Java tutorial
/******************************************************************************* * Copyright (c) 2000, 2014 IBM Corporation and others. * * This program and the accompanying materials * are made available under the terms of the Eclipse Public License 2.0 * which accompanies this distribution, and is available at * https://www.eclipse.org/legal/epl-2.0/ * * SPDX-License-Identifier: EPL-2.0 * * Contributors: * IBM Corporation - initial API and implementation *******************************************************************************/ package org.eclipse.jdt.core.dom; import java.util.ArrayList; import java.util.Iterator; import java.util.List; /** * Single variable declaration AST node type. Single variable * declaration nodes are used in a limited number of places, including formal * parameter lists and catch clauses. They are not used for field declarations * and regular variable declaration statements. * <pre> * SingleVariableDeclaration: * { ExtendedModifier } Type {Annotation} [ <b>...</b> ] Identifier { Dimension } [ <b>=</b> Expression ] * </pre> * <p> * Note: There's currently no construct in the Java language that allows an initializer on a SingleVariableDeclaration. * </p> * * @since 2.0 * @noinstantiate This class is not intended to be instantiated by clients. */ @SuppressWarnings({ "rawtypes", "unchecked" }) public class SingleVariableDeclaration extends VariableDeclaration { /** * The "modifiers" structural property of this node type (type: {@link Integer}) (JLS2 API only). * @deprecated In the JLS3 API, this property is replaced by {@link #MODIFIERS2_PROPERTY}. * @since 3.0 */ public static final SimplePropertyDescriptor MODIFIERS_PROPERTY = new SimplePropertyDescriptor( SingleVariableDeclaration.class, "modifiers", int.class, MANDATORY); //$NON-NLS-1$ /** * The "modifiers" structural property of this node type (element type: {@link IExtendedModifier}) (added in JLS3 API). * @since 3.1 */ public static final ChildListPropertyDescriptor MODIFIERS2_PROPERTY = new ChildListPropertyDescriptor( SingleVariableDeclaration.class, "modifiers", IExtendedModifier.class, CYCLE_RISK); //$NON-NLS-1$ /** * The "type" structural property of this node type (child type: {@link Type}). * @since 3.0 */ public static final ChildPropertyDescriptor TYPE_PROPERTY = new ChildPropertyDescriptor( SingleVariableDeclaration.class, "type", Type.class, MANDATORY, NO_CYCLE_RISK); //$NON-NLS-1$ /** * The "varargsAnnotations" structural property of variable arguments of this node type (element type: {@link Annotation}) * (added in JLS8 API). * @since 3.10 */ public static final ChildListPropertyDescriptor VARARGS_ANNOTATIONS_PROPERTY = new ChildListPropertyDescriptor( SingleVariableDeclaration.class, "varargsAnnotations", Annotation.class, CYCLE_RISK); //$NON-NLS-1$ /** * The "varargs" structural property of this node type (type: {@link Boolean}) (added in JLS3 API). * @since 3.1 */ public static final SimplePropertyDescriptor VARARGS_PROPERTY = new SimplePropertyDescriptor( SingleVariableDeclaration.class, "varargs", boolean.class, MANDATORY); //$NON-NLS-1$ /** * The "name" structural property of this node type (child type: {@link SimpleName}). * @since 3.0 */ public static final ChildPropertyDescriptor NAME_PROPERTY = internalNamePropertyFactory( SingleVariableDeclaration.class); /** * The "extraDimensions" structural property of this node type (type: {@link Integer}) * (before JLS8 only). * * @since 3.0 * @deprecated In JLS8 and later, use {@link SingleVariableDeclaration#EXTRA_DIMENSIONS2_PROPERTY} instead. */ public static final SimplePropertyDescriptor EXTRA_DIMENSIONS_PROPERTY = internalExtraDimensionsPropertyFactory( SingleVariableDeclaration.class); /** * The "extraDimensions2" structural property of this node type (element type: {@link Dimension}) (added in