type: :algorithmic, rules: "greek-lower"},
  hanidays: %{
    type: :algorithmic,
    rules: "zh/SpelloutRules/spellout-numbering-days"
  },
  hans: %{type: :algorithmic, rules: "zh/SpelloutRules/spellout-cardinal"},
  hansfin: %{
    type: :algorithmic,
    rules: "zh/SpelloutRules/spellout-cardinal-financial"
  },
  ...
}
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default_number_system_type()

View Source

Return the default number system type name.

The default number system type is :default. Note that this is not the number system itself but the type of the number system.

Example 

iex> Cldr.Number.System.default_number_system_type()
:default
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default_rbnf_rule(system_name, backend)

View Source

Returns the default RBNF rule name for an algorithmic number system.

Arguments

Returns

  • {:ok, {module, rule_function, locale}} or

  • {:error, {module(), reason}}

Example 

iex> Cldr.Number.System.default_rbnf_rule(:taml, MyApp.Cldr)
{:ok, {MyApp.Cldr.Rbnf.NumberSystem, :tamil, :und}}

iex> Cldr.Number.System.default_rbnf_rule(:hebr, MyApp.Cldr)
{:ok, {MyApp.Cldr.Rbnf.NumberSystem, :hebrew, :und}}

iex> Cldr.Number.System.default_rbnf_rule(:jpanfin, MyApp.Cldr)
{:ok, {MyApp.Cldr.Rbnf.Spellout, :spellout_cardinal_financial, :ja}}

iex> Cldr.Number.System.default_rbnf_rule(:latn, MyApp.Cldr)
{:error,
 {Cldr.UnknownNumberSystemError, "The number system :latn is not algorithmic"}}
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generate_transliteration_map(from, to)

View Source

Generate a transliteration map between two character classes.

Arguments

  • from is any String.t() intended to represent the digits of a number system but that's not a requirement.

  • to is any String.t() that is the same length as from intended to represent the digits of a number system.

Returns

  • A map where the keys are the graphemes in from and the values are the graphemes in to or

  • {:error, {exception, reason}}

Examples 

iex> Cldr.Number.System.generate_transliteration_map("0123456789", "9876543210")
%{
  "0" => "9",
  "1" => "8",
  "2" => "7",
  "3" => "6",
  "4" => "5",
  "5" => "4",
  "6" => "3",
  "7" => "2",
  "8" => "1",
  "9" => "0"
}

iex> Cldr.Number.System.generate_transliteration_map("0123456789", "987654321")
{:error,
 {ArgumentError, "\"0123456789\" and \"987654321\" aren't the same length"}}
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known_number_system_types(backend)

View Source

See Cldr.known_number_system_types/1.

Link to this function

known_number_systems()

View Source

See Cldr.known_number_systems/0.

Link to this function

number_system_digits(system_name)

View Source 
@spec number_system_digits(system_name()) ::
  {:ok, String.t()} | {:error, {module(), String.t()}}

Returns the digits for a number system as a string.

Arguments

Returns

  • {:ok, string_of_digits} or

  • {:error, {exception, reason}}.

Examples 

iex> Cldr.Number.System.number_system_digits(:latn)
{:ok, "0123456789"}

iex> Cldr.Number.System.number_system_digits(:nope)
{:error, {Cldr.UnknownNumberSystemError, "The number system :nope is not known"}}
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number_system_digits!(system_name)

View Source 
@spec number_system_digits!(system_name()) :: String.t() | no_return()

Returns digits for a number system, or raises an exception.

Arguments

Returns

  • A string of the number systems digits or

  • raises an exception

Examples 

iex> Cldr.Number.System.number_system_digits! :latn
"0123456789"

Cldr.Number.System.number_system_digits! :nope
** (Cldr.UnknownNumberSystemError) The number system :nope is not known or does not have digits
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number_system_for(locale, system_name, backend)

View Source 
@spec number_system_for(Cldr.Locale.locale_reference(), system_name(), Cldr.backend()) ::
  {:ok, map()} | {:error, {module(), String.t()}}

Returns the actual number system from a number system type.

Arguments

Returns

  • {:ok, number_system_map} or

  • {:error, {exception, reason}}.

Notes

This function will decode a number system type into the actual number system. If the number system provided can't be decoded it is returned as is.

