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Diffstat (limited to 'third_party/rust/icu_provider/src/constructors.rs')
| -rw-r--r-- | third_party/rust/icu_provider/src/constructors.rs | 373 |
1 files changed, 373 insertions, 0 deletions
diff --git a/third_party/rust/icu_provider/src/constructors.rs b/third_party/rust/icu_provider/src/constructors.rs new file mode 100644 index 0000000000..f521f1feab --- /dev/null +++ b/third_party/rust/icu_provider/src/constructors.rs @@ -0,0 +1,373 @@ +// This file is part of ICU4X. For terms of use, please see the file +// called LICENSE at the top level of the ICU4X source tree +// (online at: https://github.com/unicode-org/icu4x/blob/main/LICENSE ). + +//! 📚 *This module documents ICU4X constructor signatures.* +//! +//! One of the key differences between ICU4X and its parent projects, ICU4C and ICU4J, is in how +//! it deals with locale data. +//! +//! In ICU4X, data can always be explicitly passed to any function that requires data. +//! This enables ICU4X to achieve the following value propositions: +//! +//! 1. Configurable data sources (machine-readable data file, baked into code, JSON, etc). +//! 2. Dynamic data loading at runtime (load data on demand). +//! 3. Reduced overhead and code size (data is resolved locally at each call site). +//! 4. Explicit support for multiple ICU4X instances sharing data. +//! +//! However, as manual data management can be tedious, ICU4X also has a `compiled_data` +//! default Cargo feature that includes data and makes ICU4X work out-of-the box. +//! +//! Subsequently, there are 4 versions of all Rust ICU4X functions that use data: +//! +//! 1. `*` +//! 2. `*_unstable` +//! 3. `*_with_any_provider` +//! 4. `*_with_buffer_provider` +//! +//! # Which constructor should I use? +//! +//! ## When to use `*` +//! +//! If you don't want to customize data at runtime (i.e. if you don't care about code size, +//! updating your data, etc.) you can use the `compiled_data` Cargo feature and don't have to think +//! about where your data comes from. +//! +//! These constructors are sometimes `const` functions, this way Rust can most effectively optimize +//! your usage of ICU4X. +//! +//! ## When to use `*_unstable` +//! +//! Use this constructor if your data provider implements the [`DataProvider`] trait for all +//! data structs in *current and future* ICU4X versions. Examples: +//! +//! 1. `BakedDataProvider` generated for the specific ICU4X minor version +//! 2. Anything with a _blanket_ [`DataProvider`] impl +//! +//! Since the exact set of bounds may change at any time, including in minor SemVer releases, +//! it is the client's responsibility to guarantee that the requirement is upheld. +//! +//! ## When to use `*_with_any_provider` +//! +//! Use this constructor if you need to use a provider that implements [`AnyProvider`] but not +//! [`DataProvider`]. Examples: +//! +//! 1. [`AnyPayloadProvider`] +//! 2. [`ForkByKeyProvider`] between two providers implementing [`AnyProvider`] +//! 3. Providers that cache or override certain keys but not others and therefore +//! can't implement [`DataProvider`] +//! +//! ## When to use `*_with_buffer_provider` +//! +//! Use this constructor if your data originates as byte buffers that need to be deserialized. +//! All such providers should implement [`BufferProvider`]. Examples: +//! +//! 1. [`BlobDataProvider`] +//! 2. [`FsDataProvider`] +//! 