edu.vub.at.objects.mirrors
Class NativeClosure

java.lang.Object
  edu.vub.at.objects.natives.NATNil
      edu.vub.at.objects.natives.NATByRef
          edu.vub.at.objects.natives.NATClosure
              edu.vub.at.objects.mirrors.NativeClosure

All Implemented Interfaces:

ATAbstractGrammar, ATClosure, ATConversions, ATExpression, ATNil, ATObject, ATStatement, java.io.Serializable

public class NativeClosure

extends NATClosure

A NativeClosure is a wrapper class for a piece of Java code. The Java code is presented to the AmbientTalk system as a closure. A NativeClosure is represented as follows: - Its encapsulating method is a 'dummy' NativeMethod ATMethod, with the following properties: - name = "nativelambda" (to distinguish it from 'ordinary' lambdas) - arguments = [ \@args ] (it takes an arbitrary number of arguments) - body = "Native implementation in {class}" (a string telling an inspector that this closure is natively implemented in the given Java class) - applying a nativelambda directly (without going through this NativeClosure) results in an error - Its enclosed context consists of a triple (obj, obj, obj.super), where 'obj' is the Java object (implementing ATObject) that created this NativeClosure. The method and context fields of a NativeClosure are lazily generated on demand for efficiency reasons. Most of the time, a NativeClosure will not be introspected, but only applied. A NativeClosure can be used in two ways by Java code: 1) As a generator for anonymous classes to generate 'anonymous lambdas': new NativeClosure(this) { public ATObject meta_apply(ATTable args) throws NATException { ... } } 2) As a wrapper for an already existing NativeMethod: new NativeClosure(this, aJavaMethod);

Author:

tvc

See Also:

Serialized Form

Nested Class Summary

Nested classes inherited from class edu.vub.at.objects.natives.NATClosure

Field Summary

protected ATObject

scope_

Fields inherited from class edu.vub.at.objects.natives.NATClosure

context_, method_

Fields inherited from class edu.vub.at.objects.natives.NATNil

_INSTANCE_

Constructor Summary

NativeClosure(ATObject scope)
Create a new NativeClosure where meta_apply will be overridden by anonymous subclasses.

NativeClosure(ATObject scope, NativeMethod meth)
Create a new NativeClosure where meta_apply will invoke the given Java Method.

Method Summary

ATObject	base_apply(ATTable arguments) Apply the NativeClosure, which either gives rise to executing a native piece of code supplied by an anonymous subclass, or executes the wrapped NativeMethod.
ATObject	base_applyInScope(ATTable args, ATObject scope) A NativeClosure can also be directed to execute its wrapped NativeMethod in an externally specified scope.
ATContext	base_getContext() Overridden to allow for lazy instantiation of the context.
ATMethod	base_getMethod() Overridden to allow for lazy instantiation of the method.
void	checkArity(ATTable args, int required)
ATObject	get(ATTable args, int n) Auxiliary method to more easily extract arguments from an ATTable
boolean	getBln(ATTable args, int n)
double	getFrc(ATTable args, int n)
int	getNbr(ATTable args, int n)
java.lang.Object[]	getTab(ATTable args, int n)
java.lang.String	getTxt(ATTable args, int n)
NATText	meta_print() Prints out the object in a human-readable way.

Methods inherited from class edu.vub.at.objects.natives.NATClosure

base_asClosure, base_escape, base_isClosure, base_whileTrue_, meta_getStripes

Methods inherited from class edu.vub.at.objects.natives.NATByRef

meta_pass, meta_resolve

Methods inherited from class edu.vub.at.objects.natives.NATNil

asAmbientTalkObject, asJavaClassUnderSymbiosis, asJavaObjectUnderSymbiosis, asNativeBoolean, asNativeException, asNativeFarReference, asNativeFraction, asNativeNumber, asNativeNumeric, asNativeTable, asNativeText, base__opeql__opeql_, base_asActorMirror, base_asAsyncMessage, base_asBegin, base_asBoolean, base_asDefinition, base_asExpression, base_asFarReference, base_asField, base_asHandler, base_asMessage, base_asMessageCreation, base_asMethod, base_asMirror, base_asNumber, base_asSplice, base_asStatement, base_asStripe, base_asSymbol, base_asTable, base_asUnquoteSplice, base_asVariableAssignment, base_init, base_isBoolean, base_isCallFrame, base_isFarReference, base_isMessageCreation, base_isMethod, base_isMirror, base_isSplice, base_isStripe, base_isSymbol, base_isTable, base_isUnquoteSplice, base_isVariableAssignment, base_new, createChild, equals, isAmbientTalkObject, isJavaObjectUnderSymbiosis, isNativeBoolean, isNativeField, isNativeText, meta_addField, meta_addMethod, meta_assignField, meta_assignVariable, meta_clone, meta_defineField, meta_doesNotUnderstand, meta_eval, meta_extend, meta_getDynamicParent, meta_getLexicalParent, meta_grabField, meta_grabMethod, meta_invoke, meta_isCloneOf, meta_isRelatedTo, meta_isStripedWith, meta_listFields, meta_listMethods, meta_lookup, meta_newInstance, meta_quote, meta_receive, meta_respondsTo, meta_select, meta_send, meta_share, readResolve, toString, writeReplace

