Creating a complete Rust-based WebAssembly app to calculate the nth prime number involves several steps. First, you'll need to create the Rust code for the prime number calculation, then compile it to WebAssembly, and finally, create an HTML file that uses the compiled WebAssembly module.
Install Rust and its WebAssembly target:
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
rustup target add wasm32-unknown-unknown
Create a new Rust library:
cargo new --lib nth_prime_wasm
cd nth_prime_wasm
Add wasm-bindgen to your Cargo.toml:
[dependencies]
wasm-bindgen = "0.2"
[lib]
crate-type = ["cdylib"]
Replace the contents of src/lib.rs with the following Rust code:
use wasm_bindgen::prelude::*;
fn is_prime(n: u32) -> bool {
if n <= 1 {
return false;
}
for i in 2..n {
if n % i == 0 {
return false;
}
}
true
}
fn nth_prime(n: u32) -> u32 {
let mut count = 0;
let mut num = 0;
while count < n {
num += 1;
if is_prime(num) {
count += 1;
}
}
num
}
#[wasm_bindgen]
pub fn calculate_nth_prime(n: u32) -> u32 {
nth_prime(n)
}
Build the WebAssembly binary:
cargo install wasm-bindgen-cli
cargo build --target wasm32-unknown-unknown --release
wasm-bindgen --out-dir ./pkg --target web --no-typescript target/wasm32-unknown-unknown/release/nth_prime_wasm.wasm
Create an index.html file:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Nth Prime WebAssembly App</title>
</head>
<body>
<h1>Nth Prime WebAssembly App</h1>
<input type="number" id="input" placeholder="Enter a positive integer">
<button id="submit">Calculate Nth Prime</button>
<p id="result"></p>
<script type="module">
import init, { calculate_nth_prime } from './pkg/nth_prime_wasm.js';
async function run() {
await init();
const input = document.getElementById('input');
const submit = document.getElementById('submit');
const result = document.getElementById('result');
submit.addEventListener('click', () => {
const n = parseInt(input.value);
if (!isNaN(n) && n > 0) {
const prime = calculate_nth_prime(n);
result.textContent = `The ${n}${n % 10 === 1 && n !== 11 ? "st" : n % 10 === 2 && n !== 12 ? "nd" : n % 10 === 3 && n !== 13 ? "rd" : "th"} prime number is ${prime}.`;
} else {
result.textContent = 'Please enter a positive integer.';
}
});
}
run();
</script>
</body>
</