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package javax.lang.model.util;
import javax.lang.model.element.*;
import static javax.lang.model.element.ElementKind.*;
import javax.annotation.processing.SupportedSourceVersion;
import static javax.lang.model.SourceVersion.*;
import javax.lang.model.SourceVersion;
/**
* A visitor of program elements based on their {@linkplain
* ElementKind kind} with default behavior appropriate for the {@link
* SourceVersion#RELEASE_6 RELEASE_6} source version. For {@linkplain
* Element elements} <tt><i>XYZ</i></tt> that may have more than one
* kind, the <tt>visit<i>XYZ</i></tt> methods in this class delegate
* to the <tt>visit<i>XYZKind</i></tt> method corresponding to the
* first argument's kind. The <tt>visit<i>XYZKind</i></tt> methods
* call {@link #defaultAction defaultAction}, passing their arguments
* to {@code defaultAction}'s corresponding parameters.
*
* <p> Methods in this class may be overridden subject to their
* general contract. Note that annotating methods in concrete
* subclasses with {@link java.lang.Override @Override} will help
* ensure that methods are overridden as intended.
*
* <p> <b>WARNING:</b> The {@code ElementVisitor} interface
* implemented by this class may have methods added to it or the
* {@code ElementKind} {@code enum} used in this case may have
* constants added to it in the future to accommodate new, currently
* unknown, language structures added to future versions of the
* Java™ programming language. Therefore, methods whose names
* begin with {@code "visit"} may be added to this class in the
* future; to avoid incompatibilities, classes which extend this class
* should not declare any instance methods with names beginning with
* {@code "visit"}.
*
* <p>When such a new visit method is added, the default
* implementation in this class will be to call the {@link
* #visitUnknown visitUnknown} method. A new abstract element kind
* visitor class will also be introduced to correspond to the new
* language level; this visitor will have different default behavior
* for the visit method in question. When the new visitor is
* introduced, all or portions of this visitor may be deprecated.
*
* <p>Note that adding a default implementation of a new visit method
* in a visitor class will occur instead of adding a <em>default
* method</em> directly in the visitor interface since a Java SE 8
* language feature cannot be used to this version of the API since
* this version is required to be runnable on Java SE 7
* implementations. Future versions of the API that are only required
* to run on Java SE 8 and later may take advantage of default methods
* in this situation.
*
* @param <R> the return type of this visitor's methods. Use {@link
* Void} for visitors that do not need to return results.
* @param <P> the type of the additional parameter to this visitor's
* methods. Use {@code Void} for visitors that do not need an
* additional parameter.
*
* @author Joseph D. Darcy
* @author Scott Seligman
* @author Peter von der Ahé
*
* @see ElementKindVisitor7
* @see ElementKindVisitor8
* @since 1.6
*/
@SupportedSourceVersion(RELEASE_6)
public class ElementKindVisitor6<R, P>
extends SimpleElementVisitor6<R, P> {
/**
* Constructor for concrete subclasses; uses {@code null} for the
* default value.
*/
protected ElementKindVisitor6() {
super(null);
}
/**
* Constructor for concrete subclasses; uses the argument for the
* default value.
*
* @param defaultValue the value to assign to {@link #DEFAULT_VALUE}
*/
protected ElementKindVisitor6(R defaultValue) {
super(defaultValue);
}
/**
* {@inheritDoc}
*
* The element argument has kind {@code PACKAGE}.
*
* @param e {@inheritDoc}
* @param p {@inheritDoc}
* @return {@inheritDoc}
*/
@Override
public R visitPackage(PackageElement e, P p) {
assert e.getKind() == PACKAGE: "Bad kind on PackageElement";
return defaultAction(e, p);
}
/**
* Visits a type element, dispatching to the visit method for the
* specific {@linkplain ElementKind kind} of type, {@code
* ANNOTATION_TYPE}, {@code CLASS}, {@code ENUM}, or {@code
* INTERFACE}.
*
* @param e {@inheritDoc}
* @param p {@inheritDoc}
* @return the result of the kind-specific visit method
*/
@Override
public R visitType(TypeElement e, P p) {
ElementKind k = e.getKind();
switch(k) {
case ANNOTATION_TYPE:
return visitTypeAsAnnotationType(e, p);
case CLASS:
return visitTypeAsClass(e, p);
case ENUM:
return visitTypeAsEnum(e, p);
case INTERFACE:
return visitTypeAsInterface(e, p);
default:
throw new AssertionError("Bad kind " + k + " for TypeElement" + e);
}
}
/**
* Visits an {@code ANNOTATION_TYPE} type element by calling
* {@code defaultAction}.
*
* @param e the element to visit
* @param p a visitor-specified parameter
* @return the result of {@code defaultAction}
*/
public R visitTypeAsAnnotationType(TypeElement e, P p) {
return defaultAction(e, p);
}
/**
* Visits a {@code CLASS} type element by calling {@code
* defaultAction}.
*
* @param e the element to visit
* @param p a visitor-specified parameter
* @return the result of {@code defaultAction}
*/
public R visitTypeAsClass(TypeElement e, P p) {
return defaultAction(e, p);
}
/**
* Visits an {@code ENUM} type element by calling {@code
* defaultAction}.
*
* @param e the element to visit
* @param p a visitor-specified parameter
* @return the result of {@code defaultAction}
*/
public R visitTypeAsEnum(TypeElement e, P p) {
return defaultAction(e, p);
}
/**
* Visits an {@code INTERFACE} type element by calling {@code
* defaultAction}.
*.
