Struct MyLanguageTag

pub struct MyLanguageTag(/* private fields */);

A wrapper around LanguageTag to use it when Option<T>, serialization and deserialization are needed.

Language tags are used to help identify languages, whether spoken, written, signed, or otherwise signaled, for the purpose of communication. This includes constructed and artificial languages but excludes languages not intended primarily for human communication, such as programming languages.

Implementations

impl MyLanguageTag

pub fn as_str(&self) -> &str

Return the language tag as a string reference.

Methods from Deref<Target = LanguageTag>

pub fn as_str(&self) -> &str

Return the serialization of this language tag.

This is fast since that serialization is already stored in the LanguageTag struct.

pub fn primary_language(&self) -> &str

Return the primary language subtag.

use language_tags::LanguageTag;

let language_tag = LanguageTag::parse("zh-cmn-Hans-CN").unwrap();
assert_eq!(language_tag.primary_language(), "zh");

pub fn extended_language(&self) -> Option<&str>

Return the extended language subtags.

Valid language tags have at most one extended language.

use language_tags::LanguageTag;

let language_tag = LanguageTag::parse("zh-cmn-Hans-CN").unwrap();
assert_eq!(language_tag.extended_language(), Some("cmn"));

pub fn extended_language_subtags(&self) -> impl Iterator<Item = &str>

Iterate on the extended language subtags.

Valid language tags have at most one extended language.

use language_tags::LanguageTag;

let language_tag = LanguageTag::parse("zh-cmn-Hans-CN").unwrap();
assert_eq!(language_tag.extended_language_subtags().collect::<Vec<_>>(), vec!["cmn"]);

pub fn full_language(&self) -> &str

Return the primary language subtag and its extended language subtags.

use language_tags::LanguageTag;

let language_tag = LanguageTag::parse("zh-cmn-Hans-CN").unwrap();
assert_eq!(language_tag.full_language(), "zh-cmn");

pub fn script(&self) -> Option<&str>

Return the script subtag.

use language_tags::LanguageTag;

let language_tag = LanguageTag::parse("zh-cmn-Hans-CN").unwrap();
assert_eq!(language_tag.script(), Some("Hans"));

pub fn region(&self) -> Option<&str>

Return the region subtag.

use language_tags::LanguageTag;

let language_tag = LanguageTag::parse("zh-cmn-Hans-CN").unwrap();
assert_eq!(language_tag.region(), Some("CN"));

pub fn variant(&self) -> Option<&str>

Return the variant subtags.

use language_tags::LanguageTag;

let language_tag = LanguageTag::parse("zh-Latn-TW-pinyin").unwrap();
assert_eq!(language_tag.variant(), Some("pinyin"));

pub fn variant_subtags(&self) -> impl Iterator<Item = &str>

Iterate on the variant subtags.

use language_tags::LanguageTag;

let language_tag = LanguageTag::parse("zh-Latn-TW-pinyin").unwrap();
assert_eq!(language_tag.variant_subtags().collect::<Vec<_>>(), vec!["pinyin"]);

pub fn extension(&self) -> Option<&str>

Return the extension subtags.

use language_tags::LanguageTag;

let language_tag = LanguageTag::parse("de-DE-u-co-phonebk").unwrap();
assert_eq!(language_tag.extension(), Some("u-co-phonebk"));

pub fn extension_subtags(&self) -> impl Iterator<Item = (char, &str)>

Iterate on the extension subtags.

use language_tags::LanguageTag;

let language_tag = LanguageTag::parse("de-DE-u-co-phonebk").unwrap();
assert_eq!(language_tag.extension_subtags().collect::<Vec<_>>(), vec![('u', "co-phonebk")]);

pub fn private_use(&self) -> Option<&str>

Return the private use subtags.

use language_tags::LanguageTag;

let language_tag = LanguageTag::parse("de-x-foo-bar").unwrap();
assert_eq!(language_tag.private_use(), Some("x-foo-bar"));

pub fn private_use_subtags(&self) -> impl Iterator<Item = &str>

Iterate on the private use subtags.

use language_tags::LanguageTag;

let language_tag = LanguageTag::parse("de-x-foo-bar").unwrap();
assert_eq!(language_tag.private_use_subtags().collect::<Vec<_>>(), vec!["foo", "bar"]);

pub fn validate(&self) -> Result<(), ValidationError>

Check if the language tag is “valid” according to RFC 5646.

