| /******************************************************************************* |
| * Copyright (c) 2000, 2013 IBM Corporation and others. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-v10.html |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| |
| package org.eclipse.jdt.core.dom; |
| |
| /** |
| * Abstract base class of AST nodes that represent expressions. |
| * There are several kinds of expressions. |
| * <p> |
| * <pre> |
| * Expression: |
| * {@link Annotation}, |
| * {@link ArrayAccess}, |
| * {@link ArrayCreation}, |
| * {@link ArrayInitializer}, |
| * {@link Assignment}, |
| * {@link BooleanLiteral}, |
| * {@link CastExpression}, |
| * {@link CharacterLiteral}, |
| * {@link ClassInstanceCreation}, |
| * {@link ConditionalExpression}, |
| * {@link CreationReference}, |
| * {@link ExpressionMethodReference}, |
| * {@link FieldAccess}, |
| * {@link InfixExpression}, |
| * {@link InstanceofExpression}, |
| * {@link LambdaExpression}, |
| * {@link MethodInvocation}, |
| * {@link MethodReference}, |
| * {@link Name}, |
| * {@link NullLiteral}, |
| * {@link NumberLiteral}, |
| * {@link ParenthesizedExpression}, |
| * {@link PostfixExpression}, |
| * {@link PrefixExpression}, |
| * {@link StringLiteral}, |
| * {@link SuperFieldAccess}, |
| * {@link SuperMethodInvocation}, |
| * {@link SuperMethodReference}, |
| * {@link ThisExpression}, |
| * {@link TypeLiteral}, |
| * {@link TypeMethodReference}, |
| * {@link VariableDeclarationExpression} |
| * </pre> |
| * </p> |
| * |
| * @since 2.0 |
| */ |
| public abstract class Expression extends ASTNode { |
| |
| /** |
| * Creates a new AST node for an expression owned by the given AST. |
| * <p> |
| * N.B. This constructor is package-private. |
| * </p> |
| * |
| * @param ast the AST that is to own this node |
| */ |
| Expression(AST ast) { |
| super(ast); |
| } |
| |
| /** |
| * Resolves and returns the compile-time constant expression value as |
| * specified in JLS2 15.28, if this expression has one. Constant expression |
| * values are unavailable unless bindings are requested when the AST is |
| * being built. If the type of the value is a primitive type, the result |
| * is the boxed equivalent (i.e., int returned as an <code>Integer</code>); |
| * if the type of the value is <code>String</code>, the result is the string |
| * itself. If the expression does not have a compile-time constant expression |
| * value, the result is <code>null</code>. |
| * <p> |
| * Resolving constant expressions takes into account the value of simple |
| * and qualified names that refer to constant variables (JLS2 4.12.4). |
| * </p> |
| * <p> |
| * Note 1: enum constants are not considered constant expressions. |
| * The result is always <code>null</code> for these. |
| * </p> |
| * <p> |
| * Note 2: Compile-time constant expressions cannot denote <code>null</code>. |
| * So technically {@link NullLiteral} nodes are not constant expressions. |
| * The result is <code>null</code> for these nonetheless. |
| * </p> |
| * |
| * @return the constant expression value, or <code>null</code> if this |
| * expression has no constant expression value or if bindings were not |
| * requested when the AST was created |
| * @since 3.1 |
| */ |
| public final Object resolveConstantExpressionValue() { |
| return this.ast.getBindingResolver().resolveConstantExpressionValue(this); |
| } |
| |
| /** |
| * Resolves and returns the binding for the type of this expression. |
| * <p> |
| * Note that bindings are generally unavailable unless requested when the |
| * AST is being built. |
| * </p> |
| * |
| * @return the binding for the type of this expression, or |
| * <code>null</code> if the type cannot be resolved |
| */ |
| public final ITypeBinding resolveTypeBinding() { |
| return this.ast.getBindingResolver().resolveExpressionType(this); |
| } |
| |
| /** |
| * Returns whether this expression node is the site of a boxing |
| * conversion (JLS3 5.1.7). This information is available only |
| * when bindings are requested when the AST is being built. |
| * |
| * @return <code>true</code> if this expression is the site of a |
| * boxing conversion, or <code>false</code> if either no boxing conversion |
| * is involved or if bindings were not requested when the AST was created |
| * @since 3.1 |
| */ |
| public final boolean resolveBoxing() { |
| return this.ast.getBindingResolver().resolveBoxing(this); |
| } |
| |
| /** |
| * Returns whether this expression node is the site of an unboxing |
| * conversion (JLS3 5.1.8). This information is available only |
| * when bindings are requested when the AST is being built. |
| * |
| * @return <code>true</code> if this expression is the site of an |
| * unboxing conversion, or <code>false</code> if either no unboxing |
| * conversion is involved or if bindings were not requested when the |
| * AST was created |
| * @since 3.1 |
| */ |
| public final boolean resolveUnboxing() { |
| return this.ast.getBindingResolver().resolveUnboxing(this); |
| } |
| } |
| |