* @param e the element to visit
* @param p a visitor-specified parameter
* @return the result of {@code defaultAction}
*/
public R visitTypeAsInterface(TypeElement e, P p) {
return defaultAction(e, p);
}
/**
* Visits a variable element, dispatching to the visit method for
* the specific {@linkplain ElementKind kind} of variable, {@code
* ENUM_CONSTANT}, {@code EXCEPTION_PARAMETER}, {@code FIELD},
* {@code LOCAL_VARIABLE}, {@code PARAMETER}, or {@code RESOURCE_VARIABLE}.
*
* @param e {@inheritDoc}
* @param p {@inheritDoc}
* @return the result of the kind-specific visit method
*/
@Override
public R visitVariable(VariableElement e, P p) {
ElementKind k = e.getKind();
switch(k) {
case ENUM_CONSTANT:
return visitVariableAsEnumConstant(e, p);
case EXCEPTION_PARAMETER:
return visitVariableAsExceptionParameter(e, p);
case FIELD:
return visitVariableAsField(e, p);
case LOCAL_VARIABLE:
return visitVariableAsLocalVariable(e, p);
case PARAMETER:
return visitVariableAsParameter(e, p);
case RESOURCE_VARIABLE:
return visitVariableAsResourceVariable(e, p);
default:
throw new AssertionError("Bad kind " + k + " for VariableElement" + e);
}
}
/**
* Visits an {@code ENUM_CONSTANT} variable element by calling
* {@code defaultAction}.
*
* @param e the element to visit
* @param p a visitor-specified parameter
* @return the result of {@code defaultAction}
*/
public R visitVariableAsEnumConstant(VariableElement e, P p) {
return defaultAction(e, p);
}
/**
* Visits an {@code EXCEPTION_PARAMETER} variable element by calling
* {@code defaultAction}.
*
* @param e the element to visit
* @param p a visitor-specified parameter
* @return the result of {@code defaultAction}
*/
public R visitVariableAsExceptionParameter(VariableElement e, P p) {
return defaultAction(e, p);
}
/**
* Visits a {@code FIELD} variable element by calling
* {@code defaultAction}.
*
* @param e the element to visit
* @param p a visitor-specified parameter
* @return the result of {@code defaultAction}
*/
public R visitVariableAsField(VariableElement e, P p) {
return defaultAction(e, p);
}
/**
* Visits a {@code LOCAL_VARIABLE} variable element by calling
* {@code defaultAction}.
*
* @param e the element to visit
* @param p a visitor-specified parameter
* @return the result of {@code defaultAction}
*/
public R visitVariableAsLocalVariable(VariableElement e, P p) {
return defaultAction(e, p);
}
/**
* Visits a {@code PARAMETER} variable element by calling
* {@code defaultAction}.
*
* @param e the element to visit
* @param p a visitor-specified parameter
* @return the result of {@code defaultAction}
*/
public R visitVariableAsParameter(VariableElement e, P p) {
return defaultAction(e, p);
}
/**
* Visits a {@code RESOURCE_VARIABLE} variable element by calling
* {@code visitUnknown}.
*
* @param e the element to visit
* @param p a visitor-specified parameter
* @return the result of {@code visitUnknown}
*
* @since 1.7
*/
public R visitVariableAsResourceVariable(VariableElement e, P p) {
return visitUnknown(e, p);
}
/**
* Visits an executable element, dispatching to the visit method
* for the specific {@linkplain ElementKind kind} of executable,
* {@code CONSTRUCTOR}, {@code INSTANCE_INIT}, {@code METHOD}, or
* {@code STATIC_INIT}.
*
* @param e {@inheritDoc}
* @param p {@inheritDoc}
* @return the result of the kind-specific visit method
*/
@Override
public R visitExecutable(ExecutableElement e, P p) {
ElementKind k = e.getKind();
switch(k) {
case CONSTRUCTOR:
return visitExecutableAsConstructor(e, p);
case INSTANCE_INIT:
return visitExecutableAsInstanceInit(e, p);
case METHOD:
return visitExecutableAsMethod(e, p);
case STATIC_INIT:
return visitExecutableAsStaticInit(e, p);
default:
throw new AssertionError("Bad kind " + k + " for ExecutableElement" + e);
}
}
/**
* Visits a {@code CONSTRUCTOR} executable element by calling
* {@code defaultAction}.
*
* @param e the element to visit
* @param p a visitor-specified parameter
* @return the result of {@code defaultAction}
*/
public R visitExecutableAsConstructor(ExecutableElement e, P p) {
return defaultAction(e, p);
}
/**
* Visits an {@code INSTANCE_INIT} executable element by calling
* {@code defaultAction}.
*
* @param e the element to visit
* @param p a visitor-specified parameter
* @return the result of {@code defaultAction}
*/
public R visitExecutableAsInstanceInit(ExecutableElement e, P p) {
return defaultAction(e, p);
}
/**
* Visits a {@code METHOD} executable element by calling
* {@code defaultAction}.
*
* @param e the element to visit
* @param p a visitor-specified parameter
* @return the result of {@code defaultAction}
*/
public R visitExecutableAsMethod(ExecutableElement e, P p) {
return defaultAction(e, p);
}
/**
* Visits a {@code STATIC_INIT} executable element by calling
* {@code defaultAction}.
*
* @param e the element to visit
* @param p a visitor-specified parameter
* @return the result of {@code defaultAction}
*/
public R visitExecutableAsStaticInit(ExecutableElement e, P p) {
return defaultAction(e, p);
}
/**
* {@inheritDoc}
*
* The element argument has kind {@code TYPE_PARAMETER}.
*
* @param e {@inheritDoc}
* @param p {@inheritDoc}
* @return {@inheritDoc}
*/
@Override
public R visitTypeParameter(TypeParameterElement e, P p) {
assert e.getKind() == TYPE_PARAMETER: "Bad kind on TypeParameterElement";
return defaultAction(e, p);
}
}