Ambient-Oriented Programming

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at:tutorial:objects [2007/06/29 13:06] – jorgeat:tutorial:objects [2007/06/29 13:27] – jorge
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 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. 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.
  
-===== Delegation and Dynamic Inheritance ===== +===== Delegation and Cloning ===== 
-AmbientTalk features object inheritance or delegation. By means of delegation, an object can reuse and extend the defintion of another establishing a child-parent relationship. We identify two kinds of delegation relationships: **IS-A** and **SHARE-A**, embodied by the ''extend: with:'' and ''share: with:'' language constructs respectively.+AmbientTalk features object inheritance or delegation. By means of delegation, an object can reuse and extend the defintion of another establishing a child-parent relationship. We identify two kinds of delegation relationships: **IS-A** and **SHARE-A**. These relationships define two different semantics for clonning child objects. Whereas clonning a **IS-A** child also clones its parent, **SHARE-A** child shares the parent of the cloned object.
  
-The following code shows how to extend objects with a **IS-A** relationship.+The following code shows how to extend objects with a **IS-A** relationship. It uses the ''extend: with:'' language construct.
  
 <code> <code>
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 </code> </code>
  
-The following code shows how to extend objects with a **SHARE-A** relationship.+The following code shows how to extend objects with a **SHARE-A** relationship. It uses the ''share: with:'' language construct.
  
 <code> <code>
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-These relationships defines two different semantics for clonning child objects +===== Delegation and Dynamic Inheritance =====
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- in the way  +
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-. While both relationships  +
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- Extending an object with a **is-a** relationship  +
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-===== Delegation and cloning =====+
  
 ===== First-class Delegation ===== ===== First-class Delegation =====
at/tutorial/objects.txt · Last modified: 2013/05/17 20:23 by tvcutsem