at:tutorial:symbiosis
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at:tutorial:symbiosis [2007/07/05 09:47] – jdedecker | at:tutorial:symbiosis [2008/10/22 16:52] – updated tvcutsem | ||
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- | < | ||
====== Symbiosis with Java ====== | ====== Symbiosis with Java ====== | ||
- | AmbientTalk is fully implemented in Java and runs on top of the JVM. Java provides an extensive class library that can be accessed from within AmbientTalk. | + | AmbientTalk is entirely |
- | The reverse, | + | The reverse, |
- | This chapter explains how both sides of this symbiotic relationship between Java and AmbientTalk can be leveraged. The goal of this symbiotic relationship is to complement the advantages of both languages and to alleviate their disadvantages. | + | This chapter explains how to program using this "symbiotic relationship" |
===== Symbiosis Architecture ===== | ===== Symbiosis Architecture ===== | ||
+ | |||
AmbientTalk has been implemented in Java. Because of this, Java plays two roles: it is both a symbiont language and the implementation language of AmbientTalk (and hence of the linguistic symbiosis itself). The figure below illustrates the different objects that play a part in the AmbientTalk/ | AmbientTalk has been implemented in Java. Because of this, Java plays two roles: it is both a symbiont language and the implementation language of AmbientTalk (and hence of the linguistic symbiosis itself). The figure below illustrates the different objects that play a part in the AmbientTalk/ | ||
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If the Java method is overloaded based on arity (i.e. each overloaded method takes a different number of arguments), the number of arguments in the AmbientTalk invocation can be used to identify a unique Java method. Hence, overloading based on arity does not require special attention. If the Java method is overloaded based solely on argument types, the interpreter may derive that the actual arguments can only be converted from AmbientTalk to the appropriate Java types for one of the matching overloaded signatures. Again, if only one match remains, the unique match is invoked. In the remaining case in which the actual AmbientTalk arguments satisfy more than one overloaded method signature, the symbiotic invocation fails. It is then the AmbientTalk programmer' | If the Java method is overloaded based on arity (i.e. each overloaded method takes a different number of arguments), the number of arguments in the AmbientTalk invocation can be used to identify a unique Java method. Hence, overloading based on arity does not require special attention. If the Java method is overloaded based solely on argument types, the interpreter may derive that the actual arguments can only be converted from AmbientTalk to the appropriate Java types for one of the matching overloaded signatures. Again, if only one match remains, the unique match is invoked. In the remaining case in which the actual AmbientTalk arguments satisfy more than one overloaded method signature, the symbiotic invocation fails. It is then the AmbientTalk programmer' | ||
- | Selection of the correct overloaded method is done using the **cast** method. | + | Selection of the correct overloaded method is done using the '' |
< | < | ||
- | >def remove := aVector.remove | + | >def remove := aVector.&remove |
>>< | >>< | ||
> | > | ||
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def showSymbiosis() { | def showSymbiosis() { | ||
- | def javaDemo := SymbiosisDemo.new(); | + | |
- | def atObject := object: { | + | |
- | def ping() { | + | def ping() { |
- | system.println(" | + | system.println(" |
- | javaDemo.run2(self); | + | javaDemo.run2(self); |
- | }; | + | }; |
- | def pong() { | + | def pong() { |
- | system.println(" | + | system.println(" |
- | 42 | + | 42 |
- | } | + | } |
- | }; | + | }; |
- | javaDemo.run(atObject); | + | |
}; | }; | ||
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If Java invokes a method declared in an interface with an overloaded method signature, all overloaded invocations are transformed into the same method invocation on the AmbientTalk object. In other words, the AmbientTalk object does not take the types into consideration. However, if the Java method is overloaded based on arity, the AmbientTalk programmer can take this into account in the parameter list of the corresponding AmbientTalk method, by means of a variable-argument list or optional parameters. Otherwise, the Java invocation may fail because of an arity mismatch. | If Java invokes a method declared in an interface with an overloaded method signature, all overloaded invocations are transformed into the same method invocation on the AmbientTalk object. In other words, the AmbientTalk object does not take the types into consideration. However, if the Java method is overloaded based on arity, the AmbientTalk programmer can take this into account in the parameter list of the corresponding AmbientTalk method, by means of a variable-argument list or optional parameters. Otherwise, the Java invocation may fail because of an arity mismatch. | ||
+ | |||
+ | < | ||
+ | >def test := / | ||
+ | >>< | ||
+ | > | ||
+ | ping! | ||
+ | pong! | ||
+ | >>42 | ||
+ | </ | ||
+ | |||
+ | ==== Starting an AmbientTalk interpreter from Java ==== | ||
+ | So far, the examples have illustrated how to reuse Java code from within AmbientTalk. They have shown how to access Java classes, instantiate them and invoke methods on the resulting objects. Moreover, | ||
+ | |||
+ | Embedding AmbientTalk in an application, | ||
+ | |||
+ | < | ||
+ | EmbeddedAmbientTalk vm = new EmbeddedAmbientTalk(); | ||
+ | vm.initialize( | ||
+ | NATParser.parse( | ||
+ | initFile.getName(), | ||
+ | Evaluator.loadContentOfFile(initFile)), | ||
+ | new SharedActorField[] { | ||
+ | vm.computeSystemObject(arguments), | ||
+ | vm.computeWorkingDirectory(), | ||
+ | vm.computeObjectPath(objectPath) }, | ||
+ | " | ||
+ | </ | ||
+ | The code excerpt also illustrates that the EmbeddableAmbientTalk class provides methods to create definitions for fields such as '' | ||
+ | |||
+ | Once the virtual machine is properly initialized, | ||
+ | |||
+ | < | ||
+ | public interface Controller { | ||
+ | public void executeEvent(ApplicationEvent evt); | ||
+ | public void executeEventWithoutUndo(ApplicationEvent evt); | ||
+ | public void undo(); | ||
+ | } | ||
+ | ... | ||
+ | private Controller controller = | ||
+ | (Controller) vm.evalAndWrap( | ||
+ | Evaluator.loadContentsOfFile(" | ||
+ | Controller.class); | ||
+ | </ | ||
+ | |||
+ | The corresponding AmbientTalk code should then return an object which implements the three methods to modify the model, and can be used to detect other reachable controllers with which it can exchange ApplicationEvents. | ||
+ | |||
+ | < | ||
+ | When starting an AmbientTalk virtual machine from a Java application, | ||
+ | </ |
at/tutorial/symbiosis.txt · Last modified: 2013/05/17 20:25 by tvcutsem