> I didnt say it was unsafe, I said it crashes.

Your phrasing implied that you said the crash was not safe, as you put "unsafe" in quotes and contrasted it with the crash. At least, that's what I understood you to be saying too.

>An application error (returned null) shouldn't abort your application with a hard error, no logs. Its just plain poor practice to use unwrap().

What? That's what every other language does.

  file.open("foo").read_line()

If open fails it'll either throw or return null which will then cause read_line to throw a null pointer exception. Rust just makes things explicit here.

Though it might be interesting if there was a special opt-in Deref impl for Result and Option so people could omit the unwrap and just get it implicitly, for the occasions when you don't want that explicitness.

> unwrap [...] causes application level crashes in way that is very much easier to avoid in other languages

Unwrap does what just about every other language with exceptions-by-default does: it prints out a message for developers and exits. If you don't want that behavior, that's fine; in Rust you'd not use unwrap(), and in other languages you'd catch the exception.

Now, I agree that if you are using a library which does unwrap() in Rust vs a library that throws an exception in Python, you have different situations. But unwrap() isn't meant to be used in libraries (or if it is, only for fatal errors which should be uncatchable).

> Whats (sic) your justification for unwrap? I've never seen a meaningful justification for it other than not wanting to handle errors properly.

That is the justification for it: you are writing a simple short script-like tool (or you are prototyping or exploring some problem through one-off or throw-away code) and you want any errors to immediately exit with a developer-centric message and failure code. unwrap() is perfect for this.

It's the same justification for not catching every exception in other languages. Sometimes you are fine with an error printing a message and exiting.