JLS8 API). * @since 3.10 */ public static final ChildListPropertyDescriptor EXTRA_DIMENSIONS2_PROPERTY = internalExtraDimensions2PropertyFactory( SingleVariableDeclaration.class); /** * The "initializer" structural property of this node type (child type: {@link Expression}). * @since 3.0 */ public static final ChildPropertyDescriptor INITIALIZER_PROPERTY = internalInitializerPropertyFactory( SingleVariableDeclaration.class); /** * A list of property descriptors (element type: * {@link StructuralPropertyDescriptor}), * or null if uninitialized. * @since 3.0 */ private static final List PROPERTY_DESCRIPTORS_2_0; /** * A list of property descriptors (element type: * {@link StructuralPropertyDescriptor}), * or null if uninitialized. * @since 3.1 */ private static final List PROPERTY_DESCRIPTORS_3_0; /** * A list of property descriptors (element type: * {@link StructuralPropertyDescriptor}), * or null if uninitialized. * @since 3.10 */ private static final List PROPERTY_DESCRIPTORS_8_0; static { List propertyList = new ArrayList(6); createPropertyList(SingleVariableDeclaration.class, propertyList); addProperty(MODIFIERS_PROPERTY, propertyList); addProperty(TYPE_PROPERTY, propertyList); addProperty(NAME_PROPERTY, propertyList); addProperty(EXTRA_DIMENSIONS_PROPERTY, propertyList); addProperty(INITIALIZER_PROPERTY, propertyList); PROPERTY_DESCRIPTORS_2_0 = reapPropertyList(propertyList); propertyList = new ArrayList(7); createPropertyList(SingleVariableDeclaration.class, propertyList); addProperty(MODIFIERS2_PROPERTY, propertyList); addProperty(TYPE_PROPERTY, propertyList); addProperty(VARARGS_PROPERTY, propertyList); addProperty(NAME_PROPERTY, propertyList); addProperty(EXTRA_DIMENSIONS_PROPERTY, propertyList); addProperty(INITIALIZER_PROPERTY, propertyList); PROPERTY_DESCRIPTORS_3_0 = reapPropertyList(propertyList); propertyList = new ArrayList(8); createPropertyList(SingleVariableDeclaration.class, propertyList); addProperty(MODIFIERS2_PROPERTY, propertyList); addProperty(TYPE_PROPERTY, propertyList); addProperty(VARARGS_ANNOTATIONS_PROPERTY, propertyList); addProperty(VARARGS_PROPERTY, propertyList); addProperty(NAME_PROPERTY, propertyList); addProperty(EXTRA_DIMENSIONS2_PROPERTY, propertyList); addProperty(INITIALIZER_PROPERTY, propertyList); PROPERTY_DESCRIPTORS_8_0 = reapPropertyList(propertyList); } /** * Returns a list of structural property descriptors for this node type. * Clients must not modify the result. * * @param apiLevel the API level; one of the * <code>AST.JLS*</code> constants * @return a list of property descriptors (element type: * {@link StructuralPropertyDescriptor}) * @since 3.0 */ public static List propertyDescriptors(int apiLevel) { if (apiLevel == AST.JLS2_INTERNAL) { return PROPERTY_DESCRIPTORS_2_0; } else if (apiLevel < AST.JLS8_INTERNAL) { return PROPERTY_DESCRIPTORS_3_0; } else { return PROPERTY_DESCRIPTORS_8_0; } } /** * The extended modifiers (element type: {@link IExtendedModifier}). * Null in JLS2. Added in JLS3; defaults to an empty list * (see constructor). * * @since 3.1 */ private ASTNode.NodeList modifiers = null; /** * The modifiers; bit-wise or of Modifier flags. * Defaults to none. Not used in 3.0. */ private int modifierFlags = Modifier.NONE; /** * The type; lazily initialized; defaults to an unspecified, * legal type. */ private Type type = null; /** * The type annotations on the varargs token (element type: {@link Annotation}). * Null before JLS8. Added in JLS8; defaults to an empty list * (see constructor). * * @since 3.10 */ private ASTNode.NodeList varargsAnnotations = null; /** * Indicates the last parameter of a variable arity method; * defaults to false. * * @since 3.1 */ private boolean variableArity = false; /** * Creates a new AST node for a variable declaration owned by the given * AST. By default, the variable