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
Contributors:
    IBM Corporation - initial API and implementation
/*******************************************************************************
 * 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
 *
 * 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).
SwitchExpression:
	switch ( Expression )
			{ { SwitchCase | Statement } }
SwitchCase:
	case [ Expression { , Expression } ]  { : | ->}
	default { : | ->}

SwitchCase nodes are treated as a kind of
Statement.
Since:
3.18
@noinstantiate
This class is not intended to be instantiated by clients.
@noreference
This method is not intended to be referenced by clients as it is a part of Java preview feature./**
 * Switch expression AST node type (added in JEP 325).
 * <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>.
 *
 * @since 3.18
 * @noinstantiate This class is not intended to be instantiated by clients.
 * @noreference This method is not intended to be referenced by clients as it is a part of Java preview feature.
 */
@SuppressWarnings({"rawtypes", "unchecked"})
public class SwitchExpression extends Expression {

	
The "expression" structural property of this node type (child type: Expression). 
Since:
3.16/**
	 * 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: Statement). 
Since:
3.16/**
	 * 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: StructuralPropertyDescriptor), or null if uninitialized. /**
	 * A list of property descriptors (element type:
	 * {@link StructuralPropertyDescriptor}),
	 * or null if uninitialized.
	 */
	private static final List PROPERTY_DESCRIPTORS;

	static {
		List propertyList = new ArrayList(3);
		createPropertyList(SwitchExpression.class, propertyList);
		addProperty(EXPRESSION_PROPERTY, propertyList);
		addProperty(STATEMENTS_PROPERTY, propertyList);
		PROPERTY_DESCRIPTORS = reapPropertyList(propertyList);
	}

	
Returns a list of structural property descriptors for this node type.
Clients must not modify the result.
Params:
apiLevel – the API level; one of the
AST.JLS* constants
Returns:
a list of property descriptors (element type: StructuralPropertyDescriptor)
Since:
3.16/**
	 * 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 propertyDescriptors(apiLevel, false);
	}
	
		
Returns a list of structural property descriptors for this node type.
Clients must not modify the result.
Params:
apiLevel – the API level; one of the
AST.JLS* constants
previewEnabled – previewEnabled flag
Returns:
a list of property descriptors (element type: StructuralPropertyDescriptor)
@noreference
This method is not intended to be referenced by clients.
Since:
3.20/**
	 * 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
	 * @param previewEnabled previewEnabled flag
	 * @return a list of property descriptors (element type:
	 * {@link StructuralPropertyDescriptor})
	 * @noreference This method is not intended to be referenced by clients.
	 * @since 3.20
	 */
	public static List propertyDescriptors(int apiLevel, boolean previewEnabled) {
		if (apiLevel == AST.JLS13_INTERNAL && previewEnabled) {
			return PROPERTY_DESCRIPTORS;
		}
		return null;
	}

	
The expression; lazily initialized; defaults to a unspecified, but legal,
expression.
/**
	 * The expression; lazily initialized; defaults to a unspecified, but legal,
	 * expression.
	 */
	private Expression expression = null;

	
The statements and SwitchCase nodes (element type: Statement). Defaults to an empty list. /**
	 * 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.

N.B. This constructor is package-private.

Params:
ast – the AST that is to own this node
Throws:
UnsupportedOperationException – if this operation is used other than JLS13
UnsupportedOperationException – if this expression is used with previewEnabled flag as false/**
	 * 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
	 * @exception UnsupportedOperationException if this operation is used other than JLS13
	 * @exception UnsupportedOperationException if this expression is used with previewEnabled flag as false
	 */
	SwitchExpression(AST ast) {
		super(ast);
		supportedOnlyIn13();
		unsupportedWithoutPreviewError();
	}

	@Override
	final List internalStructuralPropertiesForType(int apiLevel) {
		return propertyDescriptors(apiLevel);
	}
	
	@Override
	final List internalStructuralPropertiesForType(int apiLevel, boolean previewEnabled) {
		return propertyDescriptors(apiLevel, previewEnabled);
	}

	@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.
Returns:
the expression node/**
	 * 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.
Params:
expression – the new expression node
Throws:
IllegalArgumentException – if:

the node belongs to a different AST
the node already has a parent
a cycle in would be created
/**
	 * 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, SwitchCase nodes mark the start of
the switch groups.
Returns:
the live list of statement nodes (element type: Statement)/**
	 * 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();
	}
}