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Comment by ilaksh | Hacker News Reader

How many other ways to handle errors are there besides the three you mentioned? Why not just default to panic then if you are going to have to type unwrap everywhere? Does typing that all over the place prevent you from having errors in production?

The whole thing is asinine. Its the worst part of programmer culture.

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You can write unwrap in production, if you know that the error isn't supposed to happen. But Rust's error handling forces you to think about errors and how to handle them, by design. Rust's way is also much more efficient at runtime, because using stack unwinding to recover from every error would be slow in the cases where errors are an expected and normal part of operation.

Question 1: because it's the wrong default for robust code.

Question 2: no, you don't use unwrap in production.

Jesus. What would the 'correct' MIO production code look like without unwraps? Or is that a PhD research project, 'correctly' implementing this page of code for 'production'?

If this were not happening in main(), then the following would be one way of handling the errors.

  fn foo() -> Result<(),Error> {
      // Create an event loop
      let mut event_loop = try!(EventLoop::<(), u64>::new());
      let sender = event_loop.channel();
      for i in 0.. 5 {
          try!(sender.send(i));
      }
      // Start it
      try!(event_loop.run(&mut BearHandler(0));
  }

You can always use `map`, `and` and `and_then`.

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