A simple Rust command-line calculator

rust_calculator.rs

use std::io;

fn main() {
    println!("Simple Rust Calculator");
    println!("--------------------");

    loop {
        let mut input = String::new();
        println!("Enter the first number:");
        io::stdin().read_line(&mut input).expect("Failed to read line");
        let first_number: f64 = match input.trim().parse() {
            Ok(num) => num,
            Err(_) => {
                println!("Invalid number. Please try again.");
                continue;
            }
        };

        input.clear();
        println!("Enter the operator (+, -, *, /):");
        io::stdin().read_line(&mut input).expect("Failed to read line");
        let operator: char = match input.trim().chars().next() {
            Some(op) => op,
            None => {
                println!("Invalid operator. Please try again.");
                continue;
            }
        };

        input.clear();
        println!("Enter the second number:");
        io::stdin().read_line(&mut input).expect("Failed to read line");
        let second_number: f64 = match input.trim().parse() {
            Ok(num) => num,
            Err(_) => {
                println!("Invalid number. Please try again.");
                continue;
            }
        };

        let result = match operator {
            '+' => first_number + second_number,
            '-' => first_number - second_number,
            '*' => first_number * second_number,
            '/' => {
                if second_number == 0.0 {
                    println!("Error: Division by zero!");
                    continue;
                }
                first_number / second_number
            }
            _ => {
                println!("Invalid operator. Please use +, -, *, or /.");
                continue;
            }
        };

        println!("The result is: {}", result);

        input.clear();
        println!("Do you want to perform another calculation? (y/n)");
        io::stdin().read_line(&mut input).expect("Failed to read line");
        if input.trim().to_lowercase() != "y" {
            break;
        }
    }
}