Java tutorial
/******************************************************************************* * Copyright (c) 2000, 2013 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.List; /** * Conditional expression AST node type. * * <pre> * ConditionalExpression: * Expression <b>?</b> Expression <b>:</b> Expression * </pre> * * @since 2.0 * @noinstantiate This class is not intended to be instantiated by clients. */ @SuppressWarnings("rawtypes") public class ConditionalExpression extends Expression { /** * The "expression" structural property of this node type (child type: {@link Expression}). * @since 3.0 */ public static final ChildPropertyDescriptor EXPRESSION_PROPERTY = new ChildPropertyDescriptor( ConditionalExpression.class, "expression", Expression.class, MANDATORY, CYCLE_RISK); //$NON-NLS-1$ /** * The "thenExpression" structural property of this node type (child type: {@link Expression}). * @since 3.0 */ public static final ChildPropertyDescriptor THEN_EXPRESSION_PROPERTY = new ChildPropertyDescriptor( ConditionalExpression.class, "thenExpression", Expression.class, MANDATORY, CYCLE_RISK); //$NON-NLS-1$ /** * The "elseExpression" structural property of this node type (child type: {@link Expression}). * @since 3.0 */ public static final ChildPropertyDescriptor ELSE_EXPRESSION_PROPERTY = new ChildPropertyDescriptor( ConditionalExpression.class, "elseExpression", Expression.class, MANDATORY, CYCLE_RISK); //$NON-NLS-1$ /** * A list of property descriptors (element type: * {@link StructuralPropertyDescriptor}), * or null if uninitialized. */ private static final List PROPERTY_DESCRIPTORS; static { List properyList = new ArrayList(4); createPropertyList(ConditionalExpression.class, properyList); addProperty(EXPRESSION_PROPERTY, properyList); addProperty(THEN_EXPRESSION_PROPERTY, properyList); addProperty(ELSE_EXPRESSION_PROPERTY, properyList); PROPERTY_DESCRIPTORS = reapPropertyList(properyList); } /** * 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) { return PROPERTY_DESCRIPTORS; } /** * The condition expression; lazily initialized; defaults to an unspecified, * but legal, expression. */ private Expression conditionExpression = null; /** * The "then" expression; lazily initialized; defaults to an unspecified, * but legal, expression. */ private Expression thenExpression = null; /** * The "else" expression; lazily initialized; defaults to an unspecified, * but legal, expression. */ private Expression elseExpression = null; /** * Creates a new unparented conditional expression node owned by the given * AST. By default, the condition, "then", and "else" expresssions are * unspecified, but legal. * <p> * N.B. This constructor is package-private. * </p> * * @param ast the AST that is to own this node */ ConditionalExpression(AST ast) { super(ast); } @Override final List internalStructuralPropertiesForType(int apiLevel) { return propertyDescriptors(apiLevel); } @Override final ASTNode internalGetSetChildProperty(ChildPropertyDescriptor property, boolean get, ASTNode child) { if (property == EXPRESSION_PROPERTY) { if (get) { return getExpression(); } else { setExpression((Expression) child); return null; } } if (property == THEN_EXPRESSION_PROPERTY) { if (get) { return getThenExpression(); } else { setThenExpression((Expression) child); return null; } } if (property == ELSE_EXPRESSION_PROPERTY) { if (get) { return getElseExpression(); } else { setElseExpression((Expression) child); return null; } } // allow default implementation to flag the error return super.internalGetSetChildProperty(property, get, child); } @Override final int getNodeType0() { return CONDITIONAL_EXPRESSION; } @Override ASTNode clone0(AST target) { ConditionalExpression result = new ConditionalExpression(target); result.setSourceRange(getStartPosition(), getLength()); result.setExpression((Expression) getExpression().clone(target)); result.setThenExpression((Expression) getThenExpression().clone(target)); result.setElseExpression((Expression) getElseExpression().clone(target)); 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 acceptChild(visitor, getExpression()); acceptChild(visitor, getThenExpression()); acceptChild(visitor, getElseExpression()); } visitor.endVisit(this); } /** * Returns the condition of this conditional expression. * * @return the condition node */ public Expression getExpression() { if (this.conditionExpression == null) { // lazy init must be thread-safe for readers synchronized (this) { if (this.conditionExpression == null) { preLazyInit(); this.conditionExpression = new SimpleName(this.ast); postLazyInit(this.conditionExpression, EXPRESSION_PROPERTY); } } } return this.conditionExpression; } /** * Sets the condition of this conditional expression. * * @param expression the condition node * @exception IllegalArgumentException if: * <ul> * <li>the node belongs to a different AST</li> * <li>the node already has a parent</li> * <li>a cycle in would be created</li> * </ul> */ public void setExpression(Expression expression) { if (expression == null) { throw new IllegalArgumentException(); } ASTNode oldChild = this.conditionExpression; preReplaceChild(oldChild, expression, EXPRESSION_PROPERTY); this.conditionExpression = expression; postReplaceChild(oldChild, expression, EXPRESSION_PROPERTY); } /** * Returns the "then" part of this conditional expression. * * @return the "then" expression node */ public Expression getThenExpression() { if (this.thenExpression == null) { // lazy init must be thread-safe for readers synchronized (this) { if (this.thenExpression == null) { preLazyInit(); this.thenExpression = new SimpleName(this.ast); postLazyInit(this.thenExpression, THEN_EXPRESSION_PROPERTY); } } } return this.thenExpression; } /** * Sets the "then" part of this conditional expression. * * @param expression the "then" expression node * @exception IllegalArgumentException if: * <ul> * <li>the node belongs to a different AST</li> * <li>the node already has a parent</li> * <li>a cycle in would be created</li> * </ul> */ public void setThenExpression(Expression expression) { if (expression == null) { throw new IllegalArgumentException(); } ASTNode oldChild = this.thenExpression; preReplaceChild(oldChild, expression, THEN_EXPRESSION_PROPERTY); this.thenExpression = expression; postReplaceChild(oldChild, expression, THEN_EXPRESSION_PROPERTY); } /** * Returns the "else" part of this conditional expression. * * @return the "else" expression node */ public Expression getElseExpression() { if (this.elseExpression == null) { // lazy init must be thread-safe for readers synchronized (this) { if (this.elseExpression == null) { preLazyInit(); this.elseExpression = new SimpleName(this.ast); postLazyInit(this.elseExpression, ELSE_EXPRESSION_PROPERTY); } } } return this.elseExpression; } /** * Sets the "else" part of this conditional expression. * * @param expression the "else" expression node * @exception IllegalArgumentException if: * <ul> * <li>the node belongs to a different AST</li> * <li>the node already has a parent</li> * <li>a cycle in would be created</li> * </ul> */ public void setElseExpression(Expression expression) { if (expression == null) { throw new IllegalArgumentException(); } ASTNode oldChild = this.elseExpression; preReplaceChild(oldChild, expression, ELSE_EXPRESSION_PROPERTY); this.elseExpression = expression; postReplaceChild(oldChild, expression, ELSE_EXPRESSION_PROPERTY); } @Override int memSize() { // treat Code as free return BASE_NODE_SIZE + 3 * 4; } @Override int treeSize() { return memSize() + (this.conditionExpression == null ? 0 : getExpression().treeSize()) + (this.thenExpression == null ? 0 : getThenExpression().treeSize()) + (this.elseExpression == null ? 0 : getElseExpression().treeSize()); } }