NameExpr.java
/*
* Copyright (C) 2007-2010 J��lio Vilmar Gesser.
* Copyright (C) 2011, 2013-2026 The JavaParser Team.
*
* This file is part of JavaParser.
*
* JavaParser can be used either under the terms of
* a) the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
* b) the terms of the Apache License
*
* You should have received a copy of both licenses in LICENCE.LGPL and
* LICENCE.APACHE. Please refer to those files for details.
*
* JavaParser is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*/
package com.github.javaparser.ast.expr;
import static com.github.javaparser.utils.Utils.assertNotNull;
import com.github.javaparser.TokenRange;
import com.github.javaparser.ast.AllFieldsConstructor;
import com.github.javaparser.ast.Generated;
import com.github.javaparser.ast.Node;
import com.github.javaparser.ast.nodeTypes.NodeWithSimpleName;
import com.github.javaparser.ast.observer.ObservableProperty;
import com.github.javaparser.ast.stmt.ExplicitConstructorInvocationStmt;
import com.github.javaparser.ast.visitor.CloneVisitor;
import com.github.javaparser.ast.visitor.GenericVisitor;
import com.github.javaparser.ast.visitor.VoidVisitor;
import com.github.javaparser.metamodel.JavaParserMetaModel;
import com.github.javaparser.metamodel.NameExprMetaModel;
import com.github.javaparser.resolution.Resolvable;
import com.github.javaparser.resolution.UnsolvedSymbolException;
import com.github.javaparser.resolution.declarations.ResolvedDeclaration;
import com.github.javaparser.resolution.declarations.ResolvedTypeDeclaration;
import com.github.javaparser.resolution.declarations.ResolvedValueDeclaration;
import java.util.Optional;
import java.util.function.Consumer;
/**
* Whenever a SimpleName is used in an expression, it is wrapped in NameExpr.
* <br>In {@code int x = a + 3;} a is a SimpleName inside a NameExpr.
*
* @author Julio Vilmar Gesser
*/
/**
* BREAKING CHANGE (introduced to fix issue #2684):
* This class previously implemented {@code Resolvable<ResolvedValueDeclaration>}, implying that
* every {@code NameExpr} denotes a value. That assumption is incorrect per JLS ��6.5: a simple
* name is contextually ambiguous and may denote either a <em>value</em> (variable, field,
* parameter) or a <em>type</em> (class, interface, enum), depending on where it appears in the
* source code.
*
* <p>The type parameter has been widened to {@code ResolvedDeclaration}, the common supertype
* of both {@link ResolvedValueDeclaration} and {@link ResolvedTypeDeclaration}, so that
* {@link #resolve()} can return the correct kind of declaration without throwing for type-denoting
* names such as {@code System} in {@code System.out.println()}.
*
* <p><b>Migration guide for existing callers of {@code resolve()}:</b>
* <ul>
* <li>If you know the name is a value (variable, field, parameter), cast the result:
* {@code (ResolvedValueDeclaration) nameExpr.resolve()} ��� or check first with
* {@code !decl.isType()}.</li>
* <li>If you know the name is a type, cast to {@link ResolvedTypeDeclaration} and verify
* with {@code decl.isType()}.</li>
* <li>If the kind is unknown (e.g., when iterating all {@code NameExpr} nodes), branch on
* {@code decl.isType()} before casting.</li>
* </ul>
*/
public class NameExpr extends Expression implements NodeWithSimpleName<NameExpr>, Resolvable<ResolvedDeclaration> {
private SimpleName name;
public NameExpr() {
this(null, new SimpleName());
}
public NameExpr(final String name) {
this(null, new SimpleName(name));
}
@AllFieldsConstructor
public NameExpr(final SimpleName name) {
this(name.getTokenRange().orElse(null), name);
setRange(name.getRange().orElse(null));
}
/**
* This constructor is used by the parser and is considered private.
