View Source Expo.PluralForms (expo v1.1.0)

Functions to parse and evaluate plural forms as defined in the GNU Gettext documentation.

The documentation is available at https://www.gnu.org/software/gettext/manual/html_node/Plural-forms.html.

Usage

Some functions in this module are considered "low level", and are meant to be used by other libraries. For example, parse/1 returns an expression that is not really meant to be inspected, but rather used internally by this library.

Summary

Types

plural_ast()

The AST of a plural forms expression.

t()

A struct representing a plural forms expression.

Functions

index(plural_form, n)

Gets the plural form for the given number based on the given plural_forms struct.

known_locales()

Get known locales where plural form information is available.

parse(content)

Parses a plural forms string into a t/0 struct.

parse!(content)

Parses a plural forms string into a t/0 struct, raising if there are errors.

plural_form(iso_language_tag)

Gets the plural form for the given language based on built-in information.

to_string(plural_forms)

Converts a plural forms struct into its string representation.

Types

plural_ast()

@opaque plural_ast()

The AST of a plural forms expression.

This is evaluated internally to determine the plural form for a given number using index/2, and is not meant to be inspected directly.

t()

@type t() :: %Expo.PluralForms{nplurals: pos_integer(), plural: plural_ast()}

A struct representing a plural forms expression.

Functions

index(plural_form, n)

@spec index(t(), non_neg_integer()) :: non_neg_integer()

Gets the plural form for the given number based on the given plural_forms struct.

Examples

iex> {:ok, plural_form} = Expo.PluralForms.parse("nplurals=2; plural=n != 1;")
iex> Expo.PluralForms.index(plural_form, 4)
1
iex> Expo.PluralForms.index(plural_form, 1)
0

known_locales()

@spec known_locales() :: [String.t(), ...]

Get known locales where plural form information is available.

Examples

iex> "de" in Expo.PluralForms.known_locales()
true

iex> "invalid" in Expo.PluralForms.known_locales()
false

parse(content)

@spec parse(String.t()) :: {:ok, t()} | {:error, Expo.PluralForms.SyntaxError.t()}

Parses a plural forms string into a t/0 struct.

Returns {:ok, struct} if the string is valid, or {:error, error} if it isn't.

Examples

iex> Expo.PluralForms.parse("nplurals=2; plural=n != 1;")
{:ok, Expo.PluralForms.parse!("nplurals=2; plural=n != 1;")}

parse!(content)

@spec parse!(String.t()) :: t()

Parses a plural forms string into a t/0 struct, raising if there are errors.

Same as parse/1, but returns the plural forms struct directly if the parsing is successful, or raises an error otherwise.

The Inspect implementation for the Expo.PluralForms struct uses this function to display the plural forms expression, which is why the example below might look a bit weird.

Examples

iex> Expo.PluralForms.parse!("nplurals=2; plural=n != 1;")
Expo.PluralForms.parse!("nplurals=2; plural=n != 1;")

plural_form(iso_language_tag)

@spec plural_form(String.t()) :: {:ok, t()} | :error

Gets the plural form for the given language based on built-in information.

Examples

iex> Expo.PluralForms.plural_form("de")
{:ok, Expo.PluralForms.parse!("nplurals=2; plural=(n != 1);")}

iex> Expo.PluralForms.plural_form("invalid")
:error

to_string(plural_forms)

@spec to_string(t()) :: String.t()

Converts a plural forms struct into its string representation.

Examples

iex> plural_forms = Expo.PluralForms.parse!("nplurals=2; plural=n != 1;")
iex> Expo.PluralForms.to_string(plural_forms)
"nplurals=2; plural=n != 1;"