Вот кратко:
Type obj
Field o_type:String
...
Method Update() Abstract
Method Destroy() Abstract
End Type
Type Grass Extends obj
Function Create()
Local NewGrass:Grass = New Grass
NewGrass.o_type="Grass"
End Function
...
Method destroy()
obj_list.remove(Self)
GCCollect()
End Method
...
End Type
Type Player Extends obj
...
Method Update()
...
For A = EachIn obj_list
...
If (A.o_type="Grass") Then A.destroy()
...
Next
...
End Method
...
End Type