/*******************************************************************************
* Copyright (c) 2000, 2014 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.jdt.core.dom;
import org.eclipse.jdt.core.IAnnotation;
import org.eclipse.jdt.core.IJavaElement;
/**
* A binding represents a named entity in the Java language. The world of
* bindings provides an integrated picture of the structure of the program as
* seen from the compiler's point of view. This interface declares protocols
* common to the various different kinds of named entities in the Java language:
* packages, types, fields, methods, constructors, local variables, and annotations.
*
* @see IPackageBinding
* @see ITypeBinding
* @see IVariableBinding
* @see IMethodBinding
* @see IAnnotationBinding
* @see IMemberValuePairBinding
* @since 2.0
* @noimplement This interface is not intended to be implemented by clients.
*/
public interface IBinding {
/**
* Kind constant (value 1) indicating a package binding.
* Bindings of this kind can be safely cast to <code>IPackageBinding</code>.
*
* @see #getKind()
* @see IPackageBinding
*/
public static final int PACKAGE = 1;
/**
* Kind constant (value 2) indicating a type binding.
* Bindings of this kind can be safely cast to <code>ITypeBinding</code>.
*
* @see #getKind()
* @see ITypeBinding
*/
public static final int TYPE = 2;
/**
* Kind constant (value 3) indicating a field or local variable binding.
* Bindings of this kind can be safely cast to <code>IVariableBinding</code>.
*
* @see #getKind()
* @see IVariableBinding
*/
public static final int VARIABLE = 3;
/**
* Kind constant (value 4) indicating a method or constructor binding.
* Bindings of this kind can be safely cast to <code>IMethodBinding</code>.
*
* @see #getKind()
* @see IMethodBinding
*/
public static final int METHOD = 4;
/**
* Kind constant (value 5) indicating an annotation binding.
* Bindings of this kind can be safely cast to <code>IAnnotationBinding</code>.
*
* @see #getKind()
* @see IAnnotationBinding
* @since 3.2
*/
public static final int ANNOTATION = 5;
/**
* Kind constant (value 6) indicating a member value pair binding.
* Bindings of this kind can be safely cast to <code>IMemberValuePairBinding</code>.
*
* @see #getKind()
* @see IMemberValuePairBinding
* @since 3.2
*/
public static final int MEMBER_VALUE_PAIR = 6;
/**
* Returns the resolved declaration annotations associated with this binding.
* <ul>
* <li>Package bindings - these are annotations on a package declaration.
* </li>
* <li>Type bindings - these are annotations on a class, interface, enum,
* or annotation type declaration. The result is the same regardless of
* whether the type is parameterized.</li>
* <li>Method bindings - these are annotations on a method or constructor
* declaration. The result is the same regardless of whether the method is
* parameterized.</li>
* <li>Variable bindings - these are annotations on a field, enum constant,
* or formal parameter declaration.</li>
* <li>Annotation bindings - an empty array is always returned</li>
* <li>Member value pair bindings - an empty array is always returned</li>
* </ul>
* <p>
* <b>Note:</b> This method only returns declaration annotations.
* <em>Type annotations</em> in the sense of JLS8 9.7.4 are <em>not</em> returned.
* Type annotations can be retrieved via {@link ITypeBinding#getTypeAnnotations()}.
* </p>
*
* @return the list of resolved declaration annotations, or the empty list if there are no
* declaration annotations associated with the entity represented by this binding
* @since 3.2
*/
public IAnnotationBinding[] getAnnotations();
/**
* Returns the kind of bindings this is. That is one of the kind constants:
* <code>PACKAGE</code>,
* <code>TYPE</code>,
* <code>VARIABLE</code>,
* <code>METHOD</code>,
* <code>ANNOTATION</code>,
* or <code>MEMBER_VALUE_PAIR</code>.
* <p>
* Note that additional kinds might be added in the
* future, so clients should not assume this list is exhaustive and
* should program defensively, e.g. by having a reasonable default
* in a switch statement.