*/
@Generated("com.github.javaparser.generator.core.node.MainConstructorGenerator")
public NameExpr(TokenRange tokenRange, SimpleName name) {
super(tokenRange);
setName(name);
customInitialization();
}
@Override
@Generated("com.github.javaparser.generator.core.node.AcceptGenerator")
public <R, A> R accept(final GenericVisitor<R, A> v, final A arg) {
return v.visit(this, arg);
}
@Override
@Generated("com.github.javaparser.generator.core.node.AcceptGenerator")
public <A> void accept(final VoidVisitor<A> v, final A arg) {
v.visit(this, arg);
}
@Generated("com.github.javaparser.generator.core.node.PropertyGenerator")
public SimpleName getName() {
return name;
}
@Generated("com.github.javaparser.generator.core.node.PropertyGenerator")
public NameExpr setName(final SimpleName name) {
assertNotNull(name);
if (name == this.name) {
return this;
}
notifyPropertyChange(ObservableProperty.NAME, this.name, name);
if (this.name != null) this.name.setParentNode(null);
this.name = name;
setAsParentNodeOf(name);
return this;
}
@Override
@Generated("com.github.javaparser.generator.core.node.CloneGenerator")
public NameExpr clone() {
return (NameExpr) accept(new CloneVisitor(), null);
}
@Override
@Generated("com.github.javaparser.generator.core.node.GetMetaModelGenerator")
public NameExprMetaModel getMetaModel() {
return JavaParserMetaModel.nameExprMetaModel;
}
@Override
@Generated("com.github.javaparser.generator.core.node.ReplaceMethodGenerator")
public boolean replace(Node node, Node replacementNode) {
if (node == null) {
return false;
}
if (node == name) {
setName((SimpleName) replacementNode);
return true;
}
return super.replace(node, replacementNode);
}
@Override
@Generated("com.github.javaparser.generator.core.node.TypeCastingGenerator")
public boolean isNameExpr() {
return true;
}
@Override
@Generated("com.github.javaparser.generator.core.node.TypeCastingGenerator")
public NameExpr asNameExpr() {
return this;
}
@Override
@Generated("com.github.javaparser.generator.core.node.TypeCastingGenerator")
public void ifNameExpr(Consumer<NameExpr> action) {
action.accept(this);
}
/**
* Resolves the declaration corresponding to this name expression.
*
* <p>A {@code NameExpr} is contextually ambiguous per JLS ��6.5: the same syntactic construct
* may denote either a <em>value</em> (variable, field, parameter, enum constant) or a
* <em>type</em> (class, interface, enum), depending on where it appears in the source code.
* Examples:
* <ul>
* <li>{@code count} in {@code count + 1} is a value name ��� resolves to a
* {@link ResolvedValueDeclaration}.</li>
* <li>{@code System} in {@code System.out.println()} is a type name ��� resolves to a
* {@link ResolvedTypeDeclaration}.</li>
* </ul>
*
* <p>The return type is {@link ResolvedDeclaration}, the common supertype of both
* {@link ResolvedValueDeclaration} and {@link ResolvedTypeDeclaration}. Use
* {@link ResolvedDeclaration#isType()} on the result to determine the actual kind, then
* cast accordingly:
* <pre>{@code
* ResolvedDeclaration decl = nameExpr.resolve();
* if (decl.isType()) {
* ResolvedTypeDeclaration typeDecl = (ResolvedTypeDeclaration) decl;
* } else {
* ResolvedValueDeclaration valueDecl = (ResolvedValueDeclaration) decl;
* }
* }</pre>
*
* <p><b>Note for existing callers (breaking change from prior versions):</b> this method
* previously returned {@link ResolvedValueDeclaration}. Code that assigns the result to a
* {@code ResolvedValueDeclaration} variable must either widen the variable type to
* {@link ResolvedDeclaration} or add a cast for the value case.
*
* @return a {@link ResolvedDeclaration} ��� either a {@link ResolvedValueDeclaration} for
* value-denoting names or a {@link ResolvedTypeDeclaration} for type-denoting names.
* @throws UnsolvedSymbolException if the name cannot be resolved as a value or as a type.
* @see FieldAccessExpr#resolve()
* @see MethodCallExpr#resolve()
* @see ObjectCreationExpr#resolve()
* @see ExplicitConstructorInvocationStmt#resolve()
*/
@Override
public ResolvedDeclaration resolve() {
return getSymbolResolver().resolveDeclaration(this, ResolvedDeclaration.class);
}
@Override
@Generated("com.github.javaparser.generator.core.node.TypeCastingGenerator")
public Optional<NameExpr> toNameExpr() {
return Optional.of(this);
}
}