[csswg-drafts] [css-syntax-3][css-values-4] Add informative note about tokenization of negative 0 (#7472)

cdoublev has just created a new issue for https://github.com/w3c/csswg-drafts:

== [css-syntax-3][css-values-4] Add informative note about tokenization of negative 0  ==
I cannot tell which behavior is "right", if there is one, and I cannot think of an example for which it could matter, but I feel like an informative note (something like the note removed in this [commit](https://github.com/w3c/csswg-drafts/commit/3eeafc30400155ab02e7934c522689ec06f9af1b#diff-fc1c32de78d227c8f0c8008469824444d1ba7f027e48a336125017d40b8f6f6fL3463)) about removing the sign of `0⁻` in [*convert a string to a number*](https://drafts.csswg.org/css-syntax-3/#convert-a-string-to-a-number) is required, especially in regards to calculations because a consequence is that `calc(1 / -0)` is `calc(infinity)` instead of `calc(-infinity)`, which matches the output in JS, which [*performs division according to the rules of IEEE 754-2019*](https://tc39.es/ecma262/multipage/ecmascript-data-types-and-values.html#sec-numeric-types-number-divide), whereas in [Type Checking (CSS Values)](https://drafts.csswg.org/css-values-4/#calc-type-checking):

> Math functions follow IEEE-754 semantics for these operations
>
> - Dividing a positive value by zero produces +∞.
> - Dividing a negative value by zero produces −∞.
>
> [...]
>
> In other words, multiplying or dividing with 0⁻ follows standard sign rules

Can you also please tell me if there is any other difference between *convert a string to a number* and JS `Number()`, please?



Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/7472 using your GitHub account


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Received on Thursday, 7 July 2022 19:26:29 UTC