Examples 

iex> Cldr.Number.System.number_system_for("th", :latn, TestBackend.Cldr)
{:ok, %{digits: "0123456789", type: :numeric}}

iex> Cldr.Number.System.number_system_for("en", :default, TestBackend.Cldr)
{:ok, %{digits: "0123456789", type: :numeric}}

iex> Cldr.Number.System.number_system_for("he", :traditional, TestBackend.Cldr)
{:ok, %{rules: "hebrew", type: :algorithmic}}

iex> Cldr.Number.System.number_system_for("en", :finance, TestBackend.Cldr)
{
  :error,
  {
    Cldr.UnknownNumberSystemError,
    "The number system :finance is unknown for the locale named :en. Valid number systems are %{default: :latn, native: :latn}"
  }
}

iex> Cldr.Number.System.number_system_for("en", :native, TestBackend.Cldr)
{:ok, %{digits: "0123456789", type: :numeric}}
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number_system_from_locale(locale)

View Source 
@spec number_system_from_locale(Cldr.Locale.locale_reference()) ::
  system_name() | {:error, {module(), String.t()}}

Returns the number system from a language tag or locale name.

Arguments

Returns

  • A number system name as an atom.

Examples 

iex> {:ok, locale} = MyApp.Cldr.validate_locale("en-US-u-nu-thai")
iex> Cldr.Number.System.number_system_from_locale(locale)
:thai

iex> {:ok, locale} = MyApp.Cldr.validate_locale("en-US")
iex> Cldr.Number.System.number_system_from_locale(locale)
:latn

iex> Cldr.Number.System.number_system_from_locale("ar")
:arab
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number_system_from_locale(locale, backend)

View Source 
@spec number_system_from_locale(Cldr.Locale.locale_reference(), Cldr.backend()) ::
  system_name() | {:error, {module(), String.t()}}

Returns the default number system from a language tag or locale name.

Arguments

Returns

  • A number system name as an atom.

Examples 

iex> Cldr.Number.System.number_system_from_locale("en-US-u-nu-thai", MyApp.Cldr)
:thai

iex> Cldr.Number.System.number_system_from_locale(:"en-US", MyApp.Cldr)
:latn
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number_system_names_for(locale, backend)

View Source 
@spec number_system_names_for(Cldr.Locale.locale_reference(), Cldr.backend()) ::
  {:ok, [atom()]} | {:error, {module(), String.t()}}

Returns the names of the number systems available for a locale.

Arguments

  • locale is any locale returned by Cldr.Locale.new!/2.

  • backend is any Cldr backend. That is, any module that contains use Cldr.

Returns

  • {:ok, list_of_number_system_names} or

  • {:error, {exception, reason}}.

Examples 

iex> Cldr.Number.System.number_system_names_for("en", TestBackend.Cldr)
{:ok, [:latn]}

iex> Cldr.Number.System.number_system_names_for("th", TestBackend.Cldr)
{:ok, [:latn, :thai]}

iex> Cldr.Number.System.number_system_names_for("he", TestBackend.Cldr)
{:ok, [:latn, :hebr]}

iex> Cldr.Number.System.number_system_names_for("zz", TestBackend.Cldr)
{:error, {Cldr.InvalidLanguageError, "The language \"zz\" is invalid"}}
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number_system_names_for!(locale, backend)

View Source 
@spec number_system_names_for!(Cldr.Locale.locale_reference(), Cldr.backend()) ::
  [system_name()] | no_return()

Returns the names of the number systems available for a locale or raises an exception.

Arguments

Returns

  • list_of_number_system_names or

  • raises and exception.

Examples 

iex> Cldr.Number.System.number_system_names_for!("en", TestBackend.Cldr)
[:latn]

iex> Cldr.Number.System.number_system_names_for!("th", TestBackend.Cldr)
[:latn, :thai]

iex> Cldr.Number.System.number_system_names_for!("he", TestBackend.Cldr)
[:latn, :hebr]
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number_systems()

View Source 
@spec number_systems() :: map()

Return a map of all CLDR number systems and their definitions.

Example 

iex> Cldr.Number.System.number_systems() |> Enum.count
88
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number_systems_for(locale, backend)

View Source 
@spec number_systems_for(Cldr.Locale.locale_reference(), Cldr.backend()) ::
  {:ok, map()} | {:error, {module(), String.t()}}

Returns the number system types mapped to a number system name for a locale.

When formatting a nummber it is acceptable to refer to either the nuumber system type or the number system name.

Arguments

Returns

  • {:ok, number_system_map} or

  • {:error, {exception, reason}}.

