Functions for formatting numbers in a locale-aware manner.
This module provides the primary public API for converting numbers to localized string representations, including standard decimal formatting, currency formatting, percentage formatting, and scientific notation.
All formatting is driven by CLDR locale data accessed at runtime via the locale provider.
Summary
Functions
Parses a string to a number in a locale-aware manner.
Resolves currencies from strings within a list.
Resolves a currency from a string.
Resolves percent or permille from a string.
Resolves percent and permille symbols from strings within a list.
Scans a string and returns a list of strings and numbers.
Formats a number with the locale's approximately pattern.
Formats a number with the locale's "at least" pattern.
Formats a number with the locale's "at most" pattern.
Formats a numeric range as a localized string.
Same as to_range_string/3 but raises on error.
Formats a number as a rational fraction string.
Same as to_ratio_string/2 but raises on error.
Formats a number as a localized string.
Same as to_string/2 but raises on error.
Functions
Parses a string to a number in a locale-aware manner.
Delegates to Localize.Number.Parser.parse/2.
Arguments
stringis any string.optionsis a keyword list of options.
Returns
{:ok, number}or{:error, exception}.
Resolves currencies from strings within a list.
Delegates to Localize.Number.Parser.resolve_currencies/2.
Resolves a currency from a string.
Delegates to Localize.Number.Parser.resolve_currency/2.
Resolves percent or permille from a string.
Delegates to Localize.Number.Parser.resolve_per/2.
Resolves percent and permille symbols from strings within a list.
Delegates to Localize.Number.Parser.resolve_pers/2.
Scans a string and returns a list of strings and numbers.
Delegates to Localize.Number.Parser.scan/2.
Arguments
stringis any string.optionsis a keyword list of options.
Returns
- A list of strings and numbers.
@spec to_approximately_string(number() | Decimal.t(), Keyword.t()) :: {:ok, String.t()} | {:error, Exception.t()}
Formats a number with the locale's approximately pattern.
Produces strings like "~5" (English) or "約 5" (Japanese).
Arguments
numberis an integer, float, or Decimal.optionsis a keyword list of options accepted byto_string/2.
Returns
{:ok, formatted}on success.{:error, exception}if formatting fails.
Examples
iex> Localize.Number.to_approximately_string(5, locale: :en)
{:ok, "~5"}
@spec to_at_least_string(number() | Decimal.t(), Keyword.t()) :: {:ok, String.t()} | {:error, Exception.t()}
Formats a number with the locale's "at least" pattern.
Produces strings like "5+" (English) or "5以上" (Japanese).
Arguments
numberis an integer, float, or Decimal.optionsis a keyword list of options accepted byto_string/2.
Returns
{:ok, formatted}on success.{:error, exception}if formatting fails.
Examples
iex> Localize.Number.to_at_least_string(5, locale: :en)
{:ok, "5+"}
@spec to_at_most_string(number() | Decimal.t(), Keyword.t()) :: {:ok, String.t()} | {:error, Exception.t()}
Formats a number with the locale's "at most" pattern.
Produces strings like "≤5" (English) or "5以下" (Japanese).
Arguments
numberis an integer, float, or Decimal.optionsis a keyword list of options accepted byto_string/2.
Returns
{:ok, formatted}on success.{:error, exception}if formatting fails.
Examples
iex> Localize.Number.to_at_most_string(5, locale: :en)
{:ok, "≤5"}
@spec to_range_string(Range.t(), Keyword.t()) :: {:ok, String.t()} | {:error, Exception.t()}
Formats a numeric range as a localized string.
Accepts either two numbers or an Elixir Range. Uses the
locale's range pattern (e.g., "3–5" in English, "3~5" in
Japanese) to combine two formatted numbers. When the start and
end are equal, the locale's approximately pattern is used
instead (e.g., "~5").
Arguments
number_startis the start of the range (integer, float, or Decimal).number_endis the end of the range (integer, float, or Decimal).optionsis a keyword list of options.
Alternatively:
rangeis an ElixirRange.t/0(e.g.,3..5).optionsis a keyword list of options.
Options
All options accepted by to_string/2 are supported and applied
to both numbers. Additional options:
:approximateis a boolean. Whentrue, forces use of the approximately pattern regardless of whether start equals end. The default isfalse.
Returns
{:ok, formatted_range}on success.{:error, exception}if formatting fails.
