I'm glad that you agree with me. However, my proposal has been marked as out of
scope for swift 3.0, so we'll have to wait a month or so to bring this back up
again.
> On Jul 13, 2016, at 10:24 AM, char...@charlesism.com
> <charlesism....@gmail.com> wrote:
>
> +1
>
> I'm in favour of this, or something similar. It currently requires a bit more
> effort to deal with an optional that appears as an argument. It would be a
> bit nicer to make decisions about control flow when the amount of effort your
> choices require aren't affected by things like this.
>
>
>
> Sent from my iPhone
>
>> On Jul 12, 2016, at 7:16 AM, Liam Stevenson via swift-evolution
>> <swift-evolution@swift.org> wrote:
>>
>> Optional chaining is one of the great, useful features of Swift. It can be
>> used “for querying and calling properties, methods, and subscripts on an
>> optional that might currently be nil,” to quote Apple's "The Swift
>> Programming Language.” However, often it is necessary to call a function,
>> subscript, or initializer conditionally based on if one or more parameters
>> are nil. The proposed solution is to allow a question mark (?) to be placed
>> after an optional value wished to be used as a parameter. Then, the
>> function, initializer, or subscript will be called if and only if the
>> parameter's value is not nil. If it has a return type, it will return an
>> optional, which will be nil if the parameter is nil.
>>
>> Old way (with seemingly unnecessary if statement considering the flexibility
>> provided by optional chaining):
>> var arr = ["apples", "oranges", "pears", "bananas"]
>> let index: Int? = 2
>>
>> var removedElement: String?
>> if let index = index {
>> removedElement = arr.removeAtIndex(index) //sets removedElement
>> to "pears"
>> }
>> Using this proposal:
>> var arr = ["apples", "oranges", "pears", "bananas"]
>> let index: Int? = 2
>>
>> var removedElement: String?
>> removedElement = arr.removeAtIndex(index?) //sets removedElement to
>> “pears"
>> Another similar example:
>> Old way:
>> var arr = ["apples", "oranges", "pears", "bananas"]
>> let index: Int? = nil
>>
>> var removedElement: String?
>> if let index = index {
>> removedElement = arr.removeAtIndex(index) //never called
>> }
>> Using this proposal:
>> var arr = ["apples", "oranges", "pears", "bananas"]
>> let index: Int? = nil
>>
>> var removedElement: String?
>> removedElement = arr.removeAtIndex(index?) //removeAtIndex is never
>> called, and removedElement is set to nil
>>
>> What does everyone think of this proposal? It is additive so it will not
>> break any existing code, and in the future it will provide conciseness and
>> clarity since the syntax is similar to the existing optional chaining syntax.
>>
>> View the full proposal on GitHub here:
>> https://github.com/liam923/swift-evolution/blob/master/proposals/NNNN-extend-optional-chaining-to-function-initializer-and-subscript-parameters.md
>>
>> Liam
>> _______________________________________________
>> swift-evolution mailing list
>> swift-evolution@swift.org
>> https://lists.swift.org/mailman/listinfo/swift-evolution
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