declaration has: no modifiers, an * unspecified (but legal) type, an unspecified (but legal) variable name, * 0 dimensions after the variable; no initializer; not variable arity. * <p> * N.B. This constructor is package-private. * </p> * * @param ast the AST that is to own this node */ SingleVariableDeclaration(AST ast) { super(ast); if (ast.apiLevel >= AST.JLS3_INTERNAL) { this.modifiers = new ASTNode.NodeList(MODIFIERS2_PROPERTY); if (ast.apiLevel >= AST.JLS8_INTERNAL) { this.varargsAnnotations = new ASTNode.NodeList(VARARGS_ANNOTATIONS_PROPERTY); } } } @Override final ChildPropertyDescriptor internalNameProperty() { return NAME_PROPERTY; } @Override final SimplePropertyDescriptor internalExtraDimensionsProperty() { return EXTRA_DIMENSIONS_PROPERTY; } @Override final ChildListPropertyDescriptor internalExtraDimensions2Property() { return EXTRA_DIMENSIONS2_PROPERTY; } @Override final ChildPropertyDescriptor internalInitializerProperty() { return INITIALIZER_PROPERTY; } @Override final List internalStructuralPropertiesForType(int apiLevel) { return propertyDescriptors(apiLevel); } @Override final int internalGetSetIntProperty(SimplePropertyDescriptor property, boolean get, int value) { if (property == MODIFIERS_PROPERTY) { if (get) { return getModifiers(); } else { setModifiers(value); return 0; } } if (property == EXTRA_DIMENSIONS_PROPERTY) { if (get) { return getExtraDimensions(); } else { internalSetExtraDimensions(value); return 0; } } // allow default implementation to flag the error return super.internalGetSetIntProperty(property, get, value); } @Override final boolean internalGetSetBooleanProperty(SimplePropertyDescriptor property, boolean get, boolean value) { if (property == VARARGS_PROPERTY) { if (get) { return isVarargs(); } else { setVarargs(value); return false; } } // allow default implementation to flag the error return super.internalGetSetBooleanProperty(property, get, value); } @Override final ASTNode internalGetSetChildProperty(ChildPropertyDescriptor property, boolean get, ASTNode child) { if (property == TYPE_PROPERTY) { if (get) { return getType(); } else { setType((Type) child); return null; } } if (property == NAME_PROPERTY) { if (get) { return getName(); } else { setName((SimpleName) child); return null; } } if (property == INITIALIZER_PROPERTY) { if (get) { return getInitializer(); } else { setInitializer((Expression) child); return null; } } // allow default implementation to flag the error return super.internalGetSetChildProperty(property, get, child); } @Override final List internalGetChildListProperty(ChildListPropertyDescriptor property) { if (property == MODIFIERS2_PROPERTY) { return modifiers(); } if (property == VARARGS_ANNOTATIONS_PROPERTY) { return varargsAnnotations(); } if (property == EXTRA_DIMENSIONS2_PROPERTY) { return extraDimensions(); } // allow default implementation to flag the error return super.internalGetChildListProperty(property); } @Override final int getNodeType0() { return SINGLE_VARIABLE_DECLARATION; } @Override ASTNode clone0(AST target) { SingleVariableDeclaration result = new SingleVariableDeclaration(target); result.setSourceRange(getStartPosition(), getLength()); if (this.ast.apiLevel == AST.JLS2_INTERNAL) { result.setModifiers(getModifiers()); } else { result.modifiers().addAll(ASTNode.copySubtrees(target, modifiers())); result.setVarargs(isVarargs()); } result.setType((Type) getType().clone(target)); if (this.ast.apiLevel >= AST.JLS8_INTERNAL) { result.varargsAnnotations().addAll(ASTNode.copySubtrees(target, varargsAnnotations())); } result.setName((SimpleName) getName().clone(target)); if (this.ast.apiLevel >= AST.JLS8_INTERNAL) { result.extraDimensions().addAll(ASTNode.copySubtrees(target, this.extraDimensions())); } else { result.internalSetExtraDimensions(getExtraDimensions()); } result.setInitializer((Expression) ASTNode.copySubtree(target, getInitializer())); return