[swift-evolution] [Pre-pitch] Conform Int (and others) to LosslessStringConvertible

[Niels Andriesse]

I'm +1 on this.

On Mon, 24 Jul 2017 at 15:37 Niels Andriesse via swift-evolution <
swift-evolution at swift.org> wrote:

> And CustomStringConvertible (to String) is basically the inverse of
> LosslessStringConvertible (from String).
> On Mon, Jul 24, 2017 at 3:23 PM, Niels Andriesse <andriesseniels at gmail.com
> > wrote:
>
>> Just want to point out that conforming Int to LosslessStringConvertible like
>> this would mean assuming a radix of 10 in the implementation. That said,
>> this would be consistent with the way Int implements
>> CustomStringConvertible, which also uses a radix of 10.
>>
>> On Mon, Jul 24, 2017 at 4:36 AM, David Sweeris via swift-evolution <
>> swift-evolution at swift.org> wrote:
>>
>>>
>>> On Jul 23, 2017, at 09:15, Matheus Martins via swift-evolution <
>>> swift-evolution at swift.org> wrote:
>>>
>>> I came across what i think is an inconsistency in the standard library.
>>>
>>> Why are some numeric types like Int not conforming to
>>> LosslessStringConvertible by default while Float and Double do conform to
>>> it in the standard library?
>>>
>>> I came across this while trying to write some generic code:
>>>
>>> func array<T: LosslessStringConvertible>(_ text: String) -> [T?] {
>>> return text.components(separatedBy: " ").map { T($0) }
>>> }
>>>
>>> It seems rather inconsistent to me that that allows me to do:
>>>
>>> let floats: [Float] = array("1.0 2.2 3")
>>>
>>> but i can't do:
>>>
>>> let ints: [Int] = array("1 2 3 4 5 6")
>>> "type 'Int' does not conform to protocol 'LosslessStringConvertible'"
>>>
>>> To further my point, Int is used as the sole example in the
>>> LosslessStringConvertible docs:
>>> http://swiftdoc.org/v3.0/protocol/LosslessStringConvertible/
>>> Yet it does not actually conform to it.
>>>
>>> This seems way too basic for me to feel comfortable pitching it here,
>>> but i searched and couldn't find any discussion on this on any mailing list
>>> or website.
>>>
>>>
>>> Sounds like it's a bug to me, either in the docs or stdlib, depending on
>>> the intended behavior. Although I doubt they would've used Int in the docs
>>> if they weren't intending Int to conform to it.
>>>
>>> - Dave Sweeris
>>>
>>> _______________________________________________
>>> swift-evolution mailing list
>>> swift-evolution at swift.org
>>> 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/20170725/180b95f9/attachment.html>