> On Feb 8, 2017, at 12:00 PM, Jack Newcombe via swift-evolution
> <swift-evolution@swift.org> wrote:
>
> I propose the introduction of a nil-rejection operator (represented here as
> !!) as a complement to the above operators.
> .
> This operator should allow an equivalent behaviour to the forced unwrapping
> of a variable, but with the provision of an error to throw in place of
> throwing a fatal error.
>
> - value !! Error :
> if value is nil, throw non-fatal error
> if value is not nil, return value
>
> Example of how this syntax might work (Where CustomError: Error):
>
> let value = try optionalValue !! CustomError.failure
Rather than invent a new operator, I'd prefer to make `throw` an expression
rather than a statement. Then you could write:
let value = optionalValue ?? throw CustomError.Failure
One issue here would be figuring out the proper return type for `throw`.
Although if `Never` were a subtype-of-all-types, that would of course work. :^)
--
Brent Royal-Gordon
Architechies
_______________________________________________
swift-evolution mailing list
swift-evolution@swift.org
https://lists.swift.org/mailman/listinfo/swift-evolution