* </p>
* @return one of the kind constants
*/
public int getKind();
/**
* Returns the name of this binding.
* Details of the name are specified with each specific kind of binding.
*
* @return the name of this binding
*/
public String getName();
/**
* Returns the modifiers for this binding.
* <p>
* Note that 'deprecated' is not included among the modifiers.
* Use <code>isDeprecated</code> to find out whether a binding is deprecated.
* </p>
*
* @return the bit-wise or of <code>Modifier</code> constants
* @see Modifier
*/
public int getModifiers();
/**
* Return whether this binding is for something that is deprecated.
* A deprecated class, interface, field, method, or constructor is one that
* is marked with the 'deprecated' tag in its Javadoc comment.
*
* @return <code>true</code> if this binding is deprecated, and
* <code>false</code> otherwise
*/
public boolean isDeprecated();
/**
* Return whether this binding is created because the bindings recovery is enabled. This binding is considered
* to be incomplete. Its internal state might be incomplete.
*
* @return <code>true</code> if this binding is a recovered binding, and
* <code>false</code> otherwise
* @since 3.3
*/
public boolean isRecovered();
/**
* Returns whether this binding is synthetic. A synthetic binding is one that
* was made up by the compiler, rather than something declared in the
* source code. Note that default constructors (the 0-argument constructor that
* the compiler generates for class declarations with no explicit constructors
* declarations) are not generally considered synthetic (although they
* may be if the class itself is synthetic).
* But see {@link IMethodBinding#isDefaultConstructor() IMethodBinding.isDefaultConstructor}
* for cases where the compiled-generated default constructor can be recognized
* instead.
*
* @return <code>true</code> if this binding is synthetic, and
* <code>false</code> otherwise
* @see IMethodBinding#isDefaultConstructor()
*/
public boolean isSynthetic();
/**
* Returns the Java element that corresponds to this binding.
* Returns <code>null</code> if this binding has no corresponding
* Java element.
* <p>
* For array types, this method returns the Java element that corresponds
* to the array's element type. For raw and parameterized types, this method
* returns the Java element of the erasure. For annotations, this method
* returns the Java element of the annotation (i.e. an {@link IAnnotation}).
* </p>
* <p>
* Here are the cases where a <code>null</code> should be expected:
* <ul>
* <li>primitive types, including void</li>
* <li>null type</li>
* <li>wildcard types</li>
* <li>capture types</li>
* <li>array types of any of the above</li>
* <li>the "length" field of an array type</li>
* <li>the default constructor of a source class</li>
* <li>the constructor of an anonymous class</li>
* <li>member value pairs</li>
* <li>synthetic bindings</li>
* </ul>
* For all other kind of type, method, variable, annotation and package bindings,
* this method returns non-<code>null</code>.
* </p>
*
* @return the Java element that corresponds to this binding,
* or <code>null</code> if none
* @since 3.1
*/
public IJavaElement getJavaElement();
/**
* Returns the key for this binding.
* <p>
* Within a single cluster of bindings (produced by the same call to an
* {@code ASTParser#create*(*)} method)), each binding has a distinct key.
* The keys are generated in a manner that is predictable and as
* stable as possible. This last property makes these keys useful for
* comparing bindings between different clusters of bindings (for example,
* the bindings between the "before" and "after" ASTs of the same
* compilation unit).
* </p>
* <p>
* The exact details of how the keys are generated is unspecified.