Examples
iex> Localize.Number.to_range_string(3, 5, locale: :en)
{:ok, "3–5"}
iex> Localize.Number.to_range_string(3..5, locale: :en)
{:ok, "3–5"}
iex> Localize.Number.to_range_string(5, 5, locale: :en)
{:ok, "~5"}
Same as to_range_string/3 but raises on error.
Examples
iex> Localize.Number.to_range_string!(3, 5, locale: :en)
"3–5"
iex> Localize.Number.to_range_string!(3..5, locale: :en)
"3–5"
@spec to_ratio_string(number() | Decimal.t(), Keyword.t()) :: {:ok, String.t()} | {:error, Exception.t()}
Formats a number as a rational fraction string.
Converts a decimal number to its rational fraction representation using the continued fraction algorithm, then formats it with CLDR rational format patterns.
Arguments
numberis an integer, float, or Decimal.optionsis a keyword list of options.
Options
:localeis a locale identifier. The default isLocalize.get_locale().:preferis a list of rendering preferences. Valid values are:default,:super_sub, and:precomposed. The default is[:default].:max_denominatoris the largest permitted denominator. The default is10.:max_iterationsis the maximum continued fraction iterations. The default is20.:epsilonis the tolerance for float comparisons. The default is1.0e-10.
Returns
{:ok, formatted_string}on success.{:error, exception}if the number cannot be converted to a ratio or locale data is unavailable.
Examples
iex> Localize.Number.to_ratio_string(0.5)
{:ok, "1⁄2"}
iex> Localize.Number.to_ratio_string(0.5, prefer: [:precomposed])
{:ok, "½"}
iex> Localize.Number.to_ratio_string(0.5, prefer: [:super_sub])
{:ok, "¹⁄₂"}
iex> Localize.Number.to_ratio_string(1.5)
{:ok, "1 1⁄2"}
iex> Localize.Number.to_ratio_string(1.5, prefer: [:super_sub, :precomposed])
{:ok, "1½"}
Same as to_ratio_string/2 but raises on error.
Arguments
numberis an integer, float, or Decimal.optionsis a keyword list of options.
Returns
- The formatted ratio string.
Raises
- Raises an exception if the number cannot be converted.
@spec to_string(number() | Decimal.t(), Keyword.t() | struct()) :: {:ok, String.t()} | {:error, Exception.t()}
Formats a number as a localized string.
Arguments
numberis an integer, float, or Decimal.optionsis a keyword list of options.
Options
:localeis a locale identifier atom, string, or aLocalize.LanguageTag.t/0. The default is:en.:number_systemis a number system name or type atom. The default is:default.:formatis a format style atom or a format pattern string. The default is:standard. Common styles include:standard,:currency,:accounting,:percent,:scientific,:decimal_short,:decimal_long.:currencyis a currency code atom (e.g.,:USD). When provided, currency formatting is applied.:rounding_modeis one of:down,:half_up,:half_even,:ceiling,:floor,:half_down,:up. The default is:half_even.:fractional_digitsis an integer that sets both the minimum and maximum fractional digits to the same value. Equivalent to setting:min_fractional_digitsand:max_fractional_digitsto the same integer. Overridden by either of those options when they are also provided.:min_fractional_digitsis an integer specifying the minimum number of fractional digits. Trailing zeros are added to reach this count. When not set, falls back to:fractional_digitsor the format pattern default.:max_fractional_digitsis an integer specifying the maximum number of fractional digits. Values are rounded to fit. When not set, falls back to:fractional_digitsor the format pattern default.:maximum_integer_digitsis an integer specifying the maximum number of integer digits to display.:wrapperis a function of arity 2 that wraps formatted components. Useful for adding HTML markup.
Returns
{:ok, formatted_string}on success.{:error, exception}if options are invalid or formatting fails.
Examples
iex> Localize.Number.to_string(1234)
{:ok, "1,234"}
iex> Localize.Number.to_string(1234.5, locale: :en)
{:ok, "1,234.5"}
iex> Localize.Number.to_string(0.56, format: :percent, locale: :en)
{:ok, "56%"}
Same as to_string/2 but raises on error.
Arguments
numberis an integer, float, or Decimal.optionsis a keyword list of options.
Returns
- A formatted string.
Raises
- Raises an exception if formatting fails.
Examples
iex> Localize.Number.to_string!(1234)
"1,234"