3. [`ForkByKeyProvider`] between two providers implementing [`BufferProvider`] +//! +//! Please note that you must enable the `serde` Cargo feature on each crate in which you use the +//! `*_with_buffer_provider` constructor. +//! +//! # Data Versioning Policy +//! +//! The `*_with_any_provider` and `*_with_buffer_provider` functions will succeed to compile and +//! run if given a data provider supporting all of the keys required for the object being +//! constructed, either the current or any previous version within the same SemVer major release. +//! For example, if a data file is built to support FooFormatter version 1.1, then FooFormatter +//! version 1.2 will be able to read the same data file. Likewise, backwards-compatible keys can +//! always be included by `icu_datagen` to support older library versions. +//! +//! The `*_unstable` functions are only guaranteed to work on data built for the exact same minor version +//! of ICU4X. The advantage of the `*_unstable` functions is that they result in the smallest code +//! size and allow for automatic data slicing when `BakedDataProvider` is used. However, the type +//! bounds of this function may change over time, breaking SemVer guarantees. These functions +//! should therefore only be used when you have full control over your data lifecycle at compile +//! time. +//! +//! # Data Providers Over FFI +//! +//! Over FFI, there is only one data provider type: [`ICU4XDataProvider`]. Internally, it is an +//! `enum` between`dyn `[`BufferProvider`] and a unit compiled data variant. +//! +//! To control for code size, there are two Cargo features, `compiled_data` and `buffer_provider`, +//! that enable the corresponding items in the enum. +//! +//! In Rust ICU4X, a similar enum approach was not taken because: +//! +//! 1. Feature-gating the enum branches gets complex across crates. +//! 2. Without feature gating, users need to carry Serde code even if they're not using it, +//! violating one of the core value propositions of ICU4X. +//! 3. We could reduce the number of constructors from 4 to 2 but not to 1, so the educational +//! benefit is limited. +//! +//! [`DataProvider`]: crate::DataProvider +//! [`BufferProvider`]: crate::BufferProvider +//! [`AnyProvider`]: crate::AnyProvider +//! [`AnyPayloadProvider`]: ../../icu_provider_adapters/any_payload/struct.AnyPayloadProvider.html +//! [`ForkByKeyProvider`]: ../../icu_provider_adapters/fork/struct.ForkByKeyProvider.html +//! [`BlobDataProvider`]: ../../icu_provider_blob/struct.BlobDataProvider.html +//! [`StaticDataProvider`]: ../../icu_provider_blob/struct.StaticDataProvider.html +//! [`FsDataProvider`]: ../../icu_provider_blob/struct.FsDataProvider.html +//! [`ICU4XDataProvider`]: ../../icu_capi/provider/ffi/struct.ICU4XDataProvider.html + +#[doc(hidden)] +#[macro_export] +macro_rules! gen_any_buffer_unstable_docs { + (ANY, $data:path) => { + concat!( + "A version of [`", stringify!($data), "`] that uses custom data ", + "provided by an [`AnyProvider`](icu_provider::AnyProvider).\n\n", + "[📚 Help choosing a constructor](icu_provider::constructors)", + ) + }; + (BUFFER, $data:path) => { + concat!( + "A version of [`", stringify!($data), "`] that uses custom data ", + "provided by a [`BufferProvider`](icu_provider::BufferProvider).\n\n", + "✨ *Enabled with the `serde` feature.*\n\n", + "[📚 Help choosing a constructor](icu_provider::constructors)", + ) + }; + (UNSTABLE, $data:path) => { + concat!( + "A version of [`", stringify!