(class-of ob)
  ob: an obj or an rdata
  returns a class or a sym
F

Returns the class of an object or RData.

For an object, its class is identified using a reference to a class object. For an RData, its class is identified using a symbol.

(prn (class-of obj)) ; prints #<class:Rect>
(prn (class-of rdata)) ; prints Sprite
is?
class-name