Struct icu_locid::LanguageIdentifier

pub struct LanguageIdentifier {
    pub language: Language,
    pub script: Option<Script>,
    pub region: Option<Region>,
    pub variants: Variants,
}

A core struct representing a Unicode BCP47 Language Identifier.

Examples

use icu::locid::{LanguageIdentifier, subtags::*};

let li: LanguageIdentifier = "en-US".parse().expect("Failed to parse.");

assert_eq!(li.language, "en".parse::<Language>().unwrap());
assert_eq!(li.script, None);
assert_eq!(li.region.unwrap(), "US".parse::<Region>().unwrap());
assert_eq!(li.variants.len(), 0);
assert_eq!(li.to_string(), "en-US");

Parsing

Unicode recognizes three levels of standard conformance for any language identifier:

• well-formed - syntactically correct
• valid - well-formed and only uses registered language, region, script and variant subtags…
• canonical - valid and no deprecated codes or structure.

At the moment parsing normalizes a well-formed language identifier converting _ separators to - and adjusting casing to conform to the Unicode standard.

Any bogus subtags will cause the parsing to fail with an error. No subtag validation is performed.

Examples

use icu::locid::{LanguageIdentifier, subtags::*};

let li: LanguageIdentifier = "eN_latn_Us-Valencia".parse().expect("Failed to parse.");

assert_eq!(li.language, "en".parse::<Language>().unwrap());
assert_eq!(li.script, "Latn".parse::<Script>().ok());
assert_eq!(li.region, "US".parse::<Region>().ok());
assert_eq!(li.variants.get(0), "valencia".parse::<Variant>().ok().as_ref());

Fields

language: Language

Language subtag of the language identifier.

script: Option<Script>

Script subtag of the language identifier.

region: Option<Region>

Region subtag of the language identifier.

variants: Variants

Variant subtags of the language identifier.

Implementations

impl LanguageIdentifier

pub fn from_bytes(v: &[u8]) -> Result<Self, ParserError>

A constructor which takes a utf8 slice, parses it and produces a well-formed LanguageIdentifier.

Examples

use icu::locid::LanguageIdentifier;

let li = LanguageIdentifier::from_bytes(b"en-US").expect("Parsing failed.");

assert_eq!(li.to_string(), "en-US");

pub fn from_locale_bytes(v: &[u8]) -> Result<Self, ParserError>

A constructor which takes a utf8 slice which may contain extension keys, parses it and produces a well-formed LanguageIdentifier.

Examples

use icu::locid::LanguageIdentifier;

let li = LanguageIdentifier::from_locale_bytes(b"en-US-x-posix").expect("Parsing failed.");

assert_eq!(li.to_string(), "en-US");

This method should be used for input that may be a locale identifier. All extensions will be lost.

pub const UND: Self = _

The default undefined language “und”. Same as default().

Examples

use icu::locid::LanguageIdentifier;

assert_eq!(LanguageIdentifier::default(), LanguageIdentifier::UND);
assert_eq!("und", LanguageIdentifier::UND.to_string());

pub fn canonicalize<S: AsRef<[u8]>>(input: S) -> Result<String, ParserError>

This is a best-effort operation that performs all available levels of canonicalization.

At the moment the operation will normalize casing and the separator, but in the future it may also validate and update from deprecated subtags to canonical ones.

Examples

use icu::locid::LanguageIdentifier;

assert_eq!(
    LanguageIdentifier::canonicalize("pL_latn_pl"),
    Ok("pl-Latn-PL".to_string())
);

pub fn strict_cmp(&self, other: &[u8]) -> Ordering

Compare this LanguageIdentifier with BCP-47 bytes.

The return value is equivalent to what would happen if you first converted this LanguageIdentifier to a BCP-47 string and then performed a byte comparison.

This function is case-sensitive and results in a total order, so it is appropriate for binary search. The only argument producing Ordering::Equal is self.to_string().

