Lingua I18n for Rust

A simple and lightweight internationalization (i18n) library for Rust applications.

Features

• Easy to set up and use
• JSON-based translations
• Nested keys support with dot notation
• Variable substitution with {{variable}} syntax
• Automatic language detection from system settings
• Minimal dependencies

Installation

Add this to your Cargo.toml:

[dependencies]
lingua-i18n-rs = "0.3.0"

Quick Start

use lingua_i18n_rs::prelude::*;

fn main() -> Result<(), LinguaError> {
    // Initialize with language files in the "languages" directory
    Lingua::new("languages").init()?;

    // Get a simple translation
    println!("{}", Lingua::t("welcome", &[])?);

    // With parameter substitution
    println!("{}", Lingua::t("greeting", &[("name", "World")])?);

    // Using nested keys
    println!("{}", Lingua::t("menu.file.save", &[])?);

    // List available languages
    let languages = Lingua::get_languages()?;
    println!("Available languages: {:?}", languages);

    // Change language
    if Lingua::set_language("fr")? {
        println!("Language changed to French");
    }

    Ok(())
}

Language Files

Place your translation files in a directory (default: "languages"). Each file should be named with its language code and have a .json extension:

languages/en.json:

{
  "welcome": "Welcome to the application!",
  "greeting": "Hello, {{name}}!",
  "menu": {
    "file": {
      "save": "Save"
    }
  }
}

languages/de.json:

{
  "welcome": "Willkommen in der Anwendung!",
  "greeting": "Hallo, {{name}}!",
  "menu": {
    "file": {
      "save": "Speichern"
    }
  }
}

API Reference

Lingua::new(language_dir: &str) -> LinguaBuilder

Create a new builder with a custom language directory.

LinguaBuilder::init() -> Result<Lingua, LinguaError>

Initialize the library and load all available languages from the specified directory.

Lingua::t(key: &str, params: &[(&str, &str)]) -> Result<String, LinguaError>

Translate a key with optional parameters. Short form of translate.

Lingua::translate(key: &str, params: &[(&str, &str)]) -> Result<String, LinguaError>

Translate a key with optional parameters.

Lingua::set_language(lang_code: &str) -> Result<bool, LinguaError>

Change the current language. Returns Ok(true) if successful, or an error if the language is not available.

Lingua::get_languages() -> Result<Vec<String>, LinguaError>

Get a list of all available languages.

Lingua::get_language() -> Result<String, LinguaError>

Get the current language code.

Lingua::load_lang_from_config(path: &Path, key: &str) -> Result<String, LinguaError>

Load a language code from a configuration file. If you are using a configuration file to store the language code, you can use this function to load it.

Examples

See the examples directory for more complete examples. To run an example, use the following command:

cargo run --example <example_name>

For an example using Lingua, see the rusty-weather

License

This project is licensed under the MIT License - see the LICENSE file for details.