| 1 | /******************************************************************************* |
|---|---|
| 2 | * Copyright (c) 2013, 2014 IBM Corporation and others. |
| 3 | * |
| 4 | * This program and the accompanying materials |
| 5 | * are made available under the terms of the Eclipse Public License 2.0 |
| 6 | * which accompanies this distribution, and is available at |
| 7 | * https://www.eclipse.org/legal/epl-2.0/ |
| 8 | * |
| 9 | * SPDX-License-Identifier: EPL-2.0 |
| 10 | * |
| 11 | * Contributors: |
| 12 | * IBM Corporation - initial API and implementation |
| 13 | *******************************************************************************/ |
| 14 | package org.eclipse.jdt.core.dom; |
| 15 | |
| 16 | import java.util.ArrayList; |
| 17 | import java.util.List; |
| 18 | |
| 19 | /** |
| 20 | * Lambda expression AST node type (added in JLS8 API). |
| 21 | * <pre> |
| 22 | * LambdaExpression: |
| 23 | * Identifier <b>-></b> Body |
| 24 | * <b>(</b> [ Identifier { <b>,</b> Identifier } ] <b>)</b> <b>-></b> Body |
| 25 | * <b>(</b> [ FormalParameter { <b>,</b> FormalParameter } ] <b>)</b> <b>-></b> Body |
| 26 | * </pre> |
| 27 | * |
| 28 | *<p> |
| 29 | * The first two forms use {@link VariableDeclarationFragment} for the parameter or parameters, |
| 30 | * while the third form uses {@link SingleVariableDeclaration}.</p> |
| 31 | *<p>The Body can be either a {@link Block} or an {@link Expression}.</p> |
| 32 | * |
| 33 | * @since 3.10 |
| 34 | * @noinstantiate This class is not intended to be instantiated by clients |
| 35 | */ |
| 36 | @SuppressWarnings({"rawtypes", "unchecked"}) |
| 37 | public class LambdaExpression extends Expression { |
| 38 | |
| 39 | /** |
| 40 | * The "parentheses" structural property of this node type (type: {@link Boolean}). |
| 41 | * <p> |
| 42 | * Note that parentheses are required unless {@link #parameters()} contains |
| 43 | * just a single {@link VariableDeclarationFragment}. |
| 44 | * ASTRewrite may ignore this property if necessary. |
| 45 | * </p> |
| 46 | */ |
| 47 | public static final SimplePropertyDescriptor PARENTHESES_PROPERTY = |
| 48 | new SimplePropertyDescriptor(LambdaExpression.class, "parentheses", boolean.class, MANDATORY); //$NON-NLS-1$ |
| 49 | |
| 50 | /** |
| 51 | * The "parameters" structural property of this node type (element type: {@link VariableDeclaration}). |
| 52 | * <p> |
| 53 | * Note that all elements must be of the same type, either all {@link SingleVariableDeclaration} or all {@link VariableDeclarationFragment}. |
| 54 | * </p> |
| 55 | */ |
| 56 | public static final ChildListPropertyDescriptor PARAMETERS_PROPERTY = |
| 57 | new ChildListPropertyDescriptor(LambdaExpression.class, "parameters", VariableDeclaration.class, CYCLE_RISK); //$NON-NLS-1$ |
| 58 | |
| 59 | /** |
| 60 | * The "body" structural property of this node type (child type: {@link ASTNode}, |
| 61 | * must be either a {@link Block} or an {@link Expression}). |
| 62 | */ |
| 63 | public static final ChildPropertyDescriptor BODY_PROPERTY = |
| 64 | new ChildPropertyDescriptor(LambdaExpression.class, "body", ASTNode.class, MANDATORY, CYCLE_RISK); //$NON-NLS-1$ |
| 65 | |
| 66 | /** |
| 67 | * A list of property descriptors (element type: |
| 68 | * {@link StructuralPropertyDescriptor}), |
| 69 | * or null if uninitialized. |
| 70 | */ |
| 71 | private static final List PROPERTY_DESCRIPTORS_8_0; |
| 72 | |
| 73 | static { |
| 74 | List propertyList = new ArrayList(4); |
| 75 | createPropertyList(LambdaExpression.class, propertyList); |
| 76 | addProperty(PARENTHESES_PROPERTY, propertyList); |
| 77 | addProperty(PARAMETERS_PROPERTY, propertyList); |
| 78 | addProperty(BODY_PROPERTY, propertyList); |
| 79 | PROPERTY_DESCRIPTORS_8_0 = reapPropertyList(propertyList); |
| 80 | } |
| 81 | |
| 82 | /** |
| 83 | * Returns a list of structural property descriptors for this node type. |
| 84 | * Clients must not modify the result. |
| 85 | * |
| 86 | * @param apiLevel the API level; one of the AST.JLS* constants |
| 87 | * @return a list of property descriptors (element type: |
| 88 | * {@link StructuralPropertyDescriptor}) |
| 89 | */ |
