Is there a reason that a throwing unwrap function/operator isn’t part of the
standard library? Seems like it would be handy to be able to have a one-liner
for attempting to unwrap and throw if it’s nil. Something like
postfix operator .?!
extension Optional {
static postfix func .?!(optional: Optional<Wrapped>) throws -> Wrapped {
switch optional {
case let .some(wrapped):
return wrapped
case .none:
throw UnwrapError()
}
}
}
init?(data: [String: Any]) {
do {
self.someProperty = try data["some_key”].?!
self.anotherProperty = try data["another_key”].?!
} catch is UnwrapError {
return nil
}
}
> On Jul 26, 2017, at 12:13 PM, Chris Lattner via swift-evolution
> <[email protected]> wrote:
>
>
>> On Jul 25, 2017, at 2:44 AM, philohan95 via swift-evolution
>> <[email protected]> wrote:
>>
>> I think the current way to initiate models in a Failable Initializer
>> `init?()` is overly verbose and should be shortened down so less boilerplate
>> should be needed.
>>
>> The current way:
>>
>> ```
>> let someProperty: Any
>> let anotherProperty: Any
>>
>> init?(data: [String: Any]) {
>> guard
>> let someProperty = data["some_key"],
>> let anotherProperty = data["another_key"]
>> else {
>> return nil
>> }
>>
>> self. someProperty = someProperty
>> self. anotherProperty = anotherProperty
>> }
>> ```
>
> Guard isn’t really the right answer for this, I’d try something like this
> (where unwrapOrThrow is the obvious generic function you can define yourself):
>
> init?(data: [String: Any]) {
> do {
> self.someProperty = try unwrapOrThrow(data["some_key”])
> self.anotherProperty = try unwrapOrThrow(data["another_key”])
> } catch {
> return nil
> }
> }
>
> -Chris
>
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