extern crate rand;

use std::fs;
use rand::{thread_rng, Rng};

fn main() {
    let mut rng = thread_rng();

    let ions = fs::read_string("ions.txt").unwrap();
    let names_and_formulae = ions.lines()
        .for_each(|line| line.split('-'))
        .collect::<Vec<_>>();

    loop {
        let mut num = rng.gen_range(0, names_and_formulae.len());

        let (name, formula) = names_and_formulae[num];

        num = rng.gen_range(0, 2);

        if num == 0 {
            print!("Formula for {}? ", name);

        } else {

        }
    }
}