On Oct 31, 2017, at 9:07 AM, Stephen Canon via swift-dev <swift-dev@swift.org> wrote: > [Replying to the thread as a whole] > > There have been a bunch of suggestions for variants of `==` that either trap > on NaN or return `Bool?`. I think that these suggestions result from people > getting tunnel-vision on the idea of “make FloatingPoint equality satisfy > desired axioms of Equatable / Comparable”. This is misguided. Our goal is > (should be) to make a language usable by developers; satisfying axioms is > only useful in as much as they serve that goal. > > Trapping or returning `Bool?` does not make it easier to write correct > concrete code, and it does not enable writing generic algorithms that operate > on Comparable or Equatable. Those are the problems to be solved.
+100. Swift isn’t the first language to face the problems of floating point, nor is it the first to try to shoehorn it into a framework like Equatable. Despite weird cases involving NaNs, I haven’t seen a significant example of harm that it causes in practice, nor have I seen a proposal that makes the state of the art *better* than it currently is. IMO, better involves reducing existing pain without introducing new pains that are more significant than the old ones. -Chris _______________________________________________ swift-dev mailing list swift-dev@swift.org https://lists.swift.org/mailman/listinfo/swift-dev
