[swift-evolution] Guard Implicit Fallback

[Ilya Belenkiy]

Losing brackets around the return would mean that no additional statements
(for example logging or some other useful thing) will be possible in the
early return

On Fri, Feb 12, 2016 at 2:26 AM ilya via swift-evolution <
swift-evolution at swift.org> wrote:

> Agreed that explicit return is more readable.
> I'd be happy to lose brackets around return though:
>
> guard let value = optional else return
>
> On Thu, Feb 11, 2016 at 18:46 Xiaodi Wu via swift-evolution <
> swift-evolution at swift.org> wrote:
>
>> I believe this has already been proposed on the list in the past. I don't
>> have easy access to the archives at the moment so I can't provide a
>> convenient link.
>>
>> The gist of it--or at least one of the compelling arguments against the
>> idea--was that the 'obvious' implicit behavior becomes non-obvious when you
>> take into account guard statements inside loops, for example. Do you
>> continue? break? return? And once you make a decision for each of the
>> scenarios envisioned you end up with a complicated series of fallbacks that
>> need extensive documentation, which is no longer much of a win over
>> explicitly writing your fallback.
>> On Thu, Feb 11, 2016 at 11:38 AM Developer via swift-evolution <
>> swift-evolution at swift.org> wrote:
>>
>>> I agree the nil fallback case is a common one, but the loss of
>>> readability and decreased understanding of control flow here makes me think
>>> special-casing this isn't all it's cracked up to be.
>>>
>>> ~Robert Widmann
>>>
>>> 2016/02/10 22:40、Tighe Racicot via swift-evolution <
>>> swift-evolution at swift.org> のメッセージ:
>>>
>>> Hey everyone,
>>>
>>> I feel that `guard` could be a little more Swifty and would like to
>>> start a conversation concerning it.
>>>
>>> For example, I often have a function whose job depends on an optional
>>> having a value, and so I guard-let at the start and return if the guard
>>> fails. Or if the function returns an optional type, I'll simply return nil
>>> if guard fails.
>>>
>>> Can we improve on the general fallback case? Could we simply say:
>>>
>>> func noReturn() {
>>>     guard let aValue = someOptional
>>>     ....
>>> }
>>>
>>> and have that imply "else { return *void or nil* }"
>>>
>>> What are your thoughts?
>>>
>>> Tighe
>>>
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