[swift-evolution] Proposal: Add "none" and simplify the language.

[Félix Cloutier]

Yes, but following your suggestion, there may not be a difference between a non-optional value and an implicitly-wrapped optional, meaning that there will be a lot more of them.

Félix

> Le 7 janv. 2016 à 14:10:44, Amir Michail <a.michail at me.com> a écrit :
> 
> 
>> On Jan 7, 2016, at 2:09 PM, Félix Cloutier <felixcca at yahoo.ca <mailto:felixcca at yahoo.ca>> wrote:
>> 
>> That would leave you with runtime checks instead of compile-time checks and I totally disagree with that.
>> 
> 
> Implicitly unwrapped optionals do runtime checks also.
> 
>> Félix
>> 
>>> Le 7 janv. 2016 à 13:45:21, Amir Michail <a.michail at me.com <mailto:a.michail at me.com>> a écrit :
>>> 
>>> 
>>>> On Jan 7, 2016, at 1:40 PM, Félix Cloutier <felixcca at yahoo.ca <mailto:felixcca at yahoo.ca>> wrote:
>>>> 
>>>> An implicitly-unwrapped optional would do almost that, no?
>>>> 
>>> 
>>> You can use “none” to eliminate implicitly unwrapped optionals from the language.
>>> 
>>>> Félix
>>>> 
>>>>> Le 7 janv. 2016 à 12:46:53, Amir Michail via swift-evolution <swift-evolution at swift.org <mailto:swift-evolution at swift.org>> a écrit :
>>>>> 
>>>>> Examples:
>>>>> 
>>>>> var x:Int = none // uninitialized but not an optional
>>>>> 
>>>>> print(x) // run-time error as x is uninitialized
>>>>> 
>>>>> if x == nil { … } // compile time error… x can never be nil because it is not an optional
>>>>> 
>>>>> if x == none { x = 2 } // … but it can be uninitialized
>>>>> 
>>>>> Optionals can also be uninitialized:
>>>>> 
>>>>> var y:Int? = none // uninitialized and an optional
>>>>> 
>>>>> if y == nil { … } // run-time error as y is uninitialized
>>>>> 
>>>>> y = nil
>>>>> 
>>>>> if y == nil { … } // fine
>>>>> 
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>>>> 
>>> 
>> 
> 

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