It applies the following steps:

• grandfathereds and private use tags are valid
• There should be no more than one extended language subtag (c.f. errata 5457).
• Primary language, extended language, script, region and variants should appear in the IANA Language Subtag Registry.
• Extended language and variants should have a correct prefix as set in the IANA Language Subtag Registry.
• There should be no duplicate variant and singleton (extension) subtags.

Errors

If the language tag is not “valid” a ValidationError variant will be returned.

pub fn is_valid(&self) -> bool

Check if the language tag is valid according to RFC 5646.

pub fn canonicalize(&self) -> Result<LanguageTag, ValidationError>

Returns the canonical version of the language tag following RFC 5646 4.5.

It currently applies the following steps:

• Grandfathered tags are replaced with the canonical version if possible.
• Redundant tags are replaced with the canonical version if possible.
• Extension languages are promoted to primary language.
• Deprecated languages, scripts, regions and variants are replaced with modern equivalents.
• Suppress-Script is applied to remove default script for a language (e.g. “en-Latn” is canonicalized as “en”).
• Variants are deduplicated

Errors

If there is not a unique way to canonicalize the language tag a ValidationError variant will be returned.

pub fn matches(&self, other: &LanguageTag) -> bool

Matches language tags. The first language acts as a language range, the second one is used as a normal language tag. None fields in the language range are ignored. If the language tag has more extlangs than the range these extlangs are ignored. Matches are case-insensitive.

For example the range en-GB matches only en-GB and en-Arab-GB but not en. The range en matches all language tags starting with en including en, en-GB, en-Arab and en-Arab-GB.

Panics

If the language range has extensions or private use tags.

Examples

use language_tags::LanguageTag;

let range_italian = LanguageTag::parse("it").unwrap();
let tag_german = LanguageTag::parse("de").unwrap();
let tag_italian_switzerland = LanguageTag::parse("it-CH").unwrap();
assert!(!range_italian.matches(&tag_german));
assert!(range_italian.matches(&tag_italian_switzerland));

let range_spanish_brazil = LanguageTag::parse("es-BR").unwrap();
let tag_spanish = LanguageTag::parse("es").unwrap();
assert!(!range_spanish_brazil.matches(&tag_spanish));

pub fn is_language_range(&self) -> bool

Checks if it is a language range, meaning that there are no extension and privateuse tags.

Trait Implementations

impl Clone for MyLanguageTag

fn clone(&self) -> MyLanguageTag

Returns a duplicate of the value.

const fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for MyLanguageTag

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Deref for MyLanguageTag

type Target = LanguageTag

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl DerefMut for MyLanguageTag

fn deref_mut(&mut self) -> &mut Self::Target

Mutably dereferences the value.

impl<'de> Deserialize<'de> for MyLanguageTag

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Display for MyLanguageTag

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl From<LanguageTag> for MyLanguageTag

fn from(value: LanguageTag) -> Self

Converts to this type from the input type.

impl FromStr for MyLanguageTag

type Err = DataError

The associated error which can be returned from parsing.

fn from_str(s: &str) -> Result<Self, Self::Err>

Parses a string s to return a value of this type.

impl Ord for MyLanguageTag

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq<MyLanguageTag> for &MyLanguageTag

fn eq(&self, other: &MyLanguageTag) -> bool

Tests for self and other values to be equal, and is used by ==.

const fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialEq<String> for MyLanguageTag

fn eq(&self, other: &String) -> bool

Tests for self and other values to be equal, and is used by ==.

const fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialEq<str> for MyLanguageTag

fn eq(&self, other: &str) -> bool

Tests for self and other values to be equal, and is used by ==.

const fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialEq for MyLanguageTag

fn eq(&self, other: &MyLanguageTag) -> bool

Tests for self and other values to be equal, and is used by ==.

const fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for MyLanguageTag

fn partial_cmp(&self, other: &Self) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl Serialize for MyLanguageTag

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Eq for MyLanguageTag

impl StructuralPartialEq for MyLanguageTag