(-1) % 1 evaluates to +0, not -0

[kurgm]

Description: The abstract operation Number::remainder(n, d) returns +0_𝔽 when n and d are finite and non-zero and n is divisible by d, even if n is negative. For example, when n = -1 and d = 1, algorithm step 8 returns 𝔽(0), which is +0_𝔽. Accordingly, the expression (-1) % 1 evaluates to +0_𝔽. This behavior is different from that of ES6 (and JS engines) in which it evaluates to -0 by the following rule in 12.6.3.3 Applying the % Operator:

The sign of the result equals the sign of the dividend.

eshost Output:

$ eshost -s -e "Object.is(-0, (-1) % 1)"
#### ChakraCore, SpiderMonkey, V8
true

[ljharb]

https://tc39.es/ecma262/#sec-numeric-types-number-remainder suggests to me that it would reach step 7 with n as -1𝔽 and d as 1𝔽.

It seems like you're saying that step 7 produces a mathematical zero, and that step 8, for the case when n and d have the opposite sign and when r is 0, it should explicitly return -0𝔽?

[kurgm]

It seems like you're saying that step 7 produces a mathematical zero,

Yes exactly.

and that step 8, for the case when n and d have the opposite sign and when r is 0, it should explicitly return -0𝔽?

I think it's not when n and d have the opposite sign, but when n is negative (and when r is zero).

Thank you for the quick reply!

[michaelficarra]

This was accidentally introduced in #2189. It looks like we should insert a step after 7 like

1. If _r_ is 0 and _n_ is negative, return *-0*<sub>𝔽</sub>.

@kurgm Would you like to submit a PR?

[kurgm]

Yes, I'll do.