hello_server.rs

extern crate iron;
extern crate mysql;

use iron::prelude::*;
use iron::status;
use iron::{Handler};

struct Router {
  routes: HashMap<String, Box<Handler>>
}
impl Router {
  fn new() -> Self {
    Router { routes: HashMap::new() }
  }
  
  fn add_route<H>(&mut self, path: String, handler: H) where H: Handler {
    self.routes.insert(path, Box::new(handler));
  }
}
impl Handler for Router {
  fn handle(&self, req: &mut Request) -> IronResult<Response> {
    match self.routes.get(&req.url.path().join("/")) {
      Some(handler) => handler.handle(req),
      None          => Ok(Response::with(status::NotFound))
    }
  }
}

fn main() {
  let pool = mysql::Pool::new("mysql://root:password@localhost:3306/some_db").unwrap();
  let mut router = Router::new()
  
  router.add_route("hello".to_string(), |_: &mut Request| {
    // use `pool` to read info from DB
    // error: closure may outlive the current function, but it borrows `pool`, which is owned by the current function [E0373]
    Ok(Response::with((status::Ok, "some data retrieved from DB")))
  });
  
  Iron::new(router).http("localhost:3000").unwrap();
}