> On 8 Jun 2017, at 14:15, Vladimir.S <sva...@gmail.com> wrote: > >> On 08.06.2017 20:32, David Hart via swift-evolution wrote: >> Hello, >> When working with Strings which are known to be ASCII, I tend to use the >> UTF16View for the performance of random access. > > About the performance. Do we have a guarantee that 'barcode' declared in code > and/or containing only ASCII chars internally stored as UTF16 ? Otherwise, as > I understand, you'll have a performance penalty calling utf16 when internal > storage is in UTF8 for example, no?
I'm fairly sure the internal storage of String is always UTF16. > 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 >> swift-evolution@swift.org >> https://lists.swift.org/mailman/listinfo/swift-evolution _______________________________________________ swift-evolution mailing list swift-evolution@swift.org https://lists.swift.org/mailman/listinfo/swift-evolution