from static method
Implementation
static CSSNumber? from(Object? value) {
if (value == null) return null;
if (value is CSSNumber) return value;
if (value is String) {
var f = CSSFunction.parse(value);
if (f != null) {
if (f is CSSCalc && !f.hasOperation) {
var calcNumber = CSSNumber.parse(f.a);
if (calcNumber.toString() == f.a) {
return calcNumber;
}
}
return CSSNumber.fromFunction(f);
} else {
return CSSNumber.parse(value);
}
}
return null;
}