i18ncpp

Overview

i18ncpp provides a powerful and flexible solution for adding internationalization (i18n) capabilities to your C++ projects. It offers a wide range of features for translation, pluralization, number formatting, currency formatting, and date/time formatting.

This library is a C++ implementation of the smiti18n Lua library, providing similar functionality with a C++ interface.

Features

• Translation Management: Load and manage translations from JSON files
• Variable Interpolation: Insert dynamic values into translations
• Pluralization: Handle grammatically correct plural forms for different languages
• Locale Fallbacks: Automatically use fallback translations when a specific locale is not available
• Nested Keys: Support for structured translation hierarchies
• Variants: Choose translations based on contextual parameters
• Number Formatting: Format numbers with locale-specific separators
• Currency Formatting: Format monetary values with appropriate currency symbols
• Date/Time Formatting: Format dates and times according to locale preferences

Installation

Using CMake

# Clone the repository
git clone https://github.com/yourusername/i18ncpp.git

# Create a build directory
mkdir build && cd build

# Configure and build
cmake ..
cmake --build .

# Install (optional)
cmake --install .

Dependencies

• C++17 or higher
• nlohmann/json for JSON parsing

Basic Usage

#include <i18ncpp.h>
#include <iostream>

int main() {
    i18n::I18N i18n;
    
    // Load translations from a JSON file
    i18n.loadLocaleFromFile("en.json");
    i18n.loadLocaleFromFile("fr.json");
    
    // Set active locale
    i18n.setLocale("en");
    
    // Basic translation
    std::cout << i18n.tr("greeting") << std::endl; // Hello!
    
    // Translation with parameter
    std::cout << i18n.tr("welcome", "John") << std::endl; // Welcome, John!
    
    // Pluralization
    std::cout << i18n.trPlural("items", 1) << std::endl; // 1 item
    std::cout << i18n.trPlural("items", 5) << std::endl; // 5 items
    
    // Change locale
    i18n.setLocale("fr");
    std::cout << i18n.tr("greeting") << std::endl; // Bonjour!
    
    return 0;
}

Translation Files Format

Translation files use JSON format. Here's an example:

{
  "greeting": "Hello!",
  "welcome": "Welcome, {}!",
  "items": {
    "one": "{} item",
    "other": "{} items"
  },
  "user": {
    "login": "Log in",
    "logout": "Log out",
    "profile": "User profile"
  },
  "_formats": {
    "number": {
      "decimal_symbol": ".",
      "thousand_separator": ","
    },
    "currency": {
      "symbol": "$",
      "name": "US Dollar",
      "short_name": "USD"
    }
  }
}

API Reference

Core Methods

• loadLocale(locale, filePath): Load translations for a specific locale from a file
• loadLocaleFromFile(filePath): Load translations, extracting locale from filename
• setLocale(locale): Set the active locale
• setFallbackLocale(locale): Set the fallback locale
• getLocale(): Get the current active locale
• getFallbackLocale(): Get the current fallback locale

Translation Methods

• tr(key): Get a translation by key
• tr(key, param1): Get a translation with a single parameter
• tr(key, param1, param2, ...): Get a translation with multiple parameters
• tr(key, paramVector): Get a translation with a vector of parameters
• trv(key, ...args): Get a translation with variadic parameters
• trPlural(key, count): Get a pluralized translation
• trPlural(key, count, param1, ...): Get a pluralized translation with parameters
• trPluralv(key, count, ...args): Get a pluralized translation with variadic parameters

Formatting Methods

• formatNumber(number): Format a number according to locale settings
• formatPrice(amount): Format a monetary amount with currency symbol
• formatDate(pattern, date): Format a date/time value
• configure(formats): Configure formatting options

Advanced Usage

Pluralization Rules

The library supports pluralization rules for different languages, including:

• English-like languages (en, de, es, etc.)
• Slavic languages (ru, uk, pl, etc.)
• Arabic
• French
• Czech/Slovak
• And more

Interpolation Formats

Several interpolation formats are supported:

• {} or {0}, {1}, etc. for indexed parameters
• %{key} for named parameters
• %<key>.fmt for formatted parameters where fmt is a format specifier:
  • %<num>.d - integer format
  • %<num>.f - floating-point format
  • %<num>.s - string format

License

MIT License

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.