[swift-evolution] [Pitch] Introducing the "Unwrap or Die" operator to the standard library

Zach Waldowski zach at waldowski.me
Tue Jun 27 13:08:54 CDT 2017

Big +1.

Using `!` is widely seen as a smell. However, the need for it still
arises; they are preconditions, of a sort. It has become prevalent in my
teams’ codebases to do “guard else preconditionFailure”.
I like `!!` over something like `?!`; it follows the pattern that almost
every `?` in the language has an equivalent `!`.
The implementation details are ultimately not relevant to me. I’m a fan
of `Never` being a bottom type for more reasons than just this. I also
see no reason why operator funcs couldn’t accept file and line as extra
arguments on the rhs.
  Zachary Waldowski
  zach at waldowski.me

On Tue, Jun 27, 2017, at 01:16 PM, Erica Sadun via swift-evolution wrote:> Using an operator to provide feedback on the context of a failed
> unwrap has become a commonly implemented approach in the Swift
> developer Community. What are your thoughts about adopting this widely-
> used operator into the standard library?> 
> guard !lastItem.isEmpty else { return }
> let lastItem = array.last !! "Array must be non-empty"
> Details here:
> https://gist.github.com/erica/423e4b1c63b95c4c90338cdff4939a9b> 
> Thank you for your thoughtful feedback, -- E
> _________________________________________________
> swift-evolution mailing list
> swift-evolution at swift.org
> https://lists.swift.org/mailman/listinfo/swift-evolution

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.swift.org/pipermail/swift-evolution/attachments/20170627/a9ecce08/attachment.html>

More information about the swift-evolution mailing list