func isEmpty(v, t *js.Object) bool {
switch t.Get("kind").Int() {
case boolKind:
return !v.Bool()
case int8Kind, int16Kind, int32Kind, intKind, uint8Kind, uint16Kind, uint32Kind, uintKind:
return v.Int() == 0
case int64Kind, uint64Kind:
return v.Int64() == 0
case float32Kind, float64Kind:
return v.Float() == 0
case arrayKind, sliceKind, stringKind:
return v.Length() == 0
case ptrKind:
return v == t.Get("nil")
case interfaceKind:
if v.Get("$val") == js.Undefined {
return true
}
return isEmpty(v.Get("$val"), v.Get("constructor"))
case mapKind:
return js.Global.Get("Object").Call("keys", v).Length() == 0
}
return false
}
//LinearF calls the scale to interpolate a value into its range and returns
//the results as a float. If the extractor function is specified, it should
//pull the floating point input value out of the provided object.
func (self *linearScaleImpl) LinearF(obj js.Object, fn ExtractorFuncF) float64 {
if fn != nil {
return self.obj.Invoke(fn(obj)).Float()
}
return self.obj.Invoke(obj.Float()).Float()
}