[swift-evolution] [Proposal] Remove force unwrapping in function signature.

[Saagar Jha]

Wait, it looks like String(byRepeatingString: aString, count: 3) only works
on characters and was removed, replace it with aString + aString + aString.


On Fri, Jun 10, 2016 at 7:38 PM Saagar Jha <saagarjha28 at gmail.com> wrote:

> Yes, that’s what I meant. Basically, I see stuff like this:
>
> func tripleForceUnwrapping(aString: String!) -> String {
>     return String(byRepeatingString: aString, count: 3)
> }
>
> and later users get a crash with this:
>
> let possiblyNilString = someFunctionThatRetunsAnOptional()
> tripleForceUnwrapping(possiblyNilString)
>
> even though it compiles fine.
>
> func tripleWithoutUnwrapping(aString: String?) -> String {
>     return String(byRepeatingString: aString, count: 3)
> }
>
> let possiblyNilString = someFunctionThatRetunsAnOptional()
> tripleWithoutUnwrapping(possiblyNilString)
>
> meanwhile, doesn’t compile and forces the user to think “huh, it’s not
> compiling because there’s an Optional” and hopefully add a check
>
>
> On Fri, Jun 10, 2016 at 7:18 PM Paul Cantrell via swift-evolution <
> swift-evolution at swift.org> wrote:
>
>>
>> > On Jun 10, 2016, at 7:43 PM, Dave Abrahams via swift-evolution <
>> swift-evolution at swift.org> wrote:
>> >
>> > on Thu Jun 09 2016, Saagar Jha <swift-evolution at swift.org> wrote:
>> >
>> >> Yes, that’s exactly my point. Force unwrapping optionals adds
>> >> confusion for new users; all too often I see newcomers ending up with
>> >> the assumption that the force unwrapping takes care of the check for
>> >> them.
>> >
>> > ...but, it *does*.
>>
>> I took Saagar to mean “the assumption that force unwrapping takes care of
>> doing the right thing for them so they don’t ever have to think about nil
>> at all.” Which is indeed quite common in beginner Swift code.
>>
>> Sadly, there is no compile-time check for mindfulness.
>>
>> Cheers, P
>>
>> _______________________________________________
>> swift-evolution mailing list
>> swift-evolution at swift.org
>> https://lists.swift.org/mailman/listinfo/swift-evolution
>>
> --
> -Saagar Jha
>
-- 
-Saagar Jha
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