[swift-evolution] ternary operator ?: suggestion

[David Owens II]

There’s no need for the “then" keyword if you just allow if-expressions as well.

```
let result = if condition { 1 } else { 2 }
```

Or more verbosely:

```
let result =
    if condition {
        return 1
    }
    else {
        return 2
    }
```

The same could be for switch statements as well.

```
let result = switch item {
    case foo: 1
    case bar: 2
}
```

The above assume implicit returns on single-line statements on the condition/case branches.

-David

> On Dec 3, 2015, at 11:26 PM, David Hart <david at hartbit.com> wrote:
> 
> I also tend to agree but I don't like the ordering in the Python version and would rather see the introduction of the then keyword
> 
> On 04 Dec 2015, at 06:08, Sean Heber <sean at fifthace.com <mailto:sean at fifthace.com>> wrote:
> 
>> I agree that using ? for ternary feels.. uncomfortable in Swift. I wouldn't mind seeing Python-style or just eliminating it entirely in favor of simplicity.
>> 
>> l8r
>> Sean
>> 
>> On Dec 3, 2015, at 10:48 PM, Dan Appel <dan.appel00 at gmail.com <mailto:dan.appel00 at gmail.com>> wrote:
>> 
>>> I agree that ternary can make code unreadable, especially so with the ‘?’. I personally like the Haskel option the most, but it introduces a new keyword ‘then’, which isn’t great either. Python’s "y if x else z" is therefore, in my opinion, the best alternative.
>>> 
>>> Also, I found it interesting how split the Rust community was about removing the ternary operator.
>>> 
>>> — 
>>> Dan Appel
>>> 
>>> On Thu, Dec 3, 2015 at 7:58 PM J. Cheyo Jimenez <cheyo at masters3d.com <mailto:cheyo at masters3d.com>> wrote:
>>> Would you consider replacing the C style ?: ternary operator to something that does not use the question mark and colon ? 
>>> 
>>> The use of "?" can be confusing when speed reading code with optionals. 
>>> 
>>> Consider this code as somebody learning swift as their first language.
>>> let result = !condition ? 1 : 2
>>> 
>>> 
>>> Some alternatives:
>>> 
>>> Haskel 
>>> if predicate then expr1 else expr2
>>> Python
>>> result = x if a > b else y
>>> The advantage of not using the question mark is that the language will be more consistency on the use of "?" to mean only optionals. 
>>> 
>>> 
>>> References:
>>> https://devforums.apple.com/message/1020139#1020139 <https://devforums.apple.com/message/1020139#1020139>
>>> https://github.com/rust-lang/rust/issues/1698#issuecomment-3705066 <https://github.com/rust-lang/rust/issues/1698#issuecomment-3705066> _______________________________________________
>>> swift-evolution mailing list
>>> swift-evolution at swift.org <mailto:swift-evolution at swift.org>
>>> https://lists.swift.org/mailman/listinfo/swift-evolution <https://lists.swift.org/mailman/listinfo/swift-evolution>
>>> 
>>> _______________________________________________
>>> swift-evolution mailing list
>>> swift-evolution at swift.org <mailto:swift-evolution at swift.org>
>>> https://lists.swift.org/mailman/listinfo/swift-evolution <https://lists.swift.org/mailman/listinfo/swift-evolution>
>> 
>> _______________________________________________
>> swift-evolution mailing list
>> swift-evolution at swift.org <mailto:swift-evolution at swift.org>
>> https://lists.swift.org/mailman/listinfo/swift-evolution <https://lists.swift.org/mailman/listinfo/swift-evolution>
> 
> _______________________________________________
> swift-evolution mailing list
> swift-evolution at swift.org
> https://lists.swift.org/mailman/listinfo/swift-evolution

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.swift.org/pipermail/swift-evolution/attachments/20151204/e4d7cf1c/attachment-0001.html>