On Jun 28, 2017, at 6:43 PM, Alan Westbrook via swift-evolution <[email protected]> wrote: > > >> On Jun 28, 2017, at 5:27 PM, Xiaodi Wu via swift-evolution >> <[email protected] <mailto:[email protected]>> wrote: >> >> In the initial example, repeated here in largely identical form, the desired >> comment is "array must be non-empty." In what way does that provide more >> information than a bare `!`? > > I’m going to second this sentiment with the feeling that the message is > seemingly redundant. It feels akin to the comment in this line of code: > > let value = 1 // This value is set to 1 > > On an error, one gets the trap with the optional unwrapped message, and goes > to the code where they see what is being forced by assumption. > > Does the message spelling out the code in natural language help? > > Alan
I have replied to another email but will repeat the point here: The proposed `!!` operator differs from the direct use of `!` in that it explains a fact known to hold true, allowing the lhs to safely unwrap. The alternatives are: * forced unwrap -- comments do not transfer to runtime, which leads coders to use: * using guard with fatalError -- the !! operator provides an elegant sugared shortcut for this common code -- E
_______________________________________________ swift-evolution mailing list [email protected] https://lists.swift.org/mailman/listinfo/swift-evolution
