intl-memoizer is a crate designed to handle lazy-initialized references to intl formatters.
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, DateTimeFormatetc. between allFluentBundle` 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");
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.
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.