A simple math calculator built using Rust, compiled to WebAssembly, and executed in the browser with a clean HTML + JavaScript UI.
This project demonstrates how core Rust logic can be exposed to the web using wasm-bindgen, following real-world Rust → WASM best practices.
- Written in Rust
- Compiled to WebAssembly (WASM)
- Exposed to JavaScript using wasm-bindgen
- Interactive web-based UI
- Modular Rust code structure
- Safe error handling (e.g. division by zero)
- Addition
- Subtraction
- Multiplication
- Division (with error handling)
The following screenshots demonstrate the calculator running in the browser, with Rust logic executed via WebAssembly and results rendered on the UI.
rust_math_lib/
├── Cargo.toml
├── src/
│ ├── lib.rs # WASM entry point
│ ├── main.rs # CLI entry (optional)
│ └── math/
│ ├── mod.rs
│ └── operations.rs # Core math logic
├── pkg/ # Generated WASM output (wasm-pack)
│ ├── rust_math_lib.js
│ └── rust_math_lib_bg.wasm
├── index.html # Web UI
├── index.js # JS ↔ WASM bridge
├── screenshots/ # Demo screenshots
└── README.md
---
## Build Instructions
From the project root:
```bash
wasm-pack build --target web
This generates the WASM files inside the pkg/ directory.
python3 -m http.serverOpen in browser:
http://localhost:8000
You will see a web-based calculator powered entirely by Rust + WebAssembly.
The following Rust function is exposed to JavaScript:
#[wasm_bindgen]
pub fn calculate(operation: &str, a: f64, b: f64) -> Result<f64, String>calculate("add", 10, 5); // 15
calculate("divide", 10, 0); // Error: Division by zero- Rust module organization
- Difference between
lib.rsandmain.rs - Compiling Rust to WebAssembly
- JavaScript ↔ Rust interoperability
- Error handling across language boundaries