Initial data commit

Task/Polymorphic-copy/Nim/polymorphic-copy.nim

@@ -0,0 +1,37 @@
+type
+  T = ref object of RootObj
+    myValue: string
+  S1 = ref object of T
+  S2 = ref object of T
+
+method speak(x: T) {.base.} = echo "T Hello ", x.myValue
+method speak(x: S1) = echo "S1 Meow ", x.myValue
+method speak(x: S2) = echo "S2 Woof ", x.myValue
+
+echo "creating initial objects of types S1, S2, and T."
+var a = S1(myValue: "Green")
+a.speak
+var b = S2(myValue: "Blue")
+b.speak
+var u = T(myValue: "Blue")
+u.speak
+
+echo "Making copy of a as u; colors and types should match."
+u.deepCopy(a)
+u.speak
+a.speak
+
+echo "Assigning new color to u; A's color should be unchanged."
+u.myValue = "Orange"
+u.speak
+a.speak
+
+echo "Assigning u to reference same object as b; colors and types should match."
+u = b
+u.speak
+b.speak
+
+echo "Assigning new color to u. Since u,b reference the same object, b's color changes as well."
+u.myValue = "Yellow"
+u.speak
+b.speak