v1::language_tag Class Reference

#include <hikogui/i18n/language_tag.hpp>

Public Member Functions
constexpr	language_tag (language_tag const &) noexcept=default
constexpr	language_tag (language_tag &&) noexcept=default
constexpr language_tag &	operator= (language_tag const &) noexcept=default
constexpr language_tag &	operator= (language_tag &&) noexcept=default
constexpr	language_tag (iso_639 const &language, iso_15924 const &script={}, iso_3166 const &region={}) noexcept
constexpr	language_tag (iso_639 const &language, iso_3166 const &region) noexcept
	language_tag (std::string_view str)
	Parse a language tag.
bool	empty () const noexcept
	Check if the language tag is empty.
	operator bool () const noexcept
	Check if the language tag is used.
generator< language_tag >	variants () const noexcept
	Get variants of the language_tag.
generator< language_tag >	canonical_variants () const noexcept
	Get variants of the language_tag.
std::vector< language_tag >	all_variants () const noexcept
	Creates variants of a language tag, including those by expanding the normal variants.
language_tag	expand () const noexcept
	Expand the language tag to include script and language.
language_tag	shrink () const noexcept
	Get a tag with only the language.
unicode_bidi_class	writing_direction () const noexcept
	The language direction for this language-tag.
std::string	to_string () const noexcept

Static Public Member Functions
static language_tag	parse (std::string_view str)
	Parse the language, script and region raw from the string.

Data Fields
iso_639	language
iso_15924	script
iso_3166	region
uint16_t	_reserved = 0

Friends
constexpr friend bool	match (language_tag const &lhs, language_tag const &rhs) noexcept
	Check if two language_tags match for their non-empty fields.
constexpr friend bool	operator== (language_tag const &, language_tag const &) noexcept=default

Detailed Description

The IETF BCP 47 language tag.

This class stores the language tag in 64 bits; in its individual components of the: ISO-639 language (16 bit), ISO-15924 script (16 bit) and ISO-3166 region (16 bit). In the future another 16 bits can be used to store the variants and extensions.

Constructor & Destructor Documentation

language_tag()

v1::language_tag::language_tag

(

std::string_view

str

)

Parse a language tag.

This will construct a language tag with the language, script and region set as complete as possible. It does this by expanding the language tags using default script, region and grandfathering tables.

This function will ignore upper/lower case of the sub-tags, and allow for both underscores '_' and dashes '-' to separate the sub-tags.

Parameters

str	The language tag to parse

Exceptions

parse_error

Member Function Documentation

all_variants()

std::vector< language_tag > v1::language_tag::all_variants ( ) const

inlinenoexcept

Creates variants of a language tag, including those by expanding the normal variants.

canonical_variants()

generator< language_tag > v1::language_tag::canonical_variants ( ) const

inlinenoexcept

Get variants of the language_tag.

This function will create language_tags that may include this tag and tags with strictly less information (no script, no region), which still canonically expands into this tag.

Returns

A list of language-tags sorted: lang-script-region, lang-region, lang-script, lang

empty()

bool v1::language_tag::empty ( ) const

inlinenoexcept

Check if the language tag is empty.

expand()

language_tag v1::language_tag::expand ( ) const

noexcept

Expand the language tag to include script and language.

Expansion is done by querying default script, default language and grandfathering tables.

operator bool()

v1::language_tag::operator bool ( ) const

inlineexplicitnoexcept

Check if the language tag is used.

parse()

static language_tag v1::language_tag::parse ( std::string_view str )

static

Parse the language, script and region raw from the string.

No automatic expansion of the script or region will be done.

shrink()

language_tag v1::language_tag::shrink ( ) const

inlinenoexcept

Get a tag with only the language.

variants()

generator< language_tag > v1::language_tag::variants ( ) const

inlinenoexcept

Get variants of the language_tag.

This function will create language_tags that includes this tag and tags with strictly less information (no script, no region).

Returns

A list of language-tags sorted: lang-script-region, lang-region, lang-script, lang

writing_direction()

unicode_bidi_class v1::language_tag::writing_direction ( ) const

inlinenoexcept

The language direction for this language-tag.

Returns

Either unicode_bidi_class::L for left-to-right; or unicode_bidi_class::R for right-to-left

Friends And Related Symbol Documentation

match

constexpr friend bool match ( language_tag const & lhs, language_tag const & rhs )

friend

Check if two language_tags match for their non-empty fields.

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The documentation for this class was generated from the following file:

• hikogui/src/hikogui/i18n/language_tag.hpp