New rule: function-operator-space about stylelint

[davidtheclark]

Does anybody know about operators other than + - * and / that we'd need to check?

[MoOx]

Not sure there is others. (Not for calc() at least)

[jeddy3]

Same, don't know of any others. http://www.w3.org/TR/css3-values/#calc

[davidtheclark]

@MoOx raised a point here: #62 (comment)

But for function-operator-space it's a bit more tricky since you can have +10% value (see color function spec).

Yeah, so the whitespace is significant to the language not just the style around + and -, cf. http://www.w3.org/TR/css3-values/#calc-syntax. (And for the +10% example cf. http://dev.w3.org/csswg/css-color/) Does that mean we should restrict this rule to calc() only? calc-operator-space?

[MoOx]

calc-operator-space looks like an edge case, maybe we can postpone that.

[davidtheclark]

Unsure where this conversation left off. Let's clarify: Do we want calc-operator-space? It seems like the only situation we're aware of where function-operator-space would actually apply.

I use calc() enough in my stylesheets that I think that would be a valuable rule.

[MoOx]

If you want to do it, go :)
I was just thinking it can be low priority. Do whatever you need ;)

[davidtheclark]

OK, got it.