| 90 | public static List propertyDescriptors(int apiLevel) { |
| 91 | return PROPERTY_DESCRIPTORS_8_0; |
| 92 | } |
| 93 | |
| 94 | /** |
| 95 | * Indicates whether parentheses are present or not. |
| 96 | * Defaults to <code>true</code>. |
| 97 | */ |
| 98 | private boolean hasParentheses = true; |
| 99 | |
| 100 | /** |
| 101 | * The parameter declarations |
| 102 | * (element type: {@link VariableDeclaration}). |
| 103 | * Defaults to an empty list. |
| 104 | */ |
| 105 | private ASTNode.NodeList parameters = |
| 106 | new ASTNode.NodeList(PARAMETERS_PROPERTY); |
| 107 | |
| 108 | /** |
| 109 | * The method body. |
| 110 | * The method body; lazily initialized, defaults to an empty Block. |
| 111 | */ |
| 112 | private ASTNode body = null; |
| 113 | |
| 114 | /** |
| 115 | * Creates a new AST node for a LambdaExpression declaration owned |
| 116 | * by the given AST. |
| 117 | * <p> |
| 118 | * N.B. This constructor is package-private; all subclasses must be |
| 119 | * declared in the same package; clients are unable to declare |
| 120 | * additional subclasses. |
| 121 | * </p> |
| 122 | * |
| 123 | * @param ast the AST that is to own this node |
| 124 | */ |
| 125 | LambdaExpression(AST ast) { |
| 126 | super(ast); |
| 127 | unsupportedIn2_3_4(); |
| 128 | } |
| 129 | |
| 130 | @Override |
| 131 | final List internalStructuralPropertiesForType(int apiLevel) { |
| 132 | return propertyDescriptors(apiLevel); |
| 133 | } |
| 134 | |
| 135 | @Override |
| 136 | final boolean internalGetSetBooleanProperty(SimplePropertyDescriptor property, boolean get, boolean value) { |
| 137 | if (property == PARENTHESES_PROPERTY) { |
| 138 | if (get) { |
| 139 | return hasParentheses(); |
| 140 | } else { |
| 141 | setParentheses(value); |
| 142 | return false; |
| 143 | } |
| 144 | } |
| 145 | // allow default implementation to flag the error |
| 146 | return super.internalGetSetBooleanProperty(property, get, value); |
| 147 | } |
| 148 | |
| 149 | @Override |
| 150 | final List internalGetChildListProperty(ChildListPropertyDescriptor property) { |
| 151 | if (property == PARAMETERS_PROPERTY) { |
| 152 | return parameters(); |
| 153 | } |
| 154 | // allow default implementation to flag the error |
| 155 | return super.internalGetChildListProperty(property); |
| 156 | } |
| 157 | |
| 158 | @Override |
| 159 | final ASTNode internalGetSetChildProperty(ChildPropertyDescriptor property, boolean get, ASTNode child) { |
| 160 | if (property == BODY_PROPERTY) { |
| 161 | if (get) { |
| 162 | return getBody(); |
| 163 | } else { |
| 164 | setBody( child); |
| 165 | return null; |
| 166 | } |
| 167 | } |
| 168 | // allow default implementation to flag the error |
| 169 | return super.internalGetSetChildProperty(property, get, child); |
| 170 | } |
| 171 | |
| 172 | @Override |
| 173 | final int getNodeType0() { |
| 174 | return LAMBDA_EXPRESSION; |
| 175 | } |
| 176 | |
| 177 | @Override |
| 178 | ASTNode clone0(AST target) { |
| 179 | LambdaExpression result = new LambdaExpression(target); |
| 180 | result.setSourceRange(getStartPosition(), getLength()); |
| 181 | result.setParentheses(hasParentheses()); |
| 182 | result.parameters().addAll(ASTNode.copySubtrees(target, parameters())); |
| 183 | result.setBody(ASTNode.copySubtree(target, getBody())); |
| 184 | return result; |
| 185 | } |
| 186 | |
| 187 | @Override |
| 188 | final boolean subtreeMatch0(ASTMatcher matcher, Object other) { |
| 189 | // dispatch to correct overloaded match method |
| 190 | return matcher.match(this, other); |
| 191 | } |
| 192 | |
| 193 | @Override |
| 194 | void accept0(ASTVisitor visitor) { |
| 195 | boolean visitChildren = visitor.visit(this); |
| 196 | if (visitChildren) { |
| 197 | // visit children in normal left to right reading order |
| 198 | acceptChildren(visitor, this.parameters); |
| 199 | acceptChild(visitor, getBody()); |
| 200 | } |
| 201 | visitor.endVisit(this); |
| 202 | } |
| 203 | |
| 204 | /** |
| 205 | * Returns whether parentheses around the parameters are present or not. |
| 206 | * <p> |
| 207 | * Note that parentheses are required unless {@link #parameters()} contains |
