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

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

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 * 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

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 * accompanied this code).

 *

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

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package javax.lang.model.util;

import java.util.List;

import java.util.Map;

import javax.lang.model.AnnotatedConstruct;

import javax.lang.model.element.*;

/**

 * 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 if the package is unique in the environment.

     * If running with modules, all modules in the modules graph are searched for matching packages.

     *

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

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

     */

    PackageElement getPackageElement(CharSequence name);

    /**

     * Returns a package given its fully qualified name, as seen from the given module.

     *

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

     * @param module module relative to which the lookup should happen

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

     * @since 9

     */

    PackageElement getPackageElement(ModuleElement module, CharSequence name);

    /**

     * Returns a type element given its canonical name if the type element is unique in the environment.

     * If running with modules, all modules in the modules graph are searched for matching

     * type elements.

     *

     * @param name  the canonical name

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

     */

    TypeElement getTypeElement(CharSequence name);

    /**

     * Returns a type element given its canonical name, as seen from the given module.

     *

     * @param name  the canonical name

     * @param module module relative to which the lookup should happen

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

     * @since 9

     */

    TypeElement getTypeElement(ModuleElement module, CharSequence name);

    /**

     * Returns a module element given its fully qualified name.

     * If the named module cannot be found, null is returned. One situation where a module

     * cannot be found is if the environment does not include modules, such as

     * an annotation processing environment configured for

     *

     * @param name  the name

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

     * @since 9

     */

    ModuleElement getModuleElement(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 <em>origin</em> of the given element.

     *

     * <p>Note that if this method returns {@link Origin#EXPLICIT

     * EXPLICIT} and the element was created from a class file, then

     * the element may not, in fact, correspond to an explicitly

     * declared construct in source code. This is due to limitations

     * of the fidelity of the class file format in preserving

     * information from source code. For example, at least some

     * versions of the class file format do not preserve whether a

     * constructor was explicitly declared by the programmer or was

     * implicitly declared as the <em>default constructor</em>.

     *

     * @implSpec The default implementation of this method returns

     * {@link Origin#EXPLICIT EXPLICIT}.

     *

     * @param e  the element being examined

     * @return the origin of the given element

     * @since 9

     */

    default Origin getOrigin(Element e) {

        return Origin.EXPLICIT;

    }

    /**

     * Returns the <em>origin</em> of the given annotation mirror.

     *

     * An annotation mirror is {@linkplain Origin#MANDATED mandated}

     * if it is an implicitly declared <em>container annotation</em>

     * used to hold repeated annotations of a repeatable annotation

     * type.

     *

     * <p>Note that if this method returns {@link Origin#EXPLICIT

     * EXPLICIT} and the annotation mirror was created from a class

     * file, then the element may not, in fact, correspond to an

     * explicitly declared construct in source code. This is due to

     * limitations of the fidelity of the class file format in

     * preserving information from source code. For example, at least

     * some versions of the class file format do not preserve whether

     * an annotation was explicitly declared by the programmer or was

     * implicitly declared as a <em>container annotation</em>.

     *

     * @implSpec The default implementation of this method returns

     * {@link Origin#EXPLICIT EXPLICIT}.

     *

     * @param c the construct the annotation mirror modifies

     * @param a the annotation mirror being examined

     * @return the origin of the given annotation mirror

     * @jls 9.6.3 Repeatable Annotation Types

     * @jls 9.7.5 Multiple Annotations of the Same Type

     * @since 9

     */

    default Origin getOrigin(AnnotatedConstruct c,

                             AnnotationMirror a) {

        return Origin.EXPLICIT;

    }

    /**

     * Returns the <em>origin</em> of the given module directive.

     *

     * <p>Note that if this method returns {@link Origin#EXPLICIT

     * EXPLICIT} and the module directive was created from a class

     * file, then the module directive may not, in fact, correspond to

     * an explicitly declared construct in source code. This is due to

     * limitations of the fidelity of the class file format in

     * preserving information from source code. For example, at least

     * some versions of the class file format do not preserve whether

     * a {@code uses} directive was explicitly declared by the

     * programmer or was added as a synthetic construct.

     *

     * <p>Note that an implementation may not be able to reliably

     * determine the origin status of the directive if the directive

     * is created from a class file due to limitations of the fidelity

     * of the class file format in preserving information from source

     * code.

     *

     * @implSpec The default implementation of this method returns

     * {@link Origin#EXPLICIT EXPLICIT}.

     *

     * @param m the module of the directive

     * @param directive  the module directive being examined

     * @return the origin of the given directive

     * @since 9

     */

    default Origin getOrigin(ModuleElement m,

                             ModuleElement.Directive directive) {

        return Origin.EXPLICIT;

    }

    /**

     * The <em>origin</em> of an element or other language model

     * item. The origin of an element or item models how a construct

     * in a program is declared in the source code, explicitly,

     * implicitly, etc.

     *

     * <p>Note that it is possible additional kinds of origin values

     * will be added in future versions of the platform.

     *

     * @jls 13.1 The Form of a Binary

     * @since 9

     */

    public enum Origin {

        /**

         * Describes a construct explicitly declared in source code.

         */

        EXPLICIT,

       /**

         * A mandated construct is one that is not explicitly declared

         * in the source code, but whose presence is mandated by the

         * specification. Such a construct is said to be implicitly

         * declared.

         *

         * One example of a mandated element is a <em>default

         * constructor</em> in a class that contains no explicit

         * constructor declarations.

         *

         * Another example of a mandated construct is an implicitly

         * declared <em>container annotation</em> used to hold

         * multiple annotations of a repeatable annotation type.

         *

         * @jls 8.8.9 Default Constructor

         * @jls 9.6.3 Repeatable Annotation Types

         * @jls 9.7.5 Multiple Annotations of the Same Type

         */

        MANDATED,

       /**

         * A synthetic construct is one that is neither implicitly nor

         * explicitly declared in the source code. Such a construct is

         * typically a translation artifact created by a compiler.

         */

        SYNTHETIC;

        /**

         * Returns {@code true} for values corresponding to constructs

         * that are implicitly or explicitly declared, {@code false}

         * otherwise.

         * @return {@code true} for {@link EXPLICIT} and {@link

         * MANDATED}, {@code false} otherwise.

         */

        public boolean isDeclared() {

            return this != SYNTHETIC;

        }

    }

    /**

     * Returns {@code true} if the executable element is a bridge

     * method, {@code false} otherwise.

     *

     * @implSpec The default implementation of this method returns {@code false}.

     *

     * @param e  the executable being examined

     * @return {@code true} if the executable element is a bridge

     * method, {@code false} otherwise

     * @since 9

     */

    default boolean isBridge(ExecutableElement e) {

        return false;

    }

    /**

     * 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 the module of an element.  The module of a module is

     * itself.

     * If there is no module for the element, null is returned. One situation where there is

     * no module for an element is if the environment does not include modules, such as

     * an annotation processing environment configured for

     *

     * @param type the element being examined

     * @return the module of an element

     * @since 9

     */

    ModuleElement getModuleOf(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);

}