| lib.rs |
Fluent is a modern localization system designed to improve how software is translated.
The Rust implementation provides the low level components for syntax operations, like parser
and AST, and the core localization struct - [`FluentBundle`].
[`FluentBundle`] is the low level container for storing and formatting localization messages
in a single locale.
This crate provides also a number of structures needed for a localization API such as [`FluentResource`],
[`FluentMessage`], [`FluentArgs`], and [`FluentValue`].
Together, they allow implementations to build higher-level APIs that use [`FluentBundle`]
and add user friendly helpers, framework bindings, error fallbacking,
language negotiation between user requested languages and available resources,
and I/O for loading selected resources.
# Example
```
use fluent::{FluentBundle, FluentValue, FluentResource, FluentArgs};
// Used to provide a locale for the bundle.
use unic_langid::LanguageIdentifier;
let ftl_string = String::from("
hello-world = Hello, world!
intro = Welcome, { $name }.
");
let res = FluentResource::try_new(ftl_string)
.expect("Failed to parse an FTL string.");
let langid_en: LanguageIdentifier = "en-US".parse().expect("Parsing failed");
let mut bundle = FluentBundle::new(vec![langid_en]);
bundle
.add_resource(res)
.expect("Failed to add FTL resources to the bundle.");
let msg = bundle.get_message("hello-world")
.expect("Message doesn't exist.");
let mut errors = vec![];
let pattern = msg.value()
.expect("Message has no value.");
let value = bundle.format_pattern(&pattern, None, &mut errors);
assert_eq!(&value, "Hello, world!");
let mut args = FluentArgs::new();
args.set("name", FluentValue::from("John"));
let msg = bundle.get_message("intro")
.expect("Message doesn't exist.");
let mut errors = vec![];
let pattern = msg.value().expect("Message has no value.");
let value = bundle.format_pattern(&pattern, Some(&args), &mut errors);
// The FSI/PDI isolation marks ensure that the direction of
// the text from the variable is not affected by the translation.
assert_eq!(value, "Welcome, \u{2068}John\u{2069}.");
```
# Ergonomics & Higher Level APIs
Reading the example, you may notice how verbose it feels.
Many core methods are fallible, others accumulate errors, and there
are intermediate structures used in operations.
This is intentional as it serves as building blocks for variety of different
scenarios allowing implementations to handle errors, cache and
optimize results.
At the moment it is expected that users will use
the `fluent-bundle` crate directly, while the ecosystem
matures and higher level APIs are being developed.
[`FluentBundle`]: ./struct.FluentBundle.html
[`FluentResource`]: ./struct.FluentResource.html
[`FluentMessage`]: ./struct.FluentMessage.html
[`FluentArgs`]: ./type.FluentArgs.html
[`FluentValue`]: ./struct.FluentValue.html |
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