I’m sure it is, but this is not solving the right problem at all. Calendar is all UI. It needs to be lovingly gone over, not this.
The reimplementation itself is not 1.5x to 18x as fast as the C one. It is calling from Swift that is faster.
Yes, they correct in the parenthesis, but that's not how parenthetical expressions work:
A parenthetical expression is extra information added to a sentence or question that clarifies, explains, or adds information without changing the basic meaning. Think of it as an aside providing readers with helpful information that they don’t absolutely have to have, but that is helpful to them.
https://grammar.yourdictionary.com/style-and-usage/parenthet...
So basically, they are fixing the problem they've been having with bridging performance, which of course is due purely to them mis-designing Swift in such a way that it doesn't bridge well with all the existing code they have.
The reimplementation itself is 1.5x to 18x. They are using the parenthetical in precisely the way the style and usage guide suggests, adding the additional information that the new implementation is called from Swift.
> NSCalendar objects encapsulate information about systems of reckoning time in which the beginning, length, and divisions of a year are defined.
> The Swift overlay to the Foundation framework provides the Calendar structure, which bridges to the NSCalendar class.
https://developer.apple.com/documentation/foundation/nscalen...