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at:tutorial:actors [2008/03/13 16:49] – added tvcutsemat:tutorial:actors [2008/06/18 19:22] – install tvcutsem
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 Some operations, such as creating and sending asynchronous messages are useful to reify at the //actor level//. With such a reification, the programmer could override the way messages are sent by any object from within an actor. The mirror on an actor that reifies these operations is bound to the ''actor'' variable, defined at top-level. Evaluating ''actor'' returns the mirror on the current actor. It defines operations such as ''createMessage'' and ''send'' which can be explicitly invoked, or even overridden by the programmer. Some operations, such as creating and sending asynchronous messages are useful to reify at the //actor level//. With such a reification, the programmer could override the way messages are sent by any object from within an actor. The mirror on an actor that reifies these operations is bound to the ''actor'' variable, defined at top-level. Evaluating ''actor'' returns the mirror on the current actor. It defines operations such as ''createMessage'' and ''send'' which can be explicitly invoked, or even overridden by the programmer.
  
-Overriding the actor's metaobject protocol can be done by //installing// a new protocol object. This is done by invoking the ''install:'' method on ''actor''. The following code installs a new MOP that logs any messages sent by any object in the current actor:+Overriding the actor's metaobject protocol can be done by //installing// a new protocol object. This is done by invoking the ''replaceMirror:'' method on ''actor''. The following code installs a new MOP that logs any messages sent by any object in the current actor:
  
 <code> <code>
-def oldmirror := actor.install: (extend: actor with: {+def oldmirror := actor.replaceMirror: (extend: actor with: {
   def send(msg) {   def send(msg) {
     log(msg);     log(msg);
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 </code> </code>
  
-Notice that, in this example, the new metaobject protocol is an extension of the old protocol. This enables it to invoke its parent's behaviour simply by means of a super-send. Note also that the ''install:'' primitive returns the previously installed mirror. This is useful for when an actor mirror should only temporarily be installed. The old mirror can later be re-installed.+Notice that, in this example, the new metaobject protocol is an extension of the old protocol. This enables it to invoke its parent's behaviour simply by means of a super-send. Note also that the ''replaceMirror:'' primitive returns the previously installed mirror. This is useful for when an actor mirror should only temporarily be installed. The old mirror can later be re-installed.
  
 <note> <note>
at/tutorial/actors.txt · Last modified: 2020/02/05 21:26 by elisag