Struct icu_provider::DataKey

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pub struct DataKey { /* private fields */ }
Expand description

Used for loading data from an ICU4X data provider.

A resource key is tightly coupled with the code that uses it to load data at runtime. Executables can be searched for DataKey instances to produce optimized data files. Therefore, users should not generally create DataKey instances; they should instead use the ones exported by a component.

DataKeys are created with the data_key! macro:

const K: DataKey = icu_provider::data_key!("foo/bar@1");

The human-readable path string ends with @ followed by one or more digits (the version number). Paths do not contain characters other than ASCII letters and digits, _, /.

Invalid paths are compile-time errors (as data_key! uses const).

const K: DataKey = icu_provider::data_key!("foo/../bar@1");

Implementations§

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impl DataKey

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pub const fn path(self) -> DataKeyPath

Gets a human-readable representation of a DataKey.

The human-readable path string ends with @ followed by one or more digits (the version number). Paths do not contain characters other than ASCII letters and digits, _, /.

Useful for reading and writing data to a file system.

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pub const fn hashed(self) -> DataKeyHash

Gets a platform-independent hash of a DataKey.

The hash is 4 bytes and allows for fast key comparison.

§Example
use icu_provider::DataKey;
use icu_provider::DataKeyHash;

const KEY: DataKey = icu_provider::data_key!("foo@1");
const KEY_HASH: DataKeyHash = KEY.hashed();

assert_eq!(KEY_HASH.to_bytes(), [0xe2, 0xb6, 0x17, 0x71]);
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pub const fn metadata(self) -> DataKeyMetadata

Gets the metadata associated with this DataKey.

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pub const fn fallback_config(self) -> LocaleFallbackConfig

Returns the [LocaleFallbackConfig] for this DataKey.

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pub const fn from_path_and_metadata( path: DataKeyPath, metadata: DataKeyMetadata, ) -> Self

Constructs a DataKey from a path and metadata.

§Examples
use icu_provider::data_key;
use icu_provider::DataKey;

const CONST_KEY: DataKey = data_key!("foo@1");

let runtime_key =
    DataKey::from_path_and_metadata(CONST_KEY.path(), CONST_KEY.metadata());

assert_eq!(CONST_KEY, runtime_key);
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pub fn match_key(self, key: Self) -> Result<(), DataError>

Returns Ok if this data key matches the argument, or the appropriate error.

Convenience method for data providers that support a single DataKey.

§Examples
use icu_provider::prelude::*;

const FOO_BAR: DataKey = icu_provider::data_key!("foo/bar@1");
const FOO_BAZ: DataKey = icu_provider::data_key!("foo/baz@1");
const BAR_BAZ: DataKey = icu_provider::data_key!("bar/baz@1");

assert!(matches!(FOO_BAR.match_key(FOO_BAR), Ok(())));
assert!(matches!(
    FOO_BAR.match_key(FOO_BAZ),
    Err(DataError {
        kind: DataErrorKind::MissingDataKey,
        ..
    })
));
assert!(matches!(
    FOO_BAR.match_key(BAR_BAZ),
    Err(DataError {
        kind: DataErrorKind::MissingDataKey,
        ..
    })
));

// The error context contains the argument:
assert_eq!(FOO_BAR.match_key(BAR_BAZ).unwrap_err().key, Some(BAR_BAZ));

Trait Implementations§

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impl Clone for DataKey

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fn clone(&self) -> DataKey

Returns a copy of the value. Read more
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fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source. Read more
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impl Debug for DataKey

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

Formats the value using the given formatter. Read more
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impl Display for DataKey

This trait is implemented for compatibility with fmt!. To create a string, Writeable::write_to_string is usually more efficient.

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

Formats the value using the given formatter. Read more
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impl Hash for DataKey

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

Feeds this value into the given Hasher. Read more
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fn hash_slice<H>(data: &[Self], state: &mut H)
where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher. Read more
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impl Ord for DataKey

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

This method returns an Ordering between self and other. Read more
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fn max(self, other: Self) -> Self
where Self: Sized,

Compares and returns the maximum of two values. Read more
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fn min(self, other: Self) -> Self
where Self: Sized,

Compares and returns the minimum of two values. Read more
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fn clamp(self, min: Self, max: Self) -> Self
where Self: Sized + PartialOrd,

Restrict a value to a certain interval. Read more
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impl PartialEq for DataKey

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

Tests for self and other values to be equal, and is used by ==.
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fn ne(&self, other: &Rhs) -> bool

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

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

This method returns an ordering between self and other values if one exists. Read more
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fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator. Read more
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fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator. Read more
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fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator. Read more
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fn ge(&self, other: &Rhs) -> bool

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

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

Writes a string to the given sink. Errors from the sink are bubbled up. The default implementation delegates to write_to_parts, and discards any Part annotations.
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fn writeable_length_hint(&self) -> LengthHint

Returns a hint for the number of UTF-8 bytes that will be written to the sink. Read more
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fn write_to_string(&self) -> Cow<'_, str>

Creates a new String with the data from this Writeable. Like ToString, but smaller and faster. Read more
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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.
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fn writeable_cmp_bytes(&self, other: &[u8]) -> Ordering

Compares the contents of this Writeable to the given bytes without allocating a String to hold the Writeable contents. Read more
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impl Copy for DataKey

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impl Eq for DataKey

Auto Trait Implementations§

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impl<T> Any for T
where T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for T
where T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for T
where T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<T> CloneToUninit for T
where T: Clone,

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unsafe fn clone_to_uninit(&self, dst: *mut T)

🔬This is a nightly-only experimental API. (clone_to_uninit)
Performs copy-assignment from self to dst. Read more
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, U> Into<U> for T
where U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T> ToOwned for T
where T: Clone,

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type Owned = T

The resulting type after obtaining ownership.
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fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
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fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more
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impl<T> ToString for T
where T: Display + ?Sized,

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default fn to_string(&self) -> String

Converts the given value to a String. Read more
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impl<T, U> TryFrom<U> for T
where U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.
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impl<T> ErasedDestructor for T
where T: 'static,

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impl<T> MaybeSendSync for T