[swift-evolution] Brainstorming: Optional sugar inferred map

[Jacob Bandes-Storch]

That'd be the point. If doSomething were not optional, when "n?" appears in
it, it becomes optional (it's basically optional chaining, but for function
calls and other expressions instead of just dot-notation).
On Thu, Jan 28, 2016 at 8:38 PM Craig Cruden <ccruden at novafore.com> wrote:

>
>     manager.doSomething(data: data, count: n?)
>
>
> What if the return value of doSomething is not an optional?  Expressions
> are easy — but there might be some conflicts with this one.
>
>
> On 2016-01-28, at 14:34:58, Jacob Bandes-Storch via swift-evolution <
> swift-evolution at swift.org> wrote:
>
> I've wanted this sort of thing a lot. It would also work for other
> functions, such as
>
>     manager.doSomething(data: data, count: n?)
>
> which is equivalent to
>
>     n.map { manager.doSomething(data: data, count: $0) }
>
> It might be hard to see exactly which operator/function applications such
> a thing applies to, if used in the context of a complex expression.
>
> Jacob
>
> On Wed, Jan 27, 2016 at 9:50 PM, Paul Ossenbruggen via swift-evolution <
> swift-evolution at swift.org> wrote:
>
>> Maybe something like this?
>>
>> let n : Int? = 5
>>
>> let r = n? + 5
>>
>>
>> On Jan 27, 2016, at 9:46 PM, Thorsten Seitz <tseitz42 at icloud.com> wrote:
>>
>> Too much hidden magic IMO. This would mean loosing the benefits of
>> optionals, i.e. making explicit where optional cases occur and that
>> handling the missing case has to be considered.
>>
>> -Thorsten
>>
>> Am 28.01.2016 um 06:30 schrieb Craig Cruden via swift-evolution <
>> swift-evolution at swift.org>:
>>
>> Yes
>>
>> On 2016-01-28, at 12:28:40, Paul Ossenbruggen <possen at gmail.com> wrote:
>>
>> Trying to see if I got this. So the type of r would be Int? at the end of
>> this? And if n were nil then r would be nil? Otherwise it r is 10?
>>
>>
>>
>> On Jan 27, 2016, at 9:19 PM, Craig Cruden via swift-evolution <
>> swift-evolution at swift.org> wrote:
>>
>> Swift currently encourages a lot of conditional code - especially when it
>> comes to optionals.  In most cases when you are computing etc. on an
>> Optional you would expect that you would want an optional result and things
>> to be able to use optionals.
>>
>> In another language I generally just `map` one optional to another -
>> which may not be the most readable code to some not use to optionals.
>>
>> I was wondering if maybe an expression is not available that it would
>> rewrite the syntax to map from one to another value.
>>
>> So things like:
>>
>> let n : Int? = 5
>>
>> let r = n + 5
>>
>> would actually compile as
>>
>> let r = n.map {$0 + 5}
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