> On Feb 27, 2017, at 11:05 AM, Jordan Rose via swift-evolution > <swift-evolution@swift.org> wrote: > > >> On Feb 25, 2017, at 07:06, Ben Rimmington via swift-evolution >> <swift-evolution@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.
However, without doing anything, Numeric itself could serve the same type-erased box purpose. Since most arithmetic operations require `Self` arguments, they naturally wouldn't be available on the Numeric existential (unless someone designed and implemented an extension that handled up-conversion among arbitrary numeric types in the vein of Scheme's number tower or something like that). This seems like one place where that behavior would be desirable. -Joe _______________________________________________ swift-evolution mailing list swift-evolution@swift.org https://lists.swift.org/mailman/listinfo/swift-evolution