Examples

use icu::locid::LanguageIdentifier;
use std::cmp::Ordering;

let bcp47_strings: &[&str] = &[
    "pl-Latn-PL",
    "und",
    "und-Adlm",
    "und-GB",
    "und-ZA",
    "und-fonipa",
    "zh",
];

for ab in bcp47_strings.windows(2) {
    let a = ab[0];
    let b = ab[1];
    assert!(a.cmp(b) == Ordering::Less);
    let a_langid = a.parse::<LanguageIdentifier>().unwrap();
    assert_eq!(a, a_langid.to_string());
    assert!(a_langid.strict_cmp(a.as_bytes()) == Ordering::Equal);
    assert!(a_langid.strict_cmp(b.as_bytes()) == Ordering::Less);
}

pub fn strict_cmp_iter<'l, I>(&self, subtags: I) -> SubtagOrderingResult<I> where
    I: Iterator<Item = &'l [u8]>, 

Compare this LanguageIdentifier with an iterator of BCP-47 subtags.

This function has the same equality semantics as LanguageIdentifier::strict_cmp. It is intended as a more modular version that allows multiple subtag iterators to be chained together.

For an additional example, see SubtagOrderingResult.

Examples

use icu::locid::LanguageIdentifier;
use std::cmp::Ordering;

let subtags: &[&[u8]] = &[&*b"ca", &*b"ES", &*b"valencia"];

let loc = "ca-ES-valencia".parse::<LanguageIdentifier>().unwrap();
assert_eq!(
    Ordering::Equal,
    loc.strict_cmp_iter(subtags.iter().copied()).end()
);

let loc = "ca-ES".parse::<LanguageIdentifier>().unwrap();
assert_eq!(
    Ordering::Less,
    loc.strict_cmp_iter(subtags.iter().copied()).end()
);

let loc = "ca-ZA".parse::<LanguageIdentifier>().unwrap();
assert_eq!(
    Ordering::Greater,
    loc.strict_cmp_iter(subtags.iter().copied()).end()
);

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

Compare this LanguageIdentifier with a potentially unnormalized BCP-47 string.

The return value is equivalent to what would happen if you first parsed the BCP-47 string to a LanguageIdentifier and then performed a structucal comparison.

Examples

use icu::locid::LanguageIdentifier;
use std::cmp::Ordering;

let bcp47_strings: &[&str] = &[
    "pl-LaTn-pL",
    "uNd",
    "UnD-adlm",
    "uNd-GB",
    "UND-FONIPA",
    "ZH",
];

for a in bcp47_strings {
    assert!(a.parse::<LanguageIdentifier>().unwrap().normalizing_eq(a));
}

Trait Implementations

impl AsMut<LanguageIdentifier> for LanguageIdentifier

fn as_mut(&mut self) -> &mut Self

Converts this type into a mutable reference of the (usually inferred) input type.

impl AsMut<LanguageIdentifier> for Locale

fn as_mut(&mut self) -> &mut LanguageIdentifier

Converts this type into a mutable reference of the (usually inferred) input type.

impl AsRef<LanguageIdentifier> for LanguageIdentifier

fn as_ref(&self) -> &Self

Converts this type into a shared reference of the (usually inferred) input type.

impl AsRef<LanguageIdentifier> for Locale

fn as_ref(&self) -> &LanguageIdentifier

Converts this type into a shared reference of the (usually inferred) input type.

impl Clone for LanguageIdentifier

fn clone(&self) -> LanguageIdentifier

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for LanguageIdentifier

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

Formats the value using the given formatter.

impl Default for LanguageIdentifier

fn default() -> LanguageIdentifier

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for LanguageIdentifier

fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> where
    D: Deserializer<'de>, 

Deserialize this value from the given Serde deserializer.

impl Display for LanguageIdentifier

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

Formats the value using the given formatter.

impl From<&LanguageIdentifier> for (Language, Option<Script>, Option<Region>)

Convert from a LanguageIdentifier to an LSR tuple.