result; } @Override final boolean subtreeMatch0(ASTMatcher matcher, Object other) { // dispatch to correct overloaded match method return matcher.match(this, other); } @Override void accept0(ASTVisitor visitor) { boolean visitChildren = visitor.visit(this); if (visitChildren) { // visit children in normal left to right reading order if (this.ast.apiLevel >= AST.JLS3_INTERNAL) { acceptChildren(visitor, this.modifiers); } acceptChild(visitor, getType()); if (this.ast.apiLevel >= AST.JLS8_INTERNAL && isVarargs()) { acceptChildren(visitor, this.varargsAnnotations); } acceptChild(visitor, getName()); if (this.ast.apiLevel >= AST.JLS8_INTERNAL) { acceptChildren(visitor, this.extraDimensions); } acceptChild(visitor, getInitializer()); } visitor.endVisit(this); } /** * Returns the live ordered list of modifiers and annotations * of this declaration (added in JLS3 API). * <p> * Note that the final modifier is the only meaningful modifier for local * variable and formal parameter declarations. * </p> * * @return the live list of modifiers and annotations * (element type: {@link IExtendedModifier}) * @exception UnsupportedOperationException if this operation is used in * a JLS2 AST * @since 3.1 */ public List modifiers() { // more efficient than just calling unsupportedIn2() to check if (this.modifiers == null) { unsupportedIn2(); } return this.modifiers; } /** * Returns the modifiers explicitly specified on this declaration. * <p> * In the JLS3 API, this method is a convenience method that * computes these flags from <code>modifiers()</code>. * </p> * * @return the bit-wise or of <code>Modifier</code> constants * @see Modifier */ public int getModifiers() { // more efficient than checking getAST().API_LEVEL if (this.modifiers == null) { // JLS2 behavior - bona fide property return this.modifierFlags; } else { // JLS3 behavior - convenient method // performance could be improved by caching computed flags // but this would require tracking changes to this.modifiers int computedModifierFlags = Modifier.NONE; for (Iterator it = modifiers().iterator(); it.hasNext();) { Object x = it.next(); if (x instanceof Modifier) { computedModifierFlags |= ((Modifier) x).getKeyword().toFlagValue(); } } return computedModifierFlags; } } /** * Sets the modifiers explicitly specified on this declaration (JLS2 API only). * <p> * The following modifiers are meaningful for fields: public, private, protected, * static, final, volatile, and transient. For local variable and formal * parameter declarations, the only meaningful modifier is final. * </p> * * @param modifiers the given modifiers (bit-wise or of <code>Modifier</code> constants) * @exception UnsupportedOperationException if this operation is used in * an AST later than JLS2 * @see Modifier * @deprecated In the JLS3 API, this method is replaced by * {@link #modifiers()} which contains a list of a <code>Modifier</code> nodes. */ public void setModifiers(int modifiers) { internalSetModifiers(modifiers); } /** * Internal synonym for deprecated method. Used to avoid * deprecation warnings. * @since 3.1 */ /*package*/ final void internalSetModifiers(int pmodifiers) { supportedOnlyIn2(); preValueChange(MODIFIERS_PROPERTY); this.modifierFlags = pmodifiers; postValueChange(MODIFIERS_PROPERTY); } /** * Returns the type of the variable declared in this variable declaration, * exclusive of any extra array dimensions or the varargs dimension. * <p> * WARNING: For array-typed varargs, the {@link Type#resolveBinding() binding} * of the returned <code>Type</code> is not useful, since it represents * an unused type. It misses the last (innermost) dimension that carries the * {@link #varargsAnnotations()}. * </p> * * @return the type */ public Type getType() { if (this.type == null) { // lazy init must be thread-safe for readers synchronized (this) { if (this.type == null) { preLazyInit(); this.type = this.ast.newPrimitiveType(PrimitiveType.INT); postLazyInit(this.type, TYPE_PROPERTY); } } } return this.type; } /** * Sets the type of the variable declared in this variable declaration to * the given type, exclusive of any extra array dimensions. * * @param type the new type * @exception IllegalArgumentException if: * <ul> * <li>the node belongs to a different AST</li> * <li>the node already has a parent</li> * </ul> */ public void setType(Type type) { if (type == null) { throw new IllegalArgumentException(); } ASTNode oldChild = this.type; preReplaceChild(oldChild, type, TYPE_PROPERTY); this.type = type; postReplaceChild(oldChild, type, TYPE_PROPERTY); } /** * Returns whether this declaration declares the last parameter of * a variable arity method (added in JLS3 API). * <p> * Note that the binding for the type <code>Foo</code> in the vararg method * declaration <code>void fun(Foo... args)</code> is always for the type as * written; i.e., the type binding for <code>Foo</code>. However, if you * navigate from the method declaration to its method binding to the * type binding for its last parameter, the type binding for the vararg * parameter is always an array type (i.e., <code>Foo[]</code>) reflecting * the way vararg methods get compiled. * </p> * <p> * WARNING: For array-typed varargs, the {@link Type#resolveBinding() binding} * of the variable's {@link #getType() type} is not useful, since it represents * an unused type. It misses the last (innermost) dimension that carries the * {@link #varargsAnnotations()}. * </p> * * @return <code>true</code> if this is a variable arity parameter declaration, * and <code>false</code> otherwise * @exception UnsupportedOperationException if this operation is used in * a JLS2 AST * @since 3.1 */ public boolean isVarargs() { // more efficient than just calling unsupportedIn2() to check if (this.modifiers == null) { unsupportedIn2(); } return this.variableArity; } /** * Sets whether this declaration declares the last parameter of * a variable arity method (added in JLS3 API). * * @param variableArity <code>true</code> if this is a variable arity * parameter declaration, and <code>false</code> otherwise * @since 3.1 */ public void setVarargs(boolean variableArity) { // more efficient than just calling unsupportedIn2() to check if (this.modifiers == null) { unsupportedIn2(); } preValueChange(VARARGS_PROPERTY); this.variableArity = variableArity; postValueChange(VARARGS_PROPERTY); } /** * Returns the ordered list of annotations on the varargs token (added in JLS8 API). * <p> * WARNING: For array-typed varargs, the {@link Type#resolveBinding() binding} * of the variable's {@link #getType() type} is not useful, since it represents * an unused type. It misses the last (innermost) dimension that carries the * returned {@code varargsAnnotations}. * </p> * * @return the list of annotations on the varargs token (element type: {@link Annotation}) * @exception UnsupportedOperationException if this operation is used * in a JLS2, JLS3 or JLS4 AST * @see #isVarargs() * @since 3.10 */ public List varargsAnnotations() { if (this.varargsAnnotations == null) { unsupportedIn2_3_4(); } return this.varargsAnnotations; } @Override int memSize() { // treat Operator as free return BASE_NODE_SIZE + 9 * 4; } @Override int treeSize() { return memSize() + (this.modifiers == null ? 0 : this.modifiers.listSize()) + (this.type == null ? 0 : getType().treeSize()) + (this.varargsAnnotations == null ? 0 : this.varargsAnnotations.listSize()) + (this.variableName == null ? 0 : getName().treeSize()) + (this.extraDimensions == null ? 0 : this.extraDimensions.listSize()) + (this.optionalInitializer == null ? 0 : getInitializer().treeSize()); } }