| 208 | * just a single {@link VariableDeclarationFragment}. |
| 209 | * ASTRewrite may ignore this property if necessary. |
| 210 | * </p> |
| 211 | * |
| 212 | * @return <code>true</code> if this lambda expression has parentheses around |
| 213 | * its parameters and <code>false</code> otherwise |
| 214 | */ |
| 215 | public boolean hasParentheses() { |
| 216 | return this.hasParentheses; |
| 217 | } |
| 218 | |
| 219 | /** |
| 220 | * Sets whether this lambda expression has parentheses around its parameters or not. |
| 221 | * <p> |
| 222 | * Note that parentheses are required unless {@link #parameters()} contains |
| 223 | * just a single {@link VariableDeclarationFragment}. |
| 224 | * ASTRewrite may ignore this property if necessary. |
| 225 | * </p> |
| 226 | * |
| 227 | * @param hasParentheses <code>true</code> if this lambda expression has parentheses around its parameters |
| 228 | * and <code>false</code> otherwise |
| 229 | */ |
| 230 | public void setParentheses(boolean hasParentheses) { |
| 231 | preValueChange(PARENTHESES_PROPERTY); |
| 232 | this.hasParentheses = hasParentheses; |
| 233 | postValueChange(PARENTHESES_PROPERTY); |
| 234 | } |
| 235 | |
| 236 | /** |
| 237 | * Returns the live ordered list of formal parameters of this lambda expression. |
| 238 | * Note that all elements must be of the same type, either |
| 239 | * <ul> |
| 240 | * <li>all {@link SingleVariableDeclaration} (explicit type), or</li> |
| 241 | * <li>all {@link VariableDeclarationFragment} (inferred type).</li> |
| 242 | * </ul> |
| 243 | * |
| 244 | * @return the live list of formal parameters of this lambda expression |
| 245 | * (element type: {@link VariableDeclaration}) |
| 246 | */ |
| 247 | public List parameters() { |
| 248 | return this.parameters; |
| 249 | } |
| 250 | |
| 251 | /** |
| 252 | * Returns the body of this lambda expression. |
| 253 | * |
| 254 | * @return the lambda expression body, which can be either a {@link Block} or an {@link Expression} |
| 255 | */ |
| 256 | public ASTNode getBody() { |
| 257 | if (this.body == null) { |
| 258 | // lazy init must be thread-safe for readers |
| 259 | synchronized (this) { |
| 260 | if (this.body == null) { |
| 261 | preLazyInit(); |
| 262 | this.body = new Block(this.ast); |
| 263 | postLazyInit(this.body, BODY_PROPERTY); |
| 264 | } |
| 265 | } |
| 266 | } |
| 267 | return this.body; |
| 268 | } |
| 269 | |
| 270 | /** |
| 271 | * Sets the body of this lambda expression. |
| 272 | * |
| 273 | * @param body a block node or an expression node |
| 274 | * @exception IllegalArgumentException if: |
| 275 | * <ul> |
| 276 | * <li>the node belongs to a different AST</li> |
| 277 | * <li>the node already has a parent</li> |
| 278 | * <li>a cycle in would be created</li> |
| 279 | * <li>body is neither a {@link Block} nor an {@link Expression}</li> |
| 280 | * </ul> |
| 281 | */ |
| 282 | public void setBody(ASTNode body) { |
| 283 | if (!(body instanceof Expression || body instanceof Block)) { |
| 284 | throw new IllegalArgumentException(); |
| 285 | } |
| 286 | ASTNode oldChild = this.body; |
| 287 | preReplaceChild(oldChild, body, BODY_PROPERTY); |
| 288 | this.body = body; |
| 289 | postReplaceChild(oldChild, body, BODY_PROPERTY); |
| 290 | } |
| 291 | |
| 292 | /** |
| 293 | * Resolves and returns the binding for the lambda expression |
| 294 | * <p> |
| 295 | * Note that bindings are generally unavailable unless requested when the |
| 296 | * AST is being built. |
| 297 | * </p> |
| 298 | * |
| 299 | * @return the binding, or <code>null</code> if the binding cannot be |
| 300 | * resolved |
| 301 | */ |
| 302 | public IMethodBinding resolveMethodBinding() { |
| 303 | return this.ast.getBindingResolver().resolveMethod(this); |
| 304 | } |
| 305 | |
| 306 | @Override |
| 307 | int memSize() { |
| 308 | return BASE_NODE_SIZE + 3 * 4; |
| 309 | } |
| 310 | |
| 311 | @Override |
| 312 | int treeSize() { |
| 313 | return |
| 314 | memSize() |
| 315 | + this.parameters.listSize() |
| 316 | + (this.body == null ? 0 : getBody().treeSize()); |
| 317 | } |
| 318 | } |
| 319 |
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