use petgraph::graphmap::{DiGraphMap}; // 0.4.13

struct Something {
    exchange: String,
    from: String,
    to: String,
}


type GraphType<'a> = DiGraphMap<(&'a str, &'a str), f64>;
fn main() {
    let mut graph: GraphType = DiGraphMap::new();

    let mut i = 0;
    loop {
        // fetched from user STDIN input
        let something = Something { exchange: "Exchange".to_string(), from: "USD".to_string(), to: "BTC".to_string() };

        add_edges(&mut graph, &something);

        i+= 1;
        if i == 5 {
            break;
        }
    }


    println!("{:?}", graph);
}

fn add_edges(graph: &mut GraphType , something: &Something) {
    let a_exchange = something.exchange.clone();
    let b_exchange = something.exchange.clone();

    let a_from = something.from.clone();
    let b_to = something.exchange.clone();

    let edge_a: (&str, &str) = (&a_exchange, &a_from);
    let edge_b: (&str, &str) = (&b_exchange, &b_to);

    graph.add_edge(edge_a, edge_b, 23.);
}