This problem is not limited to JSON. I have scads of underscored variables
and guard bindings in my code because of this limitation, though I rarely
work with JSON.
On Tue, Jul 25, 2017 at 5:13 PM, Niels Andriesse <andriesseni...@gmail.com>
wrote:
> Although I have come across this problem as well (particularly when
> initializing from JSON), I don't think the solution is to fundamentally
> change initialization behavior like this, because 1. ) that is probably
> going to break a good deal of existing code and 2. ) I think that the
> introduction of the Codable protocol in Swift 4 will eliminate most cases
> where this is really a problem.
>
> On Wed, 26 Jul 2017 at 02:30 Taylor Swift via swift-evolution <
> swift-evolution@swift.org> wrote:
>
>> I’d be in favor of this.
>>
>> On Tue, Jul 25, 2017 at 5:44 AM, philohan95 via swift-evolution <
>> swift-evolution@swift.org> 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
>>> }
>>> ```
>>>
>>> As you can see we had to use the properties twice (this would also be
>>> the case of `if let`) making the initializer twice as long as necessary and
>>> becomes a pain to implement when having more than 1 property.
>>>
>>> My idea is extending the power of the `guard` statement
>>>
>>> Idea:
>>> init?(data: [String: Any]) {
>>> guard
>>> someProperty = data["some_key"], // Currently
>>> fails because `self` us used before all stored properties are initialized
>>> anotherProperty = data["another_key"]
>>> else {
>>> return nil
>>> }
>>> }
>>> }
>>>
>>> _______________________________________________
>>> swift-evolution mailing list
>>> swift-evolution@swift.org
>>> https://lists.swift.org/mailman/listinfo/swift-evolution
>>>
>>
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>>
>
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