($data), "`] that uses custom data ", + "provided by a [`DataProvider`](icu_provider::DataProvider).\n\n", + "[📚 Help choosing a constructor](icu_provider::constructors)\n\n", + "<div class=\"stab unstable\">⚠️ The bounds on <tt>provider</tt> may change over time, including in SemVer minor releases.</div>" + ) + }; +} + +#[allow(clippy::crate_in_macro_def)] // by convention each crate's data provider is `crate::provider::Baked` +#[doc(hidden)] +#[macro_export] +macro_rules! gen_any_buffer_data_constructors { + (locale: skip, options: skip, error: $error_ty:path, $(#[$doc:meta])+) => { + $crate::gen_any_buffer_data_constructors!( + locale: skip, + options: skip, + error: $error_ty, + $(#[$doc])+ + functions: [ + try_new, + try_new_with_any_provider, + try_new_with_buffer_provider, + try_new_unstable, + Self, + ] + ); + }; + (locale: skip, options: skip, error: $error_ty:path, $(#[$doc:meta])+ functions: [$baked:ident, $any:ident, $buffer:ident, $unstable:ident $(, $struct:ident)? $(,)?]) => { + #[cfg(feature = "compiled_data")] + $(#[$doc])+ + pub fn $baked() -> Result<Self, $error_ty> { + $($struct :: )? $unstable(&crate::provider::Baked) + } + #[doc = $crate::gen_any_buffer_unstable_docs!(ANY, $($struct ::)? $baked)] + pub fn $any(provider: &(impl $crate::AnyProvider + ?Sized)) -> Result<Self, $error_ty> { + use $crate::AsDowncastingAnyProvider; + $($struct :: )? $unstable(&provider.as_downcasting()) + } + #[cfg(feature = "serde")] + #[doc = $crate::gen_any_buffer_unstable_docs!(BUFFER, $($struct ::)? $baked)] + pub fn $buffer(provider: &(impl $crate::BufferProvider + ?Sized)) -> Result<Self, $error_ty> { + use $crate::AsDeserializingBufferProvider; + $($struct :: )? $unstable(&provider.as_deserializing()) + } + }; + + + (locale: skip, options: skip, result: $result_ty:path, $(#[$doc:meta])+ functions: [$baked:ident, $any:ident, $buffer:ident, $unstable:ident $(, $struct:ident)? $(,)?]) => { + #[cfg(feature = "compiled_data")] + $(#[$doc])+ + pub fn $baked() -> $result_ty { + $($struct :: )? $unstable(&crate::provider::Baked) + } + #[doc = $crate::gen_any_buffer_unstable_docs!(ANY, $($struct ::)? $baked)] + pub fn $any(provider: &(impl $crate::AnyProvider + ?Sized)) -> $result_ty { + use $crate::AsDowncastingAnyProvider; + $($struct :: )? $unstable(&provider.as_downcasting()) + } + #[cfg(feature = "serde")] + #[doc = $crate::gen_any_buffer_unstable_docs!(BUFFER, $($struct ::)? $baked)] + pub fn $buffer(provider: &(impl $crate::BufferProvider + ?Sized)) -> $result_ty { + use $crate::AsDeserializingBufferProvider; + $($struct :: )? $unstable(&provider.as_deserializing()) + } + }; + + (locale: skip, $options_arg:ident: $options_ty:ty, error: $error_ty:path, $(#[$doc:meta])+) => { + $crate::gen_any_buffer_data_constructors!( + locale: skip, + $options_arg: $options_ty, + error: $error_ty, + $(#[$doc])+ + functions: [ + try_new, + try_new_with_any_provider, + try_new_with_buffer_provider, + try_new_unstable, + Self, + ] + ); + }; + (locale: skip, $options_arg:ident: $options_ty:ty, result: $result_ty:ty, $(#[$doc:meta])+ functions: [$baked:ident, $any:ident, $buffer:ident, $unstable:ident $(, $struct:ident)? $(,)?]) => { + #[cfg(feature = "compiled_data")] + $(#[$doc])+ + /// + /// ✨ *Enabled with the `compiled_data` Cargo feature.* + /// + /// [📚 Help choosing a constructor](icu_provider::constructors) + pub fn $baked($options_arg: $options_ty) -> $result_ty { + $($struct :: )? $unstable(&crate::provider::Baked, $options_arg) + } + #[doc = $crate::gen_any_buffer_unstable_docs!