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src/java.compiler/share/classes/javax/lang/model/util/ElementScanner6.java

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  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package javax.lang.model.util;
  27 
  28 import javax.lang.model.element.*;
  29 import javax.annotation.processing.SupportedSourceVersion;
  30 import javax.lang.model.SourceVersion;
  31 import static javax.lang.model.SourceVersion.*;
  32 
  33 
  34 /**
  35  * A scanning visitor of program elements with default behavior
  36  * appropriate for the {@link SourceVersion#RELEASE_6 RELEASE_6}
  37  * source version.  The <code>visit<i>XYZ</i></code> methods in this
  38  * class scan their component elements by calling {@code scan} on
  39  * their {@linkplain Element#getEnclosedElements enclosed elements},
  40  * {@linkplain ExecutableElement#getParameters parameters}, etc., as
  41  * indicated in the individual method specifications.  A subclass can
  42  * control the order elements are visited by overriding the
  43  * <code>visit<i>XYZ</i></code> methods.  Note that clients of a scanner
  44  * may get the desired behavior be invoking {@code v.scan(e, p)} rather
  45  * than {@code v.visit(e, p)} on the root objects of interest.
  46  *
  47  * <p>When a subclass overrides a <code>visit<i>XYZ</i></code> method, the
  48  * new method can cause the enclosed elements to be scanned in the
  49  * default way by calling <code>super.visit<i>XYZ</i></code>.  In this
  50  * fashion, the concrete visitor can control the ordering of traversal
  51  * over the component elements with respect to the additional
  52  * processing; for example, consistently calling
  53  * <code>super.visit<i>XYZ</i></code> at the start of the overridden
  54  * methods will yield a preorder traversal, etc.  If the component
  55  * elements should be traversed in some other order, instead of
  56  * calling <code>super.visit<i>XYZ</i></code>, an overriding visit method
  57  * should call {@code scan} with the elements in the desired order.
  58  *
  59  * <p> Methods in this class may be overridden subject to their
  60  * general contract.  Note that annotating methods in concrete
  61  * subclasses with {@link java.lang.Override @Override} will help
  62  * ensure that methods are overridden as intended.
  63  *
  64  * <p> <b>WARNING:</b> The {@code ElementVisitor} interface
  65  * implemented by this class may have methods added to it in the
  66  * future to accommodate new, currently unknown, language structures
  67  * added to future versions of the Java&trade; programming language.
  68  * Therefore, methods whose names begin with {@code "visit"} may be
  69  * added to this class in the future; to avoid incompatibilities,
  70  * classes which extend this class should not declare any instance
  71  * methods with names beginning with {@code "visit"}.
  72  *
  73  * <p>When such a new visit method is added, the default
  74  * implementation in this class will be to call the {@link
  75  * #visitUnknown visitUnknown} method.  A new element scanner visitor
  76  * class will also be introduced to correspond to the new language




  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package javax.lang.model.util;
  27 
  28 import javax.lang.model.element.*;
  29 import javax.annotation.processing.SupportedSourceVersion;
  30 import javax.lang.model.SourceVersion;
  31 import static javax.lang.model.SourceVersion.*;
  32 
  33 
  34 /**
  35  * A scanning visitor of program elements with default behavior
  36  * appropriate for the {@link SourceVersion#RELEASE_6 RELEASE_6}
  37  * source version.  The <code>visit<i>Xyz</i></code> methods in this
  38  * class scan their component elements by calling {@code scan} on
  39  * their {@linkplain Element#getEnclosedElements enclosed elements},
  40  * {@linkplain ExecutableElement#getParameters parameters}, etc., as
  41  * indicated in the individual method specifications.  A subclass can
  42  * control the order elements are visited by overriding the
  43  * <code>visit<i>Xyz</i></code> methods.  Note that clients of a scanner
  44  * may get the desired behavior be invoking {@code v.scan(e, p)} rather
  45  * than {@code v.visit(e, p)} on the root objects of interest.
  46  *
  47  * <p>When a subclass overrides a <code>visit<i>Xyz</i></code> method, the
  48  * new method can cause the enclosed elements to be scanned in the
  49  * default way by calling <code>super.visit<i>Xyz</i></code>.  In this
  50  * fashion, the concrete visitor can control the ordering of traversal
  51  * over the component elements with respect to the additional
  52  * processing; for example, consistently calling
  53  * <code>super.visit<i>Xyz</i></code> at the start of the overridden
  54  * methods will yield a preorder traversal, etc.  If the component
  55  * elements should be traversed in some other order, instead of
  56  * calling <code>super.visit<i>Xyz</i></code>, an overriding visit method
  57  * should call {@code scan} with the elements in the desired order.
  58  *
  59  * <p> Methods in this class may be overridden subject to their
  60  * general contract.  Note that annotating methods in concrete
  61  * subclasses with {@link java.lang.Override @Override} will help
  62  * ensure that methods are overridden as intended.
  63  *
  64  * <p> <b>WARNING:</b> The {@code ElementVisitor} interface
  65  * implemented by this class may have methods added to it in the
  66  * future to accommodate new, currently unknown, language structures
  67  * added to future versions of the Java&trade; programming language.
  68  * Therefore, methods whose names begin with {@code "visit"} may be
  69  * added to this class in the future; to avoid incompatibilities,
  70  * classes which extend this class should not declare any instance
  71  * methods with names beginning with {@code "visit"}.
  72  *
  73  * <p>When such a new visit method is added, the default
  74  * implementation in this class will be to call the {@link
  75  * #visitUnknown visitUnknown} method.  A new element scanner visitor
  76  * class will also be introduced to correspond to the new language


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