* However, it is a function of the following information:
* <ul>
* <li>packages - the name of the package (for an unnamed package,
* some internal id)</li>
* <li>classes or interfaces - the VM name of the type and the key
* of its package</li>
* <li>array types - the key of the component type and number of
* dimensions</li>
* <li>primitive types - the name of the primitive type</li>
* <li>fields - the name of the field and the key of its declaring
* type</li>
* <li>methods - the name of the method, the key of its declaring
* type, and the keys of the parameter types</li>
* <li>constructors - the key of its declaring class, and the
* keys of the parameter types</li>
* <li>local variables - the name of the local variable, the index of the
* declaring block relative to its parent, the key of its method</li>
* <li>local types - the name of the type, the index of the declaring
* block relative to its parent, the key of its method</li>
* <li>anonymous types - the occurrence count of the anonymous
* type relative to its declaring type, the key of its declaring type</li>
* <li>enum types - treated like classes</li>
* <li>annotation types - treated like interfaces</li>
* <li>type variables - the name of the type variable and
* the key of the generic type or generic method that declares that
* type variable</li>
* <li>wildcard types - the key of the optional wildcard type bound</li>
* <li>capture type bindings - the key of the wildcard captured</li>
* <li>generic type instances - the key of the generic type and the keys
* of the type arguments used to instantiate it, and whether the
* instance is explicit (a parameterized type reference) or
* implicit (a raw type reference)</li>
* <li>generic method instances - the key of the generic method and the keys
* of the type arguments used to instantiate it, and whether the
* instance is explicit (a parameterized method reference) or
* implicit (a raw method reference)</li>
* <li>members of generic type instances - the key of the generic type
* instance and the key of the corresponding member in the generic
* type</li>
* <li>annotations - the key of the annotated element and the key of
* the annotation type</li>
* </ul>
* </p>
* <p>
* The key for a type binding does <em>not</em> contain {@link ITypeBinding#getTypeAnnotations() type annotations},
* so type bindings with different type annotations may have the same key (iff they denote the same un-annotated type).
* By construction, this also applies to method bindings if their declaring types contain type annotations.
* </p>
* <p>Note that the key for member value pair bindings is
* not yet implemented. This method returns <code>null</code> for that kind of bindings.<br>
* Recovered bindings have a unique key.
* </p>
*
* @return the key for this binding
*/
public String getKey();
/**
* There is no special definition of equality for bindings; equality is
* simply object identity. Within the context of a single cluster of
* bindings (produced by the same call to an {@code ASTParser#create*(*)} method),
* each binding is represented by a separate object. However,
* between different clusters of bindings, the binding objects may or may
* not be different; in these cases, the client should compare bindings
* using {@link #isEqualTo(IBinding)}, which is functionally equivalent to
* checking their keys for equality.
* <p>
* Since JLS8, type bindings can contain {@link ITypeBinding#getTypeAnnotations() type annotations}.
* Note that type bindings that denote the same un-annotated type have the same {@link #getKey() key},
* but they are not identical if they contain different type annotations.
* Type bindings that contain the same type annotations may or may not be identical.
* </p>
*
* @param obj {@inheritDoc}
* @return {@inheritDoc}
* @see ITypeBinding#getTypeDeclaration()
*/
public boolean equals(Object obj);
/**
* Returns whether this binding has the same key as that of the given
* binding. Within the context of a single cluster of bindings
* (produced by the same call to an {@code ASTParser#create*(*)} method), each
* binding is represented by a distinct object. However, between
* different clusters of bindings, the binding objects may or may
* not be different objects; in these cases, the binding keys
* are used where available.
*
* <p>
* Note that type bindings that only differ in their {@link ITypeBinding#getTypeAnnotations() type annotations}
* have the same {@link IBinding#getKey() key}, and hence this method returns
* <code>true</code> for such type bindings. By construction of the key, this also applies
* to method bindings if their declaring types contain type annotations.
* </p>
*
* @param binding the other binding, or <code>null</code>
* @return <code>true</code> if the given binding is the identical
* object as this binding, or if the keys of both bindings are the
* same string; <code>false</code> if the given binding is
* <code>null</code>, or if the bindings do not have the same key,
* or if one or both of the bindings have no key
* @see #getKey()
* @since 3.1
*/
public boolean isEqualTo(IBinding binding);
/**
* Returns a string representation of this binding suitable for debugging
* purposes only.
*
* @return a debug string
*/
public String toString();
}