Examples 

iex> Cldr.Number.System.number_systems_for(:en)
{:ok, %{default: :latn, native: :latn}}

iex> Cldr.Number.System.number_systems_for(:th)
{:ok, %{default: :latn, native: :thai}}

iex> Cldr.Number.System.number_systems_for("zz", TestBackend.Cldr)
{:error, {Cldr.InvalidLanguageError, "The language \"zz\" is invalid"}}
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number_systems_for!(locale, backend)

View Source 
@spec number_systems_for!(Cldr.Locale.locale_reference(), Cldr.backend()) ::
  map() | no_return()

Returns the number system types mapped to a number system name for a locale or raises an exception.

Arguments

Returns

  • number_system_map or

  • raises an exception.

Examples 

iex> Cldr.Number.System.number_systems_for!("en")
%{default: :latn, native: :latn}

iex> Cldr.Number.System.number_systems_for!("th", TestBackend.Cldr)
%{default: :latn, native: :thai}
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number_systems_like(locale, number_system, backend)

View Source 
@spec number_systems_like(
  Cldr.Locale.locale_reference(),
  system_name(),
  Cldr.backend()
) ::
  {:ok, list()} | {:error, {module(), String.t()}}

Returns locale and number systems that have the same digits and separators as the supplied one.

Arguments

Returns

Notes

  • Transliterating between locale & number systems is expensive. To avoid unnecessary transliteration we look for locale and number systems that have the same digits and separators. Typically we are comparing to locale "en" and number system "latn" since this is what the number formatting routines use as placeholders.

Examples 

==> import Cldr.LanguageTag.Sigil
==> Cldr.Number.System.number_systems_like(:en, :latn, MyApp.Cldr)
{:ok,
  [
    {~l[en], :latn},
    {~l[en-IN], :latn},
    {~l[ta], :latn},
    {~l[th], :latn},
    {~l[zh], :latn}
  ]
}
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numeric_systems()

View Source

Returns a map of the number systems that have their own digit character representations.

See also Cldr.Number.System.algorithmic_systems/0.

Example 

==> Cldr.Number.System.numeric_systems()
%{
  gonm: %{type: :numeric, digits: "๐‘ต๐‘ต‘๐‘ต’๐‘ต“๐‘ต”๐‘ต•๐‘ต–๐‘ต—๐‘ต˜๐‘ต™"},
  mathdbl: %{type: :numeric, digits: "๐Ÿ˜๐Ÿ™๐Ÿš๐Ÿ›๐Ÿœ๐Ÿ๐Ÿž๐ŸŸ๐Ÿ ๐Ÿก"},
  bhks: %{type: :numeric, digits: "๐‘ฑ๐‘ฑ‘๐‘ฑ’๐‘ฑ“๐‘ฑ”๐‘ฑ•๐‘ฑ–๐‘ฑ—๐‘ฑ˜๐‘ฑ™"},
  deva: %{type: :numeric, digits: "เฅฆเฅงเฅจเฅฉเฅชเฅซเฅฌเฅญเฅฎเฅฏ"},
  adlm: %{type: :numeric, digits: "๐žฅ๐žฅ‘๐žฅ’๐žฅ“๐žฅ”๐žฅ•๐žฅ–๐žฅ—๐žฅ˜๐žฅ™"},
  telu: %{type: :numeric, digits: "เฑฆเฑงเฑจเฑฉเฑชเฑซเฑฌเฑญเฑฎเฑฏ"},
  cakm: %{type: :numeric, digits: "๐‘„ถ๐‘„ท๐‘„ธ๐‘„น๐‘„บ๐‘„ป๐‘„ผ๐‘„ฝ๐‘„พ๐‘„ฟ"},
  mathsans: %{
    type: :numeric,
    digits: "๐Ÿข๐Ÿฃ๐Ÿค๐Ÿฅ๐Ÿฆ๐Ÿง๐Ÿจ๐Ÿฉ๐Ÿช๐Ÿซ"
  },
  nkoo: %{type: :numeric, digits: "฿€฿฿‚฿ƒ฿„฿…฿†฿‡฿ˆ฿‰"},
  ...
}
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system_name_from(system_name, locale, backend)

View Source 
@spec system_name_from(system_name(), Cldr.Locale.locale_reference(), Cldr.backend()) ::
  {:ok, atom()} | {:error, {module(), String.t()}}

Returns a number system name for a given locale and number system reference.

Arguments

Returns

  • {:ok, number_system_name} or

  • {:error, {exception, reason}}.

