IVariableBinding


1   /*******************************************************************************
2    * Copyright (c) 2000, 2005 IBM Corporation and others.
3    * All rights reserved. This program and the accompanying materials
4    * are made available under the terms of the Eclipse Public License v1.0
5    * which accompanies this distribution, and is available at
6    * http://www.eclipse.org/legal/epl-v10.html
7    *
8    * Contributors:
9    *     IBM Corporation - initial API and implementation
10   *******************************************************************************/
11  
12  package org.eclipse.jdt.core.dom;
13  
14  /**
15   * A variable binding represents either a field of a class or interface, or 
16   * a local variable declaration (including formal parameters, local variables, 
17   * and exception variables).
18   * <p>
19   * This interface is not intended to be implemented by clients.
20   * </p>
21   *
22   * @see ITypeBinding#getDeclaredFields()
23   * @since 2.0
24   */
25  public interface IVariableBinding extends IBinding {
26      
27      /**
28       * Returns whether this binding is for a field.
29       * Note that this method returns <code>true</code> for constants,
30       * including enum constants. This method returns <code>false</code>
31       * for local variables.
32       * 
33       * @return <code>true</code> if this is the binding for a field,
34       *    and <code>false</code> otherwise
35       */ 
36      public boolean isField();
37      
38      /**
39       * Returns whether this binding is for an enum constant.
40       * Note that this method returns <code>false</code> for local variables
41       * and for fields other than enum constants.
42       * 
43       * @return <code>true</code> if this is the binding for an enum constant,
44       *    and <code>false</code> otherwise
45       * @since 3.1
46       */ 
47      public boolean isEnumConstant();
48      
49      /**
50       * Returns the name of the field or local variable declared in this binding.
51       * The name is always a simple identifier.
52       * 
53       * @return the name of this field or local variable
54       */
55      public String   getName();
56      
57      /**
58       * Returns the type binding representing the class or interface
59       * that declares this field.
60       * <p>
61       * The declaring class of a field is the class or interface of which it is
62       * a member. Local variables have no declaring class. The field length of an 
63       * array type has no declaring class.
64       * </p>
65       * 
66       * @return the binding of the class or interface that declares this field,
67       *   or <code>null</code> if none
68       */
69      public ITypeBinding getDeclaringClass();
70  
71      /**
72       * Returns the binding for the type of this field or local variable.
73       * 
74       * @return the binding for the type of this field or local variable
75       */
76      public ITypeBinding getType();
77      
78      /**
79       * Returns a small integer variable id for this variable binding.
80       * <p>
81       * <b>Local variables inside methods:</b> Local variables (and parameters)
82       * declared within a single method are assigned ascending ids in normal
83       * code reading order; var1.getVariableId()&lt;var2.getVariableId() means that var1 is
84       * declared before var2.
85       * </p>
86       * <p>
87       * <b>Local variables outside methods:</b> Local variables declared in a
88       * type's static initializers (or initializer expressions of static fields)
89       * are assigned ascending ids in normal code reading order. Local variables
90       * declared in a type's instance initializers (or initializer expressions
91       * of non-static fields) are assigned ascending ids in normal code reading
92       * order. These ids are useful when checking definite assignment for
93       * static initializers (JLS 16.7) and instance initializers (JLS 16.8), 
94       * respectively.
95       * </p>
96       * <p>
97       * <b>Fields:</b> Fields declared as members of a type are assigned 
98       * ascending ids in normal code reading order; 
99       * field1.getVariableId()&lt;field2.getVariableId() means that field1 is declared before
100      * field2.
101      * </p>
102      * 
103      * @return a small non-negative variable id
104      */
105     public int getVariableId();
106     
107     /**
108      * Returns this binding's constant value if it has one.
109      * Some variables may have a value computed at compile-time. If the type of
110      * the value is a primitive type, the result is the boxed equivalent (i.e.,
111      * int returned as an <code>Integer</code>). If the type of the value is
112      * <code>String</code>, the result is the string itself. If the variable has
113      * no compile-time computed value, the result is <code>null</code>.
114      * (Note: compile-time constant expressions cannot denote <code>null</code>;
115      * JLS2 15.28.). The result is always <code>null</code> for enum constants.
116      * 
117      * @return the constant value, or <code>null</code> if none
118      * @since 3.0
119      */
120     public Object   getConstantValue();
121     
122     /**
123      * Returns the method binding representing the method containing the scope
124      * in which this local variable is declared.
125      * <p>
126      * The declaring method of a method formal parameter is the method itself.
127      * For a local variable declared somewhere within the body of a method,
128      * the declaring method is the enclosing method. When local or anonymous
129      * classes are involved, the declaring method is the innermost such method.
130      * There is no declaring method for a field, or for a local variable
131      * declared in a static or instance initializer; this method returns
132      * <code>null</code> in those cases.
133      * </p>
134      * 
135      * @return the binding of the method or constructor that declares this
136      * local variable, or <code>null</code> if none
137      * @since 3.1
138      */
139     public IMethodBinding getDeclaringMethod();
140     
141     /**
142      * Returns the binding for the variable declaration corresponding to this
143      * variable binding. For a binding for a field declaration in an instance
144      * of a generic type, this method returns the binding for the corresponding
145      * field declaration in the generic type. For other variable bindings,
146      * including all ones for local variables and parameters, this method
147      * returns the same binding.
148      *
149      * @return the variable binding for the originating declaration
150      * @since 3.1
151      */
152     public IVariableBinding getVariableDeclaration();
153 
154 }
155
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