gistfile1.rs

use std::io;
use std::rand;

fn main() {
    let x:uint = rand::random();
    let secret_number:uint = (x % 100u) + 1u;

    println!("Guess the number!");

    loop{
        println!("Please input your guess.");

        io::stdin().

        let input = io::stdin().read_line().ok()
            .expect("Failed to read line");

        let input_num: Option<uint> = from_str(input.as_slice().trim());

        let num = match input_num {
            Some(num) => num,
            None      => {
                println!("Please input a number!");
                continue;
            }
        };

        println!("You guessed: {}", num);

        match cmp(num, secret_number) { 
            Less    => println!("Too small!"),
            Greater => println!("Too big!"),
            Equal   => { 
                println!("You win!"); 
                return;
            },
        }
    }
}

#[deriving(PartialEq,Show)]
enum Ordering {
    Less,
    Equal,
    Greater,
}

fn cmp(a: uint, b: uint) -> Ordering {
    if a < b { Less }
    else if a > b { Greater }
    else { Equal }
}