[swift-evolution] [Idea] Bringing the partial/total ordering distinction into Comparable

Dave Abrahams dabrahams at apple.com
Mon Apr 25 18:08:03 CDT 2016

on Sun Apr 24 2016, Brent Royal-Gordon <swift-evolution at swift.org> wrote:

>> Regarding how this affects sorting methods though, some people (myself included) like the simplicity of being able to do the following:
>> 	myArray.sort(>)	// If array is of Comparable elements, just throw in the operator
> That is extremely convenient. With my proposed extensions, it's actually writeable as this:
> 	myArray.sorted { ($0 <=> $1).reversed() }
> But that's obviously much less convenient. It's also equivalent to this:
> 	myArray.sorted { $1 <=> $0 }
> Which means, with the proper higher-order function, it's the same as this:
> 	myArray.sorted(flip(<=>))

There's no reason we can't accept both kinds of ordering function, though it
does expand the overload set, which is a usability downside.


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