Differences

This shows you the differences between two versions of the page.

--- at:tutorial:objects [2007/07/02 12:43] – jorge
+++ at:tutorial:objects [2007/07/02 13:12] – jorge
@@ Line 49: / Line 49: @@
 Every object understands the message ''new'', which creates a clone (a shallow copy) of the receiver object and initializes the clone by invoking its ''init'' method with the arguments that were passed to new (''aX'' and ''aY'' in the example of the ''point'' object). Hence, the ''init'' method plays the role of “constructor” for AmbientTalk objects. AmbientTalk’s object instantiation protocol closely corresponds to class instantiation in class-based languages, except that the new object is a clone of an existing object, rather than an empty object allocated from a class.
-AmbientTalk also provides a ''clone'' language contsruct which only creates a clone of the receiver object without calling the ''init'' method.
+AmbientTalk also provides a ''clone'' language contsruct which only creates a clone of the receiver object without calling the ''init'' method (as a matter of fact the ''new'' message desribed above does nothing more but invoking this construct and the ''init'' method subsequently).
 <code>
@@ Line 100: / Line 100: @@
 </code>
-===== First-class Delegation =====
+===== First-class delegation =====
+AmbientTalk provides an explicit delegation operator ''^'' as shown in the code below.
+<code>
+> def Point3D := extend: Point with: {
+    def z := 0;
+    def init(anX, aY, aZ) {
+      super^init(anX, aY);
+      z := aZ;
+    }
+  }
+</code>
 ===== Encapsulation =====