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package javax.lang.model.util;
import javax.lang.model.element.*;
import javax.annotation.processing.SupportedSourceVersion;
import javax.lang.model.SourceVersion;
import static javax.lang.model.SourceVersion.*;
A scanning visitor of program elements with default behavior appropriate for source versions
RELEASE_9 through RELEASE_14. The visitXyz methods in this class scan their component elements by calling scan on their enclosed elements, parameters, etc., as indicated in the individual method specifications. A subclass can control the order elements are visited by overriding the visitXyz methods. Note that clients of a scanner may get the desired behavior be invoking v.scan(e, p) rather than v.visit(e, p) on the root objects of interest. When a subclass overrides a visitXyz method, the
new method can cause the enclosed elements to be scanned in the
default way by calling super.visitXyz. In this
fashion, the concrete visitor can control the ordering of traversal
over the component elements with respect to the additional
processing; for example, consistently calling
super.visitXyz at the start of the overridden
methods will yield a preorder traversal, etc. If the component
elements should be traversed in some other order, instead of
calling super.visitXyz, an overriding visit method should call scan with the elements in the desired order.
Type parameters: See Also: API Note:
Methods in this class may be overridden subject to their general
contract. Since: 9
/**
* A scanning visitor of program elements with default behavior
* appropriate for source versions {@link SourceVersion#RELEASE_9
* RELEASE_9} through {@link SourceVersion#RELEASE_14 RELEASE_14}.
*
* The <code>visit<i>Xyz</i></code> methods in this
* class scan their component elements by calling {@code scan} on
* their {@linkplain Element#getEnclosedElements enclosed elements},
* {@linkplain ExecutableElement#getParameters parameters}, etc., as
* indicated in the individual method specifications. A subclass can
* control the order elements are visited by overriding the
* <code>visit<i>Xyz</i></code> methods. Note that clients of a scanner
* may get the desired behavior be invoking {@code v.scan(e, p)} rather
* than {@code v.visit(e, p)} on the root objects of interest.
*
* <p>When a subclass overrides a <code>visit<i>Xyz</i></code> method, the
* new method can cause the enclosed elements to be scanned in the
* default way by calling <code>super.visit<i>Xyz</i></code>. In this
* fashion, the concrete visitor can control the ordering of traversal
* over the component elements with respect to the additional
* processing; for example, consistently calling
* <code>super.visit<i>Xyz</i></code> at the start of the overridden
* methods will yield a preorder traversal, etc. If the component
* elements should be traversed in some other order, instead of
* calling <code>super.visit<i>Xyz</i></code>, an overriding visit method
* should call {@code scan} with the elements in the desired order.
*
* @apiNote
* Methods in this class may be overridden subject to their general
* contract.
*
* @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.
*
* @see <a href="ElementScanner6.html#note_for_subclasses"><strong>Compatibility note for subclasses</strong></a>
* @see ElementScanner6
* @see ElementScanner7
* @see ElementScanner8
* @see ElementScanner14
* @since 9
*/
@SupportedSourceVersion(RELEASE_14)
public class ElementScanner9<R, P> extends ElementScanner8<R, P> {
Constructor for concrete subclasses; uses null for the default value. /**
* Constructor for concrete subclasses; uses {@code null} for the
* default value.
*/
protected ElementScanner9(){
super(null);
}
Constructor for concrete subclasses; uses the argument for the
default value.
Params: - defaultValue – the default value
/**
* Constructor for concrete subclasses; uses the argument for the
* default value.
*
* @param defaultValue the default value
*/
protected ElementScanner9(R defaultValue){
super(defaultValue);
}
{@inheritDoc}
Params: - e – the element to visit
- p – a visitor-specified parameter
Implementation Requirements: This implementation scans the enclosed elements. Returns: the result of the scan
/**
* {@inheritDoc}
*
* @implSpec This implementation scans the enclosed elements.
*
* @param e the element to visit
* @param p a visitor-specified parameter
* @return the result of the scan
*/
@Override
public R visitModule(ModuleElement e, P p) {
return scan(e.getEnclosedElements(), p); // TODO: Hmmm, this might not be right
}
}