Spaceship Operator

[Mike Samuel]

On Tue, Jun 27, 2017 at 4:29 PM, Isiah Meadows <isiahmeadows at gmail.com> wrote:
> Inline
>
> On Tue, Jun 27, 2017, 16:19 Mike Samuel <mikesamuel at gmail.com> wrote:
>>
>> On Tue, Jun 27, 2017 at 4:13 PM, Isiah Meadows <isiahmeadows at gmail.com>
>> wrote:
>> > For what it's worth, for most practical purposes, `arr.sort((a, b) => b
>> > -
>> > a))` works well enough. (The only thing it doesn't work well with are
>> > NaNs,
>> > but in practice, those almost never occur.)
>>
>> Don't numeric comparison operators typically sort -0 before +0?
>
>
> In JavaScript, not if I recall correctly. The only places where signed
> zeroes are relevant is in division.

There are others.
Math.sign(-0)


>>
>> ((a,b)=>b-a) is also problematic for an array that contains two or
>> more infinite values with the same sign and one or more finite values
>> since isNaN(Infinity-Infinity).   That NaN from the comparator can be
>> triggered or not based on details of the sorting algo and the precise
>> placement on the Infinities.
>
>
> Infinities have also been similarly rare for me except in isolation.

Fair enough.  There are more builtins that produce Infinity though.
JSON.parse('1e1000')