Copyright (c) 2000, 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) 2000, 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 case AST node type. A switch case is a special kind of node used only
in switch statements. It is a Statement in name only.
SwitchCase:
		case Expression  :
		default :
Switch case allows multiple expressions and '->' as part of Java 12 preview feature (JEP 325)
	case [ Expression { , Expression } ]  { : | ->}
	default { : | ->}

Since:
2.0
@noinstantiate
This class is not intended to be instantiated by clients./**
 * Switch case AST node type. A switch case is a special kind of node used only
 * in switch statements. It is a <code>Statement</code> in name only.
 * <pre>
 * SwitchCase:
 * 		<b>case</b> Expression  <b>:</b>
 * 		<b>default</b> <b>:</b>
 * 
 * Switch case allows multiple expressions and '->' as part of Java 12 preview feature (JEP 325)
 *		<b>case</b> [ Expression { <b>,</b> Expression } ]  <b>{ : | ->}</b>
 *		<b>default</b> <b>{ : | ->}</b>
 * </pre>
 *
 * @since 2.0
 * @noinstantiate This class is not intended to be instantiated by clients.
 */
@SuppressWarnings("rawtypes")
public class SwitchCase extends Statement {

	
The "expression" structural property of this node type (child type: Expression). 
Since:
3.0
Deprecated:
In the JLS 12 15.28.1 API, this property is replaced by EXPRESSIONS2_PROPERTY./**
	 * The "expression" structural property of this node type (child type: {@link Expression}).
	 * @since 3.0
	 * @deprecated In the JLS 12 15.28.1 API, this property is replaced by {@link #EXPRESSIONS2_PROPERTY }.
	 */
	public static final ChildPropertyDescriptor EXPRESSION_PROPERTY =
		new ChildPropertyDescriptor(SwitchCase.class, "expression", Expression.class, OPTIONAL, CYCLE_RISK); //$NON-NLS-1$

	
The "expression" structural property of this node type (child type: Expression). (added in JEP 325). 
@noreference
This property is not intended to be referenced by clients as it is a part of Java preview feature.
Since:
3.18/**
	 * The "expression" structural property of this node type (child type: {@link Expression}). (added in JEP 325).
	 * @noreference This property is not intended to be referenced by clients as it is a part of Java preview feature.
	 * @since 3.18
	 */
	public static final ChildListPropertyDescriptor EXPRESSIONS2_PROPERTY  =
			new ChildListPropertyDescriptor(SwitchCase.class, "expression", Expression.class, CYCLE_RISK); //$NON-NLS-1$);
	
	
The "switchLabeledRule" structural property of this node type (type: Boolean). 
@noreference
This property is not intended to be referenced by clients as it is a part of Java preview feature.
Since:
3.18/**
	 * The "switchLabeledRule" structural property of this node type (type: {@link Boolean}).
	 * @noreference This property is not intended to be referenced by clients as it is a part of Java preview feature.
	 * @since 3.18
	 */
	public static final SimplePropertyDescriptor SWITCH_LABELED_RULE_PROPERTY =
		new SimplePropertyDescriptor(SwitchCase.class, "switchLabeledRule", boolean.class, MANDATORY); //$NON-NLS-1$
	
	
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;
	
	
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_13;

	static {
		List propertyList = new ArrayList(2);
		createPropertyList(SwitchCase.class, propertyList);
		addProperty(EXPRESSION_PROPERTY, propertyList);
		PROPERTY_DESCRIPTORS = reapPropertyList(propertyList);
		
		propertyList = new ArrayList(2);
		createPropertyList(SwitchCase.class, propertyList);
		addProperty(EXPRESSIONS2_PROPERTY , propertyList);
		addProperty(SWITCH_LABELED_RULE_PROPERTY, propertyList);
		PROPERTY_DESCRIPTORS_13 = 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:
3.0/**
	 * 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 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 – the previewEnabled flag
Returns:
a list of property descriptors (element type: StructuralPropertyDescriptor)
@noreference
This method is not intended to be referenced by clients.
Since:
3.19/**
	 * 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 the previewEnabled flag
	 * @return a list of property descriptors (element type:
	 * {@link StructuralPropertyDescriptor})
	 * @noreference This method is not intended to be referenced by clients.
	 * @since 3.19
	 */
	public static List propertyDescriptors(int apiLevel, boolean previewEnabled) {
		if (apiLevel == AST.JLS13_INTERNAL && previewEnabled) {
			return PROPERTY_DESCRIPTORS_13;
		}
		return PROPERTY_DESCRIPTORS;
	}

