(class-of ob)
  ob: an obj or an rdata
  returns a class, a sym, or #n
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 RClass is identified using a symbol, or nil if it has no RClass.

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