Crate icu_provider

icu_provider is one of the ICU4X components.

It defines traits and structs for transmitting data through the ICU4X locale data pipeline. The primary trait is DataProvider. It has one method, which transforms a Request into a Response:

fn load(&self, req: &DataRequest) -> Result<DataResponse<'d>, DataError>

A Request contains a DataKey (a composition of a Category and sub-category, e.g., "plurals/cardinal@1") and DataEntry (a language identifier and optional variant, e.g., "fr") being requested. The Response contains the data payload corresponding to the Request.

The most common types required for ICU4X DataProvider are included via the prelude:

use icu_provider::prelude::*;
use std::any::TypeId;

// Types included:
println!("{:?}", TypeId::of::<DataProvider>());
println!("{:?}", TypeId::of::<DataError>());
println!("{:?}", TypeId::of::<DataKey>());
println!("{:?}", TypeId::of::<DataEntry>());
println!("{:?}", TypeId::of::<DataCategory>());
println!("{:?}", TypeId::of::<DataRequest>());
println!("{:?}", TypeId::of::<DataResponse>());
println!("{:?}", TypeId::of::<DataResponseBuilder>());

// Macros included:
assert_eq!("plurals/cardinal@1", icu_data_key!(plurals: cardinal@1).to_string());

Types of Data Providers

Any object implementing DataProvider can be used to supply ICU4X with locale data. ICU4X ships with some pre-built data providers:

• FsDataProvider reads structured data from the filesystem. It can also write out that filesystem structure.
• CldrJsonDataProvider reads structured data directly from CLDR source files.

Iterable Data Providers

Data providers can implement DataEntryCollection, allowing them to be used via the auto-implemented trait IterableDataProvider. This allows iteration over all DataEntry instances supported for a certain key in the data provider. This can be useful when transforming data between storage formats. For more information, see the iter module.

InvariantDataProvider

For testing or development purposes, this crate also offers InvariantDataProvider, which returns fixed data that does not vary by locale. You must enable InvariantDataProvider via the "invariant" feature in your Cargo.toml file.

Re-exports

pub use prelude::*;

Modules

iter	Collection of iteration APIs for DataProvider.
prelude	Core selection of APIs and structures for DataProvider.
structs	Collection of data structures for DataProvider.

Macros

icu_data_key

Shortcut to construct a data key from a URI-like syntax.