undefined | Better HN

0 pointsfrubar9y ago0 comments

If the type proved there could be no NaN, why would the check be needed?

0 comments

3 comments · 1 top-level

lifthrasiir9y ago· 2 in thread

0.0 is a finite number that yields NaN when divided by itself. The initial checking is not sufficient.

So check on construction, when doing operations with other unchecked floats, and when dividing. Any other operations that could produce a NaN?

Wait, are +-Inf considered unordered? Edit: Nope. inf == inf, so you should only have to worry about NaN. https://is.gd/Xi5jdr

lifthrasiir9y ago

If you want the full list: 0/0, ±inf/±inf, 0 x ±inf, ±inf x 0, inf + (-inf), (-inf) + inf, inf - inf, (-inf) - (-inf). This list is large enough to make NaN checking inefficient.

1 more reply

j / k navigate · click thread line to collapse