71 * classes which extend this class should not declare any instance
72 * methods with names beginning with {@code "visit"}.
73 *
74 * <p>When such a new visit method is added, the default
75 * implementation in this class will be to call the {@link
76 * #visitUnknown visitUnknown} method. A new element scanner visitor
77 * class will also be introduced to correspond to the new language
78 * level; this visitor will have different default behavior for the
79 * visit method in question. When the new visitor is introduced, all
80 * or portions of this visitor may be deprecated.
81 *
82 * @param <R> the return type of this visitor's methods. Use {@link
83 * Void} for visitors that do not need to return results.
84 * @param <P> the type of the additional parameter to this visitor's
85 * methods. Use {@code Void} for visitors that do not need an
86 * additional parameter.
87 *
88 * @author Joseph D. Darcy
89 * @author Scott Seligman
90 * @author Peter von der Ahé
91 * @since 1.6
92 */
93 @SupportedSourceVersion(RELEASE_6)
94 public class ElementScanner6<R, P> extends AbstractElementVisitor6<R, P> {
95 /**
96 * The specified default value.
97 */
98 protected final R DEFAULT_VALUE;
99
100 /**
101 * Constructor for concrete subclasses; uses {@code null} for the
102 * default value.
103 */
104 protected ElementScanner6(){
105 DEFAULT_VALUE = null;
106 }
107
108 /**
109 * Constructor for concrete subclasses; uses the argument for the
110 * default value.
111 */
112 protected ElementScanner6(R defaultValue){
113 DEFAULT_VALUE = defaultValue;
114 }
115
116 /**
117 * Iterates over the given elements and calls {@link
118 * #scan(Element, Object) scan(Element, P)} on each one. Returns
119 * the result of the last call to {@code scan} or {@code
120 * DEFAULT_VALUE} for an empty iterable.
121 *
122 * @param iterable the elements to scan
123 * @param p additional parameter
124 * @return the scan of the last element or {@code DEFAULT_VALUE} if no elements
125 */
126 public final R scan(Iterable<? extends Element> iterable, P p) {
127 R result = DEFAULT_VALUE;
128 for(Element e : iterable)
129 result = scan(e, p);
130 return result;
131 }
132
133 /**
134 * Processes an element by calling {@code e.accept(this, p)};
135 * this method may be overridden by subclasses.
136 * @return the result of visiting {@code e}.
137 */
138 public R scan(Element e, P p) {
139 return e.accept(this, p);
140 }
141
142 /**
143 * Convenience method equivalent to {@code v.scan(e, null)}.
144 * @return the result of scanning {@code e}.
145 */
146 public final R scan(Element e) {
147 return scan(e, null);
148 }
149
150 /**
151 * {@inheritDoc} This implementation scans the enclosed elements.
152 *
153 * @param e the element to visit
154 * @param p a visitor-specified parameter
155 * @return the result of scanning
156 */
157 public R visitPackage(PackageElement e, P p) {
158 return scan(e.getEnclosedElements(), p);
159 }
160
161 /**
162 * {@inheritDoc} This implementation scans the enclosed elements.
163 *
164 * @param e the element to visit
165 * @param p a visitor-specified parameter
166 * @return the result of scanning
167 */
168 public R visitType(TypeElement e, P p) {
169 return scan(e.getEnclosedElements(), p);
170 }
171
172 /**
173 * {@inheritDoc} This implementation scans the enclosed elements.
174 *
175 * @param e the element to visit
176 * @param p a visitor-specified parameter
177 * @return the result of scanning
178 */
179 public R visitVariable(VariableElement e, P p) {
180 return scan(e.getEnclosedElements(), p);
181 }
182
183 /**
184 * {@inheritDoc} This implementation scans the parameters.
185 *
186 * @param e the element to visit
187 * @param p a visitor-specified parameter
188 * @return the result of scanning
189 */
190 public R visitExecutable(ExecutableElement e, P p) {
191 return scan(e.getParameters(), p);
192 }
193
194 /**
195 * {@inheritDoc} This implementation scans the enclosed elements.
196 *
197 * @param e the element to visit
198 * @param p a visitor-specified parameter
199 * @return the result of scanning
200 */
201 public R visitTypeParameter(TypeParameterElement e, P p) {
202 return scan(e.getEnclosedElements(), p);
203 }
204 }
|
71 * classes which extend this class should not declare any instance
72 * methods with names beginning with {@code "visit"}.
73 *
74 * <p>When such a new visit method is added, the default
75 * implementation in this class will be to call the {@link
76 * #visitUnknown visitUnknown} method. A new element scanner visitor
77 * class will also be introduced to correspond to the new language
78 * level; this visitor will have different default behavior for the
79 * visit method in question. When the new visitor is introduced, all
80 * or portions of this visitor may be deprecated.
81 *
82 * @param <R> the return type of this visitor's methods. Use {@link
83 * Void} for visitors that do not need to return results.
84 * @param <P> the type of the additional parameter to this visitor's
85 * methods. Use {@code Void} for visitors that do not need an
86 * additional parameter.
87 *
88 * @author Joseph D. Darcy
89 * @author Scott Seligman
90 * @author Peter von der Ahé
91 *
92 * @see ElementScanner7
93 * @since 1.6
94 */
95 @SupportedSourceVersion(RELEASE_6)
96 public class ElementScanner6<R, P> extends SharedElementScanner<R, P> {
97 /**
98 * Constructor for concrete subclasses; uses {@code null} for the
99 * default value.
100 */
101 protected ElementScanner6(){
102 super();
103 }
104
105 /**
106 * Constructor for concrete subclasses; uses the argument for the
107 * default value.
108 */
109 protected ElementScanner6(R defaultValue){
110 super(defaultValue);
111 }
112 }
|