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--- at:tutorial:reflection [2008/09/15 17:58] – rewritten tvcutsem
+++ at:tutorial:reflection [2008/11/06 15:36] – elisag
@@ Line 28: / Line 28: @@
 </code>
-The code excerpt presented above uses the mirror to //introspect// on an object and uses the ''listSlots'' meta-method. The result is a table of the slots (fields and methods) provided by this object. Notice that fields are represented as a combination of an accessor and a mutator method, conforming to the Uniform Access Principle as discussed in [[:at:tutorial:objects#uniform_access|chapter 5]]. Also note that the object has a field called ''super'', although this field was not explicitly defined. In AmbientTalk, ''super'' is defined implicitly for every object.
+The code excerpt presented above uses the mirror to //introspect// on an object and uses the ''listSlots'' meta-method. The result is a table of the slots (fields and methods) provided by this object. Notice that fields are represented as a combination of an accessor and a mutator method, conforming to the Uniform Access Principle as discussed in [[:at:tutorial:objects#uniform_access|chapter 5]]. Also note that the object has a field called ''super'', although this field was not explicitly defined. In AmbientTalk, ''super'' is defined implicitly for every object. The picture below gives an overview of the different objects involved in the actor.
+{{:at:tutorial:meta-1.jpg|:at:tutorial:meta-1.jpg}}
 The code excerpt below shows how one can add and remove slots to and from an object, and how one can explicitly access values and invoke methods upon an object, reflectively:
@@ Line 79: / Line 81: @@
-A complete overview of all meta-operations will be presented near the end of this chapter and can also be found in the [[http://prog.vub.ac.be/amop/at2langref/edu/vub/at/objects/MirrorRoot.html|language reference]].
+A complete overview of all meta-operations will be presented near the end of this chapter.
 ===== Mirages =====
@@ Line 119: / Line 121: @@
 </code>
-In the code above, the closure passed to ''mirroredBy:'' is a //mirror construction closure//. This closure is applied to a new, empty mirage object and it is expected that it returns a new mirror that reflects upon this mirage. When the mirror is constructed, the object initialization closure is executed.
+In the code above, the closure passed to ''mirroredBy:'' is a //mirror construction closure//. This closure is applied to a new, empty mirage object and it is expected that it returns a new mirror that reflects upon this mirage. When the mirror is constructed, the object initialization closure is executed. The picture below gives an overview of the different objects involved in the actor.
+{{:at:tutorial:meta-2.jpg|:at:tutorial:meta-2.jpg}}
 When invoking the method ''m'' on the mirage, ''invoke'' will be invoked on the tracing mirror, causing the following behaviour:
@@ Line 133: / Line 138: @@
 ===== The Metaobject Protocol =====
-The Meta-Object Protocol of AmbientTalk can be divided into a series of independent protocols. Whereas the full semantics and signature of the meta-methods can be found in the [[http://prog.vub.ac.be/amop/at2langref/edu/vub/at/objects/Object.html|language reference]], this section provides an overview of the various protocols.
+The Meta-Object Protocol of AmbientTalk can be divided into a series of independent protocols. Whereas the full semantics and signature of the meta-methods can be found in the [[http://prog.vub.ac.be/amop/at2langref/edu/vub/at/objects/MirrorRoot.html|language reference]], this section provides an overview of the various protocols.
 The **Message Passing Protocol** consists of methods to deal with both synchronous and asynchronous message sending. It provides necessary hooks to intercept both the reception of asynchronous messages and the invocation of synchronous messages. Moreover, it provides a hook to intercept asynchronous messages being sent by the object, allowing the object to add additional metadata to the message. The ''invoke'' meta-method illustrated above is an example of a method belonging to this protocol.
@@ Line 141: / Line 146: @@
 The **Slot Access and Modification Protocol** consists of operations which allow trapping both dynamic access and modification to slots. For instance, ''o.x'' can be intercepted using the ''invokeField'' meta-method, while ''o.x := 5'' is trapped using ''invoke'' where the selector will equal ''x:=''.
-The **Structural Access Protocol** consists of operations used list all available slots, get access to a first-class slot representation and to add new slots to an existing object. The ''listMethods'' and ''listFields'' meta-methods used in previous examples are elements of this protocol.
+The **Structural Access Protocol** consists of operations used list all available slots, get access to a first-class slot representation and to add new slots to an existing object. The ''listSlots'' meta-method used in previous example is a member of this protocol.
 The **Instantiation Protocol** consists of the ''clone'' and ''newInstance'' methods, which are implictly called when using base-level code of the form ''clone: object'' and ''object.new(@args)'' respectively. In the default implementation, ''newInstance'' calls ''clone()'' to create a clone of the current object, and subsequently invokes the base-level ''init'' method with the supplied arguments on the cloned object.