IntlMemoizer

The fluent-rs workspace is a collection of Rust crates implementing Project Fluent, a localization system designed to unleash the entire expressive power of natural language translations.

This crate is a memoizer specifically tailored for storing lazy-initialized intl formatters.

Usage

The assumption is that allocating a new formatter instance is costly, and such instance is read-only during its life time, with constructor being expensive, and format/select calls being cheap.

In result it pays off to use a singleton to manage memoization of all instances of intl APIs such as PluralRules, DateTimeFormat etc. between all FluentBundle instances.

The following is a high-level example of how this works, for running examples see the docs

/// Internationalization formatter should implement the Memoizable trait.
impl Memoizable for NumberFormat {
  ...
}

// The main memoizer has weak references to all of the per-language memoizers.
let mut memoizer = IntlMemoizer::default();

// The formatter memoziation happens per-locale.
let lang = "en-US".parse().expect("Failed to parse.");
let lang_memoizer: Rc<IntlLangMemoizer> = memoizer.get_for_lang(en_us);

// Run the formatter

let options: NumberFormatOptions {
    minimum_fraction_digits: 3,
    maximum_fraction_digits: 5,
};

// Format pi with the options. This will lazily construct the NumberFormat.
let pi = lang_memoizer
    .with_try_get::<NumberFormat, _, _>((options,), |nf| nf.format(3.141592653))
    .unwrap()

// The example formatter constructs a string with diagnostic information about
// the configuration.
assert_eq!(text, "3.14159");

// Running it again will use the previous formatter.
let two = lang_memoizer
    .with_try_get::<NumberFormat, _, _>((options,), |nf| nf.format(2.0))
    .unwrap()

assert_eq!(text, "2.000");

Get Involved

fluent-rs is open-source, licensed under both the Apache 2.0 and MIT licenses. We encourage everyone to take a look at our code and we'll listen to your feedback.

Discuss

We'd love to hear your thoughts on Project Fluent! Whether you're a localizer looking for a better way to express yourself in your language, or a developer trying to make your app localizable and multilingual, or a hacker looking for a project to contribute to, please do get in touch on the mailing list and the IRC channel.

• Discourse: https://discourse.mozilla.org/c/fluent
• Matrix channel: #fluent:mozilla.org