Examples

use icu::locid::LanguageIdentifier;
use icu::locid::{subtags_language as language, subtags_region as region, subtags_script as script, langid};

let lid = langid!("en-Latn-US");
let (lang, script, region) = (&lid).into();

assert_eq!(lang, language!("en"));
assert_eq!(script, Some(script!("Latn")));
assert_eq!(region, Some(region!("US")));

fn from(langid: &LanguageIdentifier) -> Self

Converts to this type from the input type.

impl From<(Language, Option<Script>, Option<Region>)> for LanguageIdentifier

Convert from an LSR tuple to a LanguageIdentifier.

Examples

use icu::locid::LanguageIdentifier;
use icu::locid::{subtags_language as language, subtags_region as region, subtags_script as script};

let lang = language!("en");
let script = script!("Latn");
let region = region!("US");
let li = LanguageIdentifier::from((lang, Some(script), Some(region)));

assert_eq!(li.language, lang);
assert_eq!(li.script.unwrap(), script);
assert_eq!(li.region.unwrap(), region);
assert_eq!(li.variants.len(), 0);
assert_eq!(li.to_string(), "en-Latn-US");

fn from(lsr: (Language, Option<Script>, Option<Region>)) -> Self

Converts to this type from the input type.

impl From<Language> for LanguageIdentifier

Examples

use icu::locid::subtags_language as language;
use icu::locid::LanguageIdentifier;

let language = language!("en");
let li = LanguageIdentifier::from(language);

assert_eq!(li.language, language);
assert_eq!(li.to_string(), "en");

fn from(language: Language) -> Self

Converts to this type from the input type.

impl From<LanguageIdentifier> for Locale

fn from(id: LanguageIdentifier) -> Self

Converts to this type from the input type.

impl From<Locale> for LanguageIdentifier

fn from(loc: Locale) -> Self

Converts to this type from the input type.

impl From<Option<Region>> for LanguageIdentifier

Examples

use icu::locid::subtags_region as region;
use icu::locid::LanguageIdentifier;

let region = region!("US");
let li = LanguageIdentifier::from(Some(region));

assert_eq!(li.region.unwrap(), region);
assert_eq!(li.to_string(), "und-US");

fn from(region: Option<Region>) -> Self

Converts to this type from the input type.

impl From<Option<Script>> for LanguageIdentifier

Examples

use icu::locid::subtags_script as script;
use icu::locid::LanguageIdentifier;

let script = script!("latn");
let li = LanguageIdentifier::from(Some(script));

assert_eq!(li.script.unwrap(), script);
assert_eq!(li.to_string(), "und-Latn");

fn from(script: Option<Script>) -> Self

Converts to this type from the input type.

impl FromStr for LanguageIdentifier

type Err = ParserError

The associated error which can be returned from parsing.

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

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

impl Hash for LanguageIdentifier

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given Hasher.

impl PartialEq<LanguageIdentifier> for LanguageIdentifier

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

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=.

impl Serialize for LanguageIdentifier

fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> where
    S: Serializer, 

Serialize this value into the given Serde serializer.

impl Writeable for LanguageIdentifier

fn write_to<W: Write + ?Sized>(&self, sink: &mut W) -> Result

Writes bytes to the given sink. Errors from the sink are bubbled up. The default implementation delegates to write_to_parts, and discards any Part annotations.

fn write_len(&self) -> LengthHint

Returns a hint for the number of bytes that will be written to the sink.

fn write_to_parts<S>(&self, sink: &mut S) -> Result<(), Error> where
    S: PartsWrite + ?Sized, 

Write bytes and Part annotations to the given sink. Errors from the sink are bubbled up. The default implementation delegates to write_to, and doesn’t produce any Part annotations.

fn write_to_string(&self) -> Cow<'_, str>

Creates a new String with the data from this Writeable. Like ToString, but smaller and faster.

impl Eq for LanguageIdentifier

impl StructuralEq for LanguageIdentifier

impl StructuralPartialEq for LanguageIdentifier