Methods inherited from class java.lang.Object

clone, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface edu.vub.at.objects.ATObject

base__opeql__opeql_, base_init, base_new, meta_addField, meta_addMethod, meta_assignField, meta_assignVariable, meta_clone, meta_defineField, meta_doesNotUnderstand, meta_eval, meta_extend, meta_getDynamicParent, meta_getLexicalParent, meta_grabField, meta_grabMethod, meta_invoke, meta_isCloneOf, meta_isRelatedTo, meta_isStripedWith, meta_listFields, meta_listMethods, meta_lookup, meta_newInstance, meta_pass, meta_quote, meta_receive, meta_resolve, meta_respondsTo, meta_select, meta_send, meta_share

Methods inherited from interface edu.vub.at.objects.coercion.ATConversions

asAmbientTalkObject, asJavaClassUnderSymbiosis, asJavaObjectUnderSymbiosis, asNativeBoolean, asNativeException, asNativeFarReference, asNativeFraction, asNativeNumber, asNativeNumeric, asNativeTable, asNativeText, base_asActorMirror, base_asAsyncMessage, base_asBegin, base_asBoolean, base_asDefinition, base_asExpression, base_asFarReference, base_asField, base_asHandler, base_asMessage, base_asMessageCreation, base_asMethod, base_asMirror, base_asNumber, base_asSplice, base_asStatement, base_asStripe, base_asSymbol, base_asTable, base_asUnquoteSplice, base_asVariableAssignment, base_isBoolean, base_isCallFrame, base_isFarReference, base_isMessageCreation, base_isMethod, base_isMirror, base_isSplice, base_isStripe, base_isSymbol, base_isTable, base_isUnquoteSplice, base_isVariableAssignment, isAmbientTalkObject, isJavaObjectUnderSymbiosis, isNativeBoolean, isNativeField, isNativeText

Field Detail

scope_

protected final ATObject scope_

Constructor Detail

NativeClosure

public NativeClosure(ATObject scope)

Create a new NativeClosure where meta_apply will be overridden by anonymous subclasses.

Parameters:

scope - the object creating this NativeClosure.

NativeClosure

public NativeClosure(ATObject scope,
                     NativeMethod meth)

Create a new NativeClosure where meta_apply will invoke the given Java Method.

Parameters:

scope - the object that should be used as a receiver for the corresponding method.

meth - a presumably native method

Method Detail

base_getMethod

public ATMethod base_getMethod()

Overridden to allow for lazy instantiation of the method. If receiver is an anonymous NativeClosure, an 'anonymous' NativeMethod is returned.

Specified by:

base_getMethod in interface ATClosure

Overrides:

base_getMethod in class NATClosure

Returns:

a NativeMethod wrapped by this NativeClosure.

base_getContext

public ATContext base_getContext()
                          throws InterpreterException

Overridden to allow for lazy instantiation of the context. A 'default' context is lazily constructed and returned.

Specified by:

base_getContext in interface ATClosure

Overrides:

base_getContext in class NATClosure

Throws:

InterpreterException

base_apply

public ATObject base_apply(ATTable arguments)
                    throws InterpreterException

Apply the NativeClosure, which either gives rise to executing a native piece of code supplied by an anonymous subclass, or executes the wrapped NativeMethod.

Specified by:

base_apply in interface ATClosure

Overrides:

base_apply in class NATClosure

Throws:

InterpreterException

base_applyInScope

public ATObject base_applyInScope(ATTable args,
                                  ATObject scope)
                           throws InterpreterException

A NativeClosure can also be directed to execute its wrapped NativeMethod in an externally specified scope. Of course, for native calls or symbiotic calls, the call will only succeed if the externally specified object is of the correct native type.

Specified by:

base_applyInScope in interface ATClosure

Overrides:

base_applyInScope in class NATClosure

Throws:

InterpreterException

meta_print

public NATText meta_print()
                   throws InterpreterException

Description copied from interface: ATObject

Prints out the object in a human-readable way.

Specified by:

meta_print in interface ATObject

Overrides:

meta_print in class NATClosure

Throws:

InterpreterException

get

public ATObject get(ATTable args,
                    int n)
             throws InterpreterException

Auxiliary method to more easily extract arguments from an ATTable

Throws:

InterpreterException

getNbr

public int getNbr(ATTable args,
                  int n)
           throws InterpreterException

Throws:

InterpreterException

getFrc

public double getFrc(ATTable args,
                     int n)
              throws InterpreterException

Throws:

InterpreterException

getTxt

public java.lang.String getTxt(ATTable args,
                               int n)
                        throws InterpreterException

Throws:

InterpreterException

getBln

public boolean getBln(ATTable args,
                      int n)
               throws InterpreterException

Throws:

InterpreterException

getTab

public java.lang.Object[] getTab(ATTable args,
                                 int n)
                          throws InterpreterException

Throws:

InterpreterException

checkArity

public void checkArity(ATTable args,
                       int required)
                throws InterpreterException

Throws:

InterpreterException