[swift-evolution] [Re-Review] SE-0104: Protocol-oriented integers

Jordan Rose jordan_rose at apple.com
Mon Feb 27 13:05:49 CST 2017

> On Feb 25, 2017, at 07:06, Ben Rimmington via swift-evolution <swift-evolution at swift.org> wrote:
> <https://github.com/apple/swift-evolution/blob/master/proposals/0104-improved-integers.md>
>> On 24 Feb 2017, at 02:05, Ben Cohen wrote:
>> Regarding the “Number” protocol: it was felt this is likely to cause confusion with NSNumber, given the NS-prefix-dropping versions of other Foundation types indicate a value-typed concrete type equivalent, which this won’t be. The recommendation is to use “Numeric" instead.
> Does the `Error` protocol cause confusion with the `NSError` class?
> I think `Number` is better than `Numeric`, because it is consistent with `SignedNumber`.

Error and NSError are actually related types, like String and NSString, and are used in roughly the same way. Numeric and NSNumber serve very different purposes: the former is a protocol for various operations, and the latter is a semi-type-erased class box around a *cough* numeric value that (deliberately) doesn't implement most of the operations in the protocol.


More information about the swift-evolution mailing list