(ANY, $($struct ::)? $baked)] + pub fn $any(provider: &(impl $crate::AnyProvider + ?Sized), $options_arg: $options_ty) -> $result_ty { + use $crate::AsDowncastingAnyProvider; + $($struct :: )? $unstable(&provider.as_downcasting(), $options_arg) + } + #[cfg(feature = "serde")] + #[doc = $crate::gen_any_buffer_unstable_docs!(BUFFER, $($struct ::)? $baked)] + pub fn $buffer(provider: &(impl $crate::BufferProvider + ?Sized), $options_arg: $options_ty) -> $result_ty { + use $crate::AsDeserializingBufferProvider; + $($struct :: )? $unstable(&provider.as_deserializing(), $options_arg) + } + }; + (locale: skip, $options_arg:ident: $options_ty:ty, error: $error_ty:ty, $(#[$doc:meta])+ functions: [$baked:ident, $any:ident, $buffer:ident, $unstable:ident $(, $struct:ident)? $(,)?]) => { + #[cfg(feature = "compiled_data")] + $(#[$doc])+ + /// + /// ✨ *Enabled with the `compiled_data` Cargo feature.* + /// + /// [📚 Help choosing a constructor](icu_provider::constructors) + pub fn $baked($options_arg: $options_ty) -> Result<Self, $error_ty> { + $($struct :: )? $unstable(&crate::provider::Baked, $options_arg) + } + #[doc = $crate::gen_any_buffer_unstable_docs!(ANY, $($struct ::)? $baked)] + pub fn $any(provider: &(impl $crate::AnyProvider + ?Sized), $options_arg: $options_ty) -> Result<Self, $error_ty> { + use $crate::AsDowncastingAnyProvider; + $($struct :: )? $unstable(&provider.as_downcasting(), $options_arg) + } + #[cfg(feature = "serde")] + #[doc = $crate::gen_any_buffer_unstable_docs!(BUFFER, $($struct ::)? $baked)] + pub fn $buffer(provider: &(impl $crate::BufferProvider + ?Sized), $options_arg: $options_ty) -> Result<Self, $error_ty> { + use $crate::AsDeserializingBufferProvider; + $($struct :: )? $unstable(&provider.as_deserializing(), $options_arg) + } + }; + (locale: include, options: skip, error: $error_ty:path, $(#[$doc:meta])+) => { + $crate::gen_any_buffer_data_constructors!( + locale: include, + options: skip, + error: $error_ty, + $(#[$doc])+ + functions: [ + try_new, + try_new_with_any_provider, + try_new_with_buffer_provider, + try_new_unstable, + Self, + ] + ); + }; + (locale: include, options: skip, error: $error_ty:path, $(#[$doc:meta])+ functions: [$baked:ident, $any:ident, $buffer:ident, $unstable:ident $(, $struct:ident)? $(,)?]) => { + #[cfg(feature = "compiled_data")] + $(#[$doc])+ + /// + /// ✨ *Enabled with the `compiled_data` Cargo feature.* + /// + /// [📚 Help choosing a constructor](icu_provider::constructors) + pub fn $baked(locale: &$crate::DataLocale) -> Result<Self, $error_ty> { + $($struct :: )? $unstable(&crate::provider::Baked, locale) + } + #[doc = $crate::gen_any_buffer_unstable_docs!(ANY, $($struct ::)? $baked)] + pub fn $any(provider: &(impl $crate::AnyProvider + ?Sized), locale: &$crate::DataLocale) -> Result<Self, $error_ty> { + use $crate::AsDowncastingAnyProvider; + $($struct :: )? $unstable(&provider.as_downcasting(), locale) + } + #[cfg(feature = "serde")] + #[doc = $crate::gen_any_buffer_unstable_docs!(BUFFER, $($struct ::)? $baked)] + pub fn $buffer(provider: &(impl $crate::BufferProvider + ?Sized), locale: &$crate::DataLocale) -> Result<Self, $error_ty> { + use $crate::AsDeserializingBufferProvider; + $($struct :: )? $unstable(&provider.as_deserializing(), locale) + } + }; + + (locale: include, $config_arg:ident: $config_ty:path, $options_arg:ident: $options_ty:path, error: $error_ty:path, $(#[$doc:meta])+) => { + $crate::gen_any_buffer_data_constructors!