🧠 Smart Unit Converter

A context-aware, highly intuitive command-line unit converter written in Rust. It doesn't just calculate; it understands what you mean. Type naturally, use math expressions, and let the smart engine do the rest!

✨ Features

• 🧠 Context-Aware Parsing: No strict syntax required! It extracts the data it needs from your sentence.
  • Example: how many meters are in 5 kilometers
• 🧮 Built-in Math Engine: Calculate and convert at the same time using the evalexpr engine.
  • Example: distance 5+3 km m or speed 100/2 mph kmh
• 🔄 Auto-Conversion: Omit the target unit to see conversions to all other units in the category.
  • Example: 5 km converts to meters, cm, and mm simultaneously.
• 🤖 Smart Error Suggestions: Made a typo? The fuzzy matcher will suggest the correct unit.
  • Example: distance 5 kilo m → Invalid unit: 'kilo'. Did you mean 'kilometer'?
• 📐 Smart Number Formatting: Automatically adjusts decimal precision for tiny numbers (e.g., 0.00001 km) and large numbers.
• ⏳ Persistent History: Use Up/Down arrows to navigate command history (powered by rustyline). History survives app restarts!
• ⚡ Dual Mode: Use it interactively (REPL) or directly from the command line (CLI) via clap.

📚 Supported Categories & Units

🚀 Getting Started

Prerequisites

You need to have Rust and Cargo installed on your system. If you don't, install them via rustup.

Installation

1. Clone the repository:

   git clone https://github.com/BakrLabs/unit-converter.git
   cd unit-converter
   

2. Build the project (Release mode for best performance):

   cargo build --release
   

3. Run the executable:

   ./target/release/unit-converter
   

💻 Usage

Interactive Mode (REPL)

Run the app and start typing naturally:

 $ unit-converter
=== Smart Unit Converter ===
Type 'help' for examples | Type 'exit' to quit

> speed 72 kmh to ms
72 km/h → 20 m/s

> how many meters are in 5 kilometers
5 km → 5000 m

> convert 100 c to f
100 °C → 212 °F

> distance 5+3 km m
8 km → 8000 m

> 50 mph kmh
50 mph → 80.4672 km/h

> 1 cm km
1 cm → 0.00001 km

CLI Mode (One-liner)

You can also use it directly from the terminal without entering the REPL:

 $ unit-converter speed 72 kmh ms
72 km/h → 20 m/s

 $ unit-converter distance 10 km
10 km → 10000 m
10 km → 1000000 cm
10 km → 10000000 mm

🛠️ Architecture & Tech Stack

This project isn't just a script; it's built with software engineering best practices in mind:

• Traits for DRY Code: The LinearUnit trait abstracts the conversion logic (to_base & convert_from_base). Adding a new category requires adding just one file and implementing the trait—no need to touch the core logic.
• Robust Error Handling: Uses the thiserror crate to define custom, user-friendly AppError types instead of panicking or using unwrap().
• Regex Entity Extraction: The parser uses regex to decouple numbers from units (e.g., parsing 5km into 5 and km), allowing flexible sentence structures.
• Math Evaluation: Integrates evalexpr safely, handling both Integer and Float returns seamlessly.
• Linting: Passes cargo clippy with zero warnings.

Crates Used

• clap - CLI argument parsing
• rustyline - Readline implementation for history/navigation
• regex - Context-aware string parsing
• evalexpr - Math expression evaluation
• thiserror - Error handling derivation
• colored - Terminal color output

🤝 Contributing

Contributions, issues, and feature requests are welcome! Feel free to check the issues page.

1. Fork the project
2. Create your feature branch (git checkout -b feature/NewCategory)
3. Commit your changes (git commit -m 'Add NewCategory')
4. Push to the branch (git push origin feature/NewCategory)
5. Open a Pull Request

📝 License

This project is Apache 2.0 licensed.