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 * Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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package javax.lang.model.util;

import java.util.List;

import java.util.Map;

import javax.lang.model.element.*;

import javax.lang.model.type.*;

/**

 * Utility methods for operating on program elements.

 *

 * <p><b>Compatibility Note:</b> Methods may be added to this interface

 * in future releases of the platform.

 *

 * @author Joseph D. Darcy

 * @author Scott Seligman

 * @author Peter von der Ahé

 * @see javax.annotation.processing.ProcessingEnvironment#getElementUtils

 * @since 1.6

 */

public interface Elements {

    /**

     * Returns a package given its fully qualified name.

     *

     * @param name  fully qualified package name, or "" for an unnamed package

     * @return the named package, or {@code null} if it cannot be found

     */

    PackageElement getPackageElement(CharSequence name);

    /**

     * Returns a type element given its canonical name.

     *

     * @param name  the canonical name

     * @return the named type element, or {@code null} if it cannot be found

     */

    TypeElement getTypeElement(CharSequence name);

    /**

     * Returns the values of an annotation's elements, including defaults.

     *

     * @see AnnotationMirror#getElementValues()

     * @param a  annotation to examine

     * @return the values of the annotation's elements, including defaults

     */

    Map<? extends ExecutableElement, ? extends AnnotationValue>

            getElementValuesWithDefaults(AnnotationMirror a);

    /**

     * Returns the text of the documentation ("Javadoc")

     * comment of an element.

     *

     * <p> A documentation comment of an element is a comment that

     * begins with "{@code /**}" , ends with a separate

     * "<code>*&#47;</code>", and immediately precedes the element,

     * ignoring white space.  Therefore, a documentation comment

     * contains at least three"{@code *}" characters.  The text

     * returned for the documentation comment is a processed form of

     * the comment as it appears in source code.  The leading "{@code

     * /**}" and trailing "<code>*&#47;</code>" are removed.  For lines

     * of the comment starting after the initial "{@code /**}",

     * leading white space characters are discarded as are any

     * consecutive "{@code *}" characters appearing after the white

     * space or starting the line.  The processed lines are then

     * concatenated together (including line terminators) and

     * returned.

     *

     * @param e  the element being examined

     * @return the documentation comment of the element, or {@code null}

     *          if there is none

     * @jls 3.6 White Space

     */

    String getDocComment(Element e);

    /**

     * Returns {@code true} if the element is deprecated, {@code false} otherwise.

     *

     * @param e  the element being examined

     * @return {@code true} if the element is deprecated, {@code false} otherwise

     */

    boolean isDeprecated(Element e);

    /**

     * Returns the <i>binary name</i> of a type element.

     *

     * @param type  the type element being examined

     * @return the binary name

     *

     * @see TypeElement#getQualifiedName

     * @jls 13.1 The Form of a Binary

     */

    Name getBinaryName(TypeElement type);

    /**

     * Returns the package of an element.  The package of a package is

     * itself.

     *

     * @param type the element being examined

     * @return the package of an element

     */

    PackageElement getPackageOf(Element type);

    /**

     * Returns all members of a type element, whether inherited or

     * declared directly.  For a class the result also includes its

     * constructors, but not local or anonymous classes.

     *

     * <p>Note that elements of certain kinds can be isolated using

     * methods in {@link ElementFilter}.

     *

     * @param type  the type being examined

     * @return all members of the type

     * @see Element#getEnclosedElements

     */

    List<? extends Element> getAllMembers(TypeElement type);

    /**

     * Returns all annotations <i>present</i> on an element, whether

     * directly present or present via inheritance.

     *

     * @param e  the element being examined

     * @return all annotations of the element

     * @see Element#getAnnotationMirrors

     * @see javax.lang.model.AnnotatedConstruct

     */

    List<? extends AnnotationMirror> getAllAnnotationMirrors(Element e);

    /**

     * Tests whether one type, method, or field hides another.

     *

     * @param hider   the first element

     * @param hidden  the second element

     * @return {@code true} if and only if the first element hides

     *          the second

     */

    boolean hides(Element hider, Element hidden);

    /**

     * Tests whether one method, as a member of a given type,

     * overrides another method.

     * When a non-abstract method overrides an abstract one, the

     * former is also said to <i>implement</i> the latter.

     *

     * <p> In the simplest and most typical usage, the value of the

     * {@code type} parameter will simply be the class or interface

     * directly enclosing {@code overrider} (the possibly-overriding

     * method).  For example, suppose {@code m1} represents the method

     * {@code String.hashCode} and {@code m2} represents {@code

     * Object.hashCode}.  We can then ask whether {@code m1} overrides

     * {@code m2} within the class {@code String} (it does):

     *

     * <blockquote>

     * {@code assert elements.overrides(m1, m2,

     *          elements.getTypeElement("java.lang.String")); }

     * </blockquote>

     *

     * A more interesting case can be illustrated by the following example

     * in which a method in type {@code A} does not override a

     * like-named method in type {@code B}:

     *

     * <blockquote>

     * {@code class A { public void m() {} } }<br>

     * {@code interface B { void m(); } }<br>

     * ...<br>

     * {@code m1 = ...;  // A.m }<br>

     * {@code m2 = ...;  // B.m }<br>

     * {@code assert ! elements.overrides(m1, m2,

     *          elements.getTypeElement("A")); }

     * </blockquote>

     *

     * When viewed as a member of a third type {@code C}, however,

     * the method in {@code A} does override the one in {@code B}:

     *

     * <blockquote>

     * {@code class C extends A implements B {} }<br>

     * ...<br>

     * {@code assert elements.overrides(m1, m2,

     *          elements.getTypeElement("C")); }

     * </blockquote>

     *

     * @param overrider  the first method, possible overrider

     * @param overridden  the second method, possibly being overridden

     * @param type   the type of which the first method is a member

     * @return {@code true} if and only if the first method overrides

     *          the second

     * @jls 8.4.8 Inheritance, Overriding, and Hiding

     * @jls 9.4.1 Inheritance and Overriding

     */

    boolean overrides(ExecutableElement overrider, ExecutableElement overridden,

                      TypeElement type);

    /**

     * Returns the text of a <i>constant expression</i> representing a

     * primitive value or a string.

     * The text returned is in a form suitable for representing the value

     * in source code.

     *

     * @param value  a primitive value or string

     * @return the text of a constant expression

     * @throws IllegalArgumentException if the argument is not a primitive

     *          value or string

     *

     * @see VariableElement#getConstantValue()

     */

    String getConstantExpression(Object value);

    /**

     * Prints a representation of the elements to the given writer in

     * the specified order.  The main purpose of this method is for

     * diagnostics.  The exact format of the output is <em>not</em>

     * specified and is subject to change.

     *

     * @param w the writer to print the output to

     * @param elements the elements to print

     */

    void printElements(java.io.Writer w, Element... elements);

    /**

     * Return a name with the same sequence of characters as the

     * argument.

     *

     * @param cs the character sequence to return as a name

     * @return a name with the same sequence of characters as the argument

     */

    Name getName(CharSequence cs);

    /**

     * Returns {@code true} if the type element is a functional interface, {@code false} otherwise.

     *

     * @param type the type element being examined

     * @return {@code true} if the element is a functional interface, {@code false} otherwise

     * @jls 9.8 Functional Interfaces

     * @since 1.8

     */

    boolean isFunctionalInterface(TypeElement type);

}