/*******************************************************************************
* Copyright (c) 2019 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
*
* This is an implementation of an early-draft specification developed under the Java
* Community Process (JCP) and is made available for testing and evaluation purposes
* only. The code is not compatible with any specification of the JCP.
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.jdt.core.dom;
import java.util.ArrayList;
import java.util.List;
/**
* Switch expression AST node type (added in JEP 325).
* <p>
* <pre>
* SwitchExpression:
* <b>switch</b> <b>(</b> Expression <b>)</b>
* <b>{</b> { SwitchCase | Statement } <b>}</b>
* SwitchCase:
* <b>case</b> [ Expression { <b>,</b> Expression } ] <b>{ : | ->}</b>
* <b>default</b> <b>{ : | ->}</b>
* </pre>
* <code>SwitchCase</code> nodes are treated as a kind of
* <code>Statement</code>.
* </p>
*
* @since 3.17 BETA_JAVA_12
* @noinstantiate This class is not intended to be instantiated by clients.
*/
@SuppressWarnings({"rawtypes", "unchecked"})
public class SwitchExpression extends Expression {
/**
* The "expression" structural property of this node type (child type: {@link Expression}).
* @since 3.16
*/
public static final ChildPropertyDescriptor EXPRESSION_PROPERTY =
new ChildPropertyDescriptor(SwitchExpression.class, "expression", Expression.class, MANDATORY, CYCLE_RISK); //$NON-NLS-1$
/**
* The "statements" structural property of this node type (element type: {@link Statement}).
* @since 3.16
*/
public static final ChildListPropertyDescriptor STATEMENTS_PROPERTY =
new ChildListPropertyDescriptor(SwitchExpression.class, "statements", Statement.class, CYCLE_RISK); //$NON-NLS-1$
/**
* A list of property descriptors (element type:
* {@link StructuralPropertyDescriptor}),
* or null if uninitialized.
*/
private static final List PROPERTY_DESCRIPTORS_12_0;
static {
List propertyList = new ArrayList(3);
createPropertyList(SwitchExpression.class, propertyList);
addProperty(EXPRESSION_PROPERTY, propertyList);
addProperty(STATEMENTS_PROPERTY, propertyList);
PROPERTY_DESCRIPTORS_12_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 3.16
*/
public static List propertyDescriptors(int apiLevel) {
return PROPERTY_DESCRIPTORS_12_0;
}
/**
* The expression; lazily initialized; defaults to a unspecified, but legal,
* expression.
*/
private Expression expression = null;
/**
* The statements and SwitchCase nodes
* (element type: {@link Statement}).
* Defaults to an empty list.
*/
private ASTNode.NodeList statements =
new ASTNode.NodeList(STATEMENTS_PROPERTY);
/**
* Creates a new unparented switch statement node owned by the given
* AST. By default, the swicth statement has an unspecified, but legal,
* expression, and an empty list of switch groups.
* <p>
* N.B. This constructor is package-private.
* </p>
*
* @param ast the AST that is to own this node
*/
SwitchExpression(AST ast) {
super(ast);
unsupportedBelow12();
}
@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;
}
}
// allow default implementation to flag the error
return super.internalGetSetChildProperty(property, get, child);
}
@Override
final List internalGetChildListProperty(ChildListPropertyDescriptor property) {
if (property == STATEMENTS_PROPERTY) {
return statements();
}
// allow default implementation to flag the error
return super.internalGetChildListProperty(property);
}
@Override
final int getNodeType0() {
return SWITCH_EXPRESSION;
}
@Override
ASTNode clone0(AST target) {
SwitchExpression result = new SwitchExpression(target);
result.setSourceRange(getStartPosition(), getLength());
result.setExpression((Expression) getExpression().clone(target));
result.statements().addAll(ASTNode.copySubtrees(target, statements()));
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());
acceptChildren(visitor, this.statements);
}
visitor.endVisit(this);
}
/**
* Returns the expression of this switch statement.
*
* @return the expression node
*/
public Expression getExpression() {
if (this.expression == null) {
// lazy init must be thread-safe for readers
synchronized (this) {
if (this.expression == null) {
preLazyInit();
this.expression = new SimpleName(this.ast);
postLazyInit(this.expression, EXPRESSION_PROPERTY);
}
}
}
return this.expression;
}
/**
* Sets the expression of this switch statement.
*
* @param expression the new 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 setExpression(Expression expression) {
if (expression == null) {
throw new IllegalArgumentException();
}
ASTNode oldChild = this.expression;
preReplaceChild(oldChild, expression, EXPRESSION_PROPERTY);
this.expression = expression;
postReplaceChild(oldChild, expression, EXPRESSION_PROPERTY);
}
/**
* Returns the live ordered list of statements for this switch statement.
* Within this list, <code>SwitchCase</code> nodes mark the start of
* the switch groups.
*
* @return the live list of statement nodes
* (element type: {@link Statement})
*/
public List statements() {
return this.statements;
}
@Override
int memSize() {
return BASE_NODE_SIZE + 3 * 4;
}
@Override
int treeSize() {
return
memSize()
+ (this.expression == null ? 0 : getExpression().treeSize())
+ this.statements.listSize();
}
}
