> On 8 Jun 2017, at 12:35, Tony Allevato <[email protected]> wrote:
> 
> It is an extremely rare case for a developer to know a priori what literal 
> numeric indices should be used when indexing into a string, because it only 
> applies when strings fall into a very specific format and encoding.
> 
> It's been discussed before during String-related proposals but AFAIK the core 
> team has come out against it—it would be an invitation for users who don't 
> understand the distinction to do very unsafe and wrong things with strings. 
> IMO, writing your own extension or using index.offset(by:) isn't a huge 
> penalty here.

Is it really an invitation when it’s hidden inside the UTF16View?

> On Thu, Jun 8, 2017 at 10:32 AM David Hart via swift-evolution 
> <[email protected] <mailto:[email protected]>> wrote:
> Hello,
> 
> When working with Strings which are known to be ASCII, I tend to use the 
> UTF16View for the performance of random access. I would also like to have the 
> convenience of indexing with Int:
> 
> let barcode = "M1XXXXXXXXX/CLEMENT   EELT9QBQGVAAMSEZY1353 244 21D 531  
> 10A1311446838”
> let name = barcode.utf16[2..<22]
> let pnrCode = barcode.utf16[23..<30]
> let seatNo = barcode.utf16[47..<51]
> let fromCity = barcode.utf16[30..<33]
> let toCity = barcode.utf16[33..<36]
> let carrier = barcode.utf16[36..<39]
> let flightNumber = barcode.utf16[39..<44]
> let day = barcode.utf16[44..<47]
> 
> I define my own subscript in an extension to UTF16View but I think this 
> should go in the Standard Library.
> Any thoughts?
> 
> David.
> _______________________________________________
> swift-evolution mailing list
> [email protected] <mailto:[email protected]>
> https://lists.swift.org/mailman/listinfo/swift-evolution 
> <https://lists.swift.org/mailman/listinfo/swift-evolution>

_______________________________________________
swift-evolution mailing list
[email protected]
https://lists.swift.org/mailman/listinfo/swift-evolution

Reply via email to