Notes

Number systems can be references in one of two ways:

  • As a number system type such as :default, :native, :traditional and :finance. This allows references to a number system for a locale in a consistent fashion for a given use

  • WIth the number system name directly, such as :latn, :arab or any of the other 70 or so

This function dereferences the supplied system_name and returns the actual system name.

Examples 

ex> Cldr.Number.System.system_name_from(:default, "en", TestBackend.Cldr)
{:ok, :latn}

iex> Cldr.Number.System.system_name_from("latn", "en", TestBackend.Cldr)
{:ok, :latn}

iex> Cldr.Number.System.system_name_from(:native, "en", TestBackend.Cldr)
{:ok, :latn}

iex> Cldr.Number.System.system_name_from(:nope, "en", TestBackend.Cldr)
{
  :error,
  {Cldr.UnknownNumberSystemError, "The number system :nope is unknown"}
}

Note that return value is not guaranteed to be a valid number system for the given locale as demonstrated in the third example.

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system_name_from!(system_name, locale, backend)

View Source 
@spec system_name_from!(system_name(), Cldr.Locale.locale_reference(), Cldr.backend()) ::
  atom() | no_return()

Returns a number system name for a given locale and number system reference or raises an exception.

Arguments

Returns

  • number_system_name or

  • raises an exception.

Examples 

iex> Cldr.Number.System.system_name_from!(:default, "en", TestBackend.Cldr)
:latn

iex> Cldr.Number.System.system_name_from!("latn", "en", TestBackend.Cldr)
:latn

iex> Cldr.Number.System.system_name_from!(:traditional, "he", TestBackend.Cldr)
:hebr
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systems_with_digits()

View Source
This function is deprecated. Use numeric_systems/0 instead.

See Cldr.Number.System.numeric_systems/0.

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to_system(number, system_name, backend)

View Source 
@spec to_system(Cldr.Math.number_or_decimal(), atom(), Cldr.backend()) ::
  {:ok, binary()} | {:error, {module(), String.t()}}

Converts a number into the representation of a non-latin number system.

This function converts numbers to a known number system only, it does not provide number formatting.

Arguments

Returns

  • {:ok, string_of_digits} or

  • {:error, {exception, reason}}

Notes

There are two types of number systems in CLDR:

  • :numeric in which the number system defines a direct mapping between the latin digits 0..9 into a the number system equivalent. In this case, to_system/3 invokes Cldr.Number.Transliterate.transliterate_digits/3 for the given number.

  • :algorithmic in which the number system does not have the same structure as the :latn number system and therefore the conversion is done algorithmically. For CLDR the algorithm is implemented through Cldr.Rbnf rulesets. These rulesets are considered by CLDR to be less rigorous than the :numeric number systems and caution and testing for a specific use case is recommended.

Examples 

iex> Cldr.Number.System.to_system(123456, :hebr, TestBackend.Cldr)
{:ok, "ืงื›ืดื’ืณืชื ืดื•"}

iex> Cldr.Number.System.to_system(123, :hans, TestBackend.Cldr)
{:ok, "ไธ€็™พไบŒๅไธ‰"}

iex> Cldr.Number.System.to_system(123, :hant, TestBackend.Cldr)
{:ok, "ไธ€็™พไบŒๅไธ‰"}

iex> Cldr.Number.System.to_system(123, :hansfin, TestBackend.Cldr)
{:ok, "ๅฃนไฝฐ่ดฐๆ‹พๅ"}
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to_system!(number, system_name, backend)

View Source 
@spec to_system!(Cldr.Math.number_or_decimal(), atom(), Cldr.backend()) ::
  binary() | no_return()

Converts a number into the representation of a non-latin number system or raises an exception.

Arguments

Returns

  • string_of_digits or

  • raises an exception

See Cldr.Number.System.to_system/3 for further information.

Examples 

iex> Cldr.Number.System.to_system!(123, :hans, TestBackend.Cldr)
"ไธ€็™พไบŒๅไธ‰"

iex> Cldr.Number.System.to_system!(123, :hant, TestBackend.Cldr)
"ไธ€็™พไบŒๅไธ‰"

iex> Cldr.Number.System.to_system!(123, :hansfin, TestBackend.Cldr)
"ๅฃนไฝฐ่ดฐๆ‹พๅ"
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unknown_number_system_for_locale_error(number_system, locale, valid_number_systems)

View Source

Returns an error tuple for an number system unknown to a given locale.

Arguments

Returns

  • {Cldr.UnknownNumberSystemError, reason}