edu.vub.at.objects.natives
Class NATClosureMethod

java.lang.Object
  edu.vub.at.objects.natives.NATNil
      edu.vub.at.objects.natives.NATByRef
          edu.vub.at.objects.natives.NATClosureMethod

All Implemented Interfaces:

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

public final class NATClosureMethod

extends NATByRef

implements ATMethod

A 'closure method' is literally a function that sits in between of a full closure and a method. It is a method that captures only its lexical scope of definition, but not the value of 'self' and 'super' which are active at that time. When invoked, the method is evaluated in its lexical scope, but with the values of 'self' and 'super' equal to those given to it at method invocation time. Closure methods are used to implement 'externally added' methods to objects. In such cases, the external methods can only access their own surrounding lexical scope (and not that of the actual object to which they are added), but their values for 'self' and 'super' will act as if the method was actually defined within the object itself. See the description of the ATDefExternalMethod interface for more information.

Author:

tvcutsem

See Also:

Serialized Form

Field Summary

private ATObject	lexicalScope_
private ATMethod	method_

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

_INSTANCE_

Constructor Summary

NATClosureMethod(ATObject scope, ATMethod method)

Method Summary

ATObject	base_apply(ATTable arguments, ATContext ctx) A closure method application acts exactly like a regular direct method application, except that the given lexical scope is disregarded and replaced by the lexical scope encapsulated by the closure method.
ATObject	base_applyInScope(ATTable arguments, ATContext ctx) Applies the method to the given arguments in the given context.
ATMethod	base_asMethod()
ATBegin	base_getBodyExpression() Structural access to the body of the method.
ATSymbol	base_getName() Structural access to the name of the method.
ATTable	base_getParameters() Structural access to the parameter list of the method, which is normally a table of symbols.
boolean	base_isMethod()
ATTable	meta_getStripes() Returns the stripes of this object.
NATText	meta_print() Prints out the object in a human-readable way.

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_asClosure, base_asDefinition, base_asExpression, base_asFarReference, base_asField, base_asHandler, base_asMessage, base_asMessageCreation, 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_isClosure, base_isFarReference, base_isMessageCreation, 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_asClosure, base_asDefinition, base_asExpression, base_asFarReference, base_asField, base_asHandler, base_asMessage, base_asMessageCreation, base_asMirror, base_asNumber, base_asSplice, base_asStatement, base_asStripe, base_asSymbol, base_asTable, base_asUnquoteSplice, base_asVariableAssignment, base_isBoolean, base_isCallFrame, base_isClosure, base_isFarReference, base_isMessageCreation, base_isMirror, base_isSplice, base_isStripe, base_isSymbol, base_isTable, base_isUnquoteSplice, base_isVariableAssignment, isAmbientTalkObject, isJavaObjectUnderSymbiosis, isNativeBoolean, isNativeField, isNativeText

Field Detail

lexicalScope_

private final ATObject lexicalScope_

method_

private final ATMethod method_

Constructor Detail

NATClosureMethod

public NATClosureMethod(ATObject scope,
                        ATMethod method)
                 throws InterpreterException

Method Detail

base_apply

public ATObject base_apply(ATTable arguments,
                           ATContext ctx)
                    throws InterpreterException

A closure method application acts exactly like a regular direct method application, except that the given lexical scope is disregarded and replaced by the lexical scope encapsulated by the closure method. The bindings for 'self' and 'super' remain intact. Closure methods are a result of external method definitions.

Specified by:

base_apply in interface ATMethod

Parameters:

arguments - the evaluated actual arguments

ctx - the context whose 'self' binding will be used during the execution of the method. The lexical scope, however, will be replaced by the closure method's own lexical scope. A call frame will be inserted into this lexical scope before executing the method body. To ensure that 'super' points to the parent of the actual 'self' and not the parent of the object performing the external method definition, a 'super' field is added to the call frame shadowing the defining object's 'super' field.

Returns:

the value of evaluating the function body

Throws:

InterpreterException

base_applyInScope

public ATObject base_applyInScope(ATTable arguments,
                                  ATContext ctx)
                           throws InterpreterException

Description copied from interface: ATMethod

Applies the method to the given arguments in the given context. The context is usually supplied by a closure and is necessary in order to pair a method with its current receiver (its 'self') The method will use the given context 'as-is', and will *not* insert an additional call frame.

Specified by:

base_applyInScope in interface ATMethod

Parameters:

arguments - the actual arguments, already eagerly evaluated

ctx - the context in which to evaluate the method body, to be used without inserting a call frame

Returns:

the value of evaluating the method body in the given context

Throws:

InterpreterException

base_getBodyExpression

public ATBegin base_getBodyExpression()
                               throws InterpreterException

Description copied from interface: ATMethod

Structural access to the body of the method.

Specified by:

base_getBodyExpression in interface ATMethod

Throws:

InterpreterException

base_getName

public ATSymbol base_getName()
                      throws InterpreterException

Description copied from interface: ATMethod

Structural access to the name of the method. Note that all methods (defined using def name( ...args... ) { ... } of def foo: arg bar: arg { ... }) retain the name with which they were first bound. Literal blocks which may be created outside of a definition are implicitly named 'lambda'.

Specified by:

base_getName in interface ATMethod

Throws:

InterpreterException

base_getParameters

public ATTable base_getParameters()
                           throws InterpreterException

Description copied from interface: ATMethod

Structural access to the parameter list of the method, which is normally a table of symbols.

Specified by:

base_getParameters in interface ATMethod

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 NATNil

Throws:

InterpreterException

base_asMethod

public ATMethod base_asMethod()
                       throws XTypeMismatch

Specified by:

base_asMethod in interface ATConversions

Overrides:

base_asMethod in class NATNil

Throws:

XTypeMismatch

base_isMethod

public boolean base_isMethod()

Specified by:

base_isMethod in interface ATConversions

Overrides:

base_isMethod in class NATNil

meta_getStripes

public ATTable meta_getStripes()
                        throws InterpreterException

Description copied from interface: ATObject

Returns the stripes of this object. Note that only the stripes that were attached directly to this object are returned, not all of the parent's stripes as well.

Specified by:

meta_getStripes in interface ATObject

Overrides:

meta_getStripes in class NATNil

Throws:

InterpreterException