df_rust_match.rs

// creates a mpsc-channel for thread communication. 
// the type of the channel is inferred at compile-time
let (tx, rx) = mpsc::channel();
// (not shown) make the transmitter available to the other thread(s)
// ...

// start a new thread and capture the environment
thread::spawn(move || {
  let mut lines = Vec::new();
  // .. other variables omitted
  
  // execute the following block for all items that are received over the channel
  rx.iter().for_each(
    |req| {
      // modify the internal data struct `lines`, depending on the
      // type of received UpdateRequest
      match req {
        UpdateRequest::InitialUpdate { positioned_line } => {
            lines.push(positioned_line);
        }
        UpdateRequest::PositionUpdate { line_id, position } => {
             // ...
        }
        UpdateRequest::TextUpdate { line_id, new_text } => {
             // ...
        }
        UpdateRequest::SaveUpdate =>{
             // ...
        }
      }
      // save the result result
      // ...
    }
  );
  // this position will only be reached, when the channel closes
}