calc() doesn't support dividing an expression

[upsuper]

calc(50px / 2) works, but calc(50px / (1 + 1)) doesn't work.

[Manishearth]

Division is implemented as 1 / multiplication, which we probably shouldn't do.

[nox]

Do we want to keep CalcSumNode and CalcProductNode, or do we want to do a proper AST such as:

enum CalcNode {
    Value(CalcValueNode),
    BinOp(CalcValueNode, BinOp, CalcValueNode),
}

enum BinOp {
    Add, Mul, Div
}

[nox]

@upsuper https://drafts.csswg.org/css-values/#calc-syntax says / should only be followed by <number>. Do we really want to support 50px / (1 + 1)?

[nox]

Seems like the spec is wrong on this, both Firefox and WebKit don't mind the addition.

[nox]

w3c/csswg-drafts#1241

[upsuper]

Yeah, dbaron is right that we should support it, especially given that Gecko already supports it, and CSSWG is going to expand that to support even more powerful expression.

[KiChjang]

The draft has been updated with an extended syntax to support different kinds of expressions.

Taking a look at this.

[KiChjang]

Blocked on #16728.

[wafflespeanut]

#16728 seems to fix this.