Another update from ingydotnet^djgoku

Task/Polymorphic-copy/Forth/polymorphic-copy-2.fth

@@ -0,0 +1,25 @@
+include FMS-SI.f
+
+:class T
+ ivar container  \ can contain an object of any type
+ :m put ( obj -- ) container ! ;m
+ :m init: self self put ;m \ initially container holds self
+ :m print ." class is T" ;m
+ :m print-container container @ print ;m
+;class
+
+:class S <super T    \ subclass S from T
+ :m print ." class is S" ;m \ override T's print method
+;class
+
+: ecopy {: obj1 -- obj2 :} \ make an exact copy of obj
+  obj1 dup >class dfa @
+  obj1 heap: dup >r swap move r> ;
+
+T obj-t  \ instantiate a T object
+obj-t print-container \ class is T
+
+S obj-s  \ instantiate an S object
+obj-s ecopy obj-t put  \ make an exact copy of S object and store in T object
+
+obj-t print-container \ class is S