input_macro

A simple and safe input macro for Rust, inspired by Python's input().

Motivation

Rust's standard library currently lacks a simple way to read user input and parse it into different types, similar to Python's input(). This can make simple programs and examples more complex than necessary, especially for beginners. This library aims to fill that gap by providing a user-friendly macro.

Features

• Easy to use: The input! macro provides a simple interface for reading user input.
• Type inference: The macro automatically infers the desired type based on the variable it's assigned to.
• Error handling: It handles both I/O errors and parsing errors gracefully, returning a Result.
• Optional prompt: You can provide an optional prompt string that will be printed before reading input.
• Flushing: The prompt is automatically flushed to ensure it's visible to the user before input is read.
• Safety: The macro is designed to be safe and prevent common errors like buffer overflows.
• Performance: It's built on top of Rust's efficient I/O and string handling.
• EOF Handling: Returns Ok(None) on EOF, allowing for graceful handling of end-of-file conditions.

Usage Examples

use input_macro::input;

fn main() {
    // Read a line of text into a String
    let name: String = input!("Enter your name: ").unwrap();
    println!("Hello, {}!", name);

    // Read an integer
    let age: i32 = input!("Enter your age: ").unwrap();
    println!("You are {} years old.", age);

    // Read a floating-point number
    let price: f64 = input!().unwrap(); // No prompt
    println!("The price is {}.", price);

    // Handle potential errors
    let num: Result<i32, _> = input!();
    match num {
        Ok(n) => println!("You entered: {}", n),
        Err(e) => eprintln!("Invalid input: {}", e),
    }

    // Example of handling EOF
    loop {
        let line: Option<String> = input!().unwrap();
        match line {
            Some(value) => println!("You entered: {}", value),
            None => {
                println!("End of input reached.");
                break;
            }
        }
    }
}