( + locale: include, + $config_arg: $config_ty, + $options_arg: $options_ty, + error: $error_ty, + $(#[$doc])+ + functions: [ + try_new, + try_new_with_any_provider, + try_new_with_buffer_provider, + try_new_unstable, + Self, + ] + ); + }; + (locale: include, $config_arg:ident: $config_ty:path, $options_arg:ident: $options_ty:path, error: $error_ty:path, $(#[$doc:meta])+ functions: [$baked:ident, $any:ident, $buffer:ident, $unstable:ident $(, $struct:ident)? $(,)?]) => { + #[cfg(feature = "compiled_data")] + $(#[$doc])+ + /// + /// ✨ *Enabled with the `compiled_data` Cargo feature.* + /// + /// [📚 Help choosing a constructor](icu_provider::constructors) + pub fn $baked(locale: &$crate::DataLocale, $config_arg: $config_ty, $options_arg: $options_ty) -> Result<Self, $error_ty> { + $($struct :: )? $unstable(&crate::provider::Baked, locale, $config_arg, $options_arg) + } + #[doc = $crate::gen_any_buffer_unstable_docs!(ANY, $($struct ::)? $baked)] + pub fn $any(provider: &(impl $crate::AnyProvider + ?Sized), locale: &$crate::DataLocale, $config_arg: $config_ty, $options_arg: $options_ty) -> Result<Self, $error_ty> { + use $crate::AsDowncastingAnyProvider; + $($struct :: )? $unstable(&provider.as_downcasting(), locale, $config_arg, $options_arg) + } + #[cfg(feature = "serde")] + #[doc = $crate::gen_any_buffer_unstable_docs!(BUFFER, $($struct ::)? $baked)] + pub fn $buffer(provider: &(impl $crate::BufferProvider + ?Sized), locale: &$crate::DataLocale, $config_arg: $config_ty, $options_arg: $options_ty) -> Result<Self, $error_ty> { + use $crate::AsDeserializingBufferProvider; + $($struct :: )? $unstable(&provider.as_deserializing(), locale, $config_arg, $options_arg) + } + }; + + (locale: include, $options_arg:ident: $options_ty:path, error: $error_ty:path, $(#[$doc:meta])+) => { + $crate::gen_any_buffer_data_constructors!( + locale: include, + $options_arg: $options_ty, + error: $error_ty, + $(#[$doc])+ + functions: [ + try_new, + try_new_with_any_provider, + try_new_with_buffer_provider, + try_new_unstable, + Self, + ] + ); + }; + (locale: include, $options_arg:ident: $options_ty:path, error: $error_ty:path, $(#[$doc:meta])+ functions: [$baked:ident, $any:ident, $buffer:ident, $unstable:ident $(, $struct:ident)? $(,)?]) => { + #[cfg(feature = "compiled_data")] + $(#[$doc])+ + /// + /// ✨ *Enabled with the `compiled_data` Cargo feature.* + /// + /// [📚 Help choosing a constructor](icu_provider::constructors) + pub fn $baked(locale: &$crate::DataLocale, $options_arg: $options_ty) -> Result<Self, $error_ty> { + $($struct :: )? $unstable(&crate::provider::Baked, locale, $options_arg) + } + #[doc = $crate::gen_any_buffer_unstable_docs!(ANY, $($struct ::)? $baked)] + pub fn $any(provider: &(impl $crate::AnyProvider + ?Sized), locale: &$crate::DataLocale, $options_arg: $options_ty) -> Result<Self, $error_ty> { + use $crate::AsDowncastingAnyProvider; + $($struct :: )? $unstable(&provider.as_downcasting(), locale, $options_arg) + } + #[cfg(feature = "serde")] + #[doc = $crate::gen_any_buffer_unstable_docs!(BUFFER, $($struct ::)? $baked)] + pub fn $buffer(provider: &(impl $crate::BufferProvider + ?Sized), locale: &$crate::DataLocale, $options_arg: $options_ty) -> Result<Self, $error_ty> { + use $crate::AsDeserializingBufferProvider; + $($struct :: )? $unstable(&provider.as_deserializing(), locale, $options_arg) + } + }; +} |