	
The expression; null for none; lazily initialized (but
does not default to none).
See Also:
expressionInitialized/**
	 * The expression; <code>null</code> for none; lazily initialized (but
	 * does <b>not</b> default to none).
	 * @see #expressionInitialized
	 */
	private Expression optionalExpression = null;
	
	
true indicates "->" and false indicates ":".
/**
	 * <code>true</code> indicates "->" and <code>false</code> indicates ":".
	 */
	private boolean switchLabeledRule = false;

	
	
The expression list; empty for none; 
/**
	 * The expression list; <code>empty</code> for none; 
	 */
	private ASTNode.NodeList expressions = null;

	
Indicates whether optionalExpression has been initialized.
/**
	 * Indicates whether <code>optionalExpression</code> has been initialized.
	 */
	private boolean expressionInitialized = false;

	
Creates a new AST node for a switch case pseudo-statement owned by the
given AST. By default, there is no expression, but legal, and switchLabeledRule
is false which indicates ":".
Params:
ast – the AST that is to own this node/**
	 * Creates a new AST node for a switch case pseudo-statement owned by the
	 * given AST. By default, there is no expression, but legal, and switchLabeledRule
	 * is false which indicates ":".
	 *
	 * @param ast the AST that is to own this node
	 */
	SwitchCase(AST ast) {
		super(ast);
		if (ast.isPreviewEnabled()) {
			this.expressions = new ASTNode.NodeList(EXPRESSIONS2_PROPERTY );
		}
	}

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

	@Override
	final boolean internalGetSetBooleanProperty(SimplePropertyDescriptor property, boolean get, boolean value) {
		if (property == SWITCH_LABELED_RULE_PROPERTY) {
			if (get) {
				return isSwitchLabeledRule();
			} else {
				setSwitchLabeledRule(value);
				return false;
			}
		}
		// allow default implementation to flag the error
		return super.internalGetSetBooleanProperty(property, get, value);
	}

	@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 == EXPRESSIONS2_PROPERTY ) {
			return expressions();
		}
		// allow default implementation to flag the error
		return super.internalGetChildListProperty(property);
	}
	
	@Override
	final int getNodeType0() {
		return SWITCH_CASE;
	}

	@SuppressWarnings("unchecked")
	@Override
	ASTNode clone0(AST target) {
		SwitchCase result = new SwitchCase(target);
		result.setSourceRange(getStartPosition(), getLength());
		result.copyLeadingComment(this);
		if (this.ast.isPreviewEnabled()) {
			result.expressions().addAll(
				ASTNode.copySubtrees(target, expressions()));
		} else {
			result.setExpression(
					(Expression) ASTNode.copySubtree(target, getExpression()));
		}
		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) {
			if (this.ast.isPreviewEnabled()) {
				acceptChildren(visitor, this.expressions);
			} else {
				acceptChild(visitor, getExpression());
			}
		}
		visitor.endVisit(this);
	}

	
Returns the expression of this switch case, or
null if there is none (the "default:" case).
Returns:
the expression node, or null if there is none
Deprecated:
use expressions() (see JLS 12)/**
	 * Returns the expression of this switch case, or
	 * <code>null</code> if there is none (the "default:" case).
	 *
	 * @return the expression node, or <code>null</code> if there is none
	 * @deprecated use expressions() (see JLS 12)
	 */
	public Expression getExpression() {
		if (!this.expressionInitialized) {
			// lazy init must be thread-safe for readers
			synchronized (this) {
				if (!this.expressionInitialized) {
					preLazyInit();
					this.optionalExpression = new SimpleName(this.ast);
					this.expressionInitialized = true;
					postLazyInit(this.optionalExpression, EXPRESSION_PROPERTY);
				}
			}
		}
		return this.optionalExpression;
	}
	
	
Returns the list of expressions of this switch case, or
empty if there is none (the "default:" case). With previewEnabled flag as false it will have only one element. @return the list of expression nodes (element type: Expression) 
Throws:
UnsupportedOperationException – if this operation is used other than JLS13
UnsupportedOperationException – if this expression is used with previewEnabled flag as false
@noreference
This method is not intended to be referenced by clients as it is a part of Java preview feature.
@nooverride
This method is not intended to be re-implemented or extended by clients as it is a part of Java preview feature.
Since:
3.18/**
	 * Returns the list of expressions of this switch case, or
	 * <code>empty</code> if there is none (the "default:" case).
	 * With previewEnabled flag as false it will have only one element.
	 *
	 *  @return the list of expression nodes
	 *    (element type: {@link Expression})
	 * @exception UnsupportedOperationException if this operation is used other than JLS13
	 * @exception UnsupportedOperationException if this expression is used with previewEnabled flag as false
	 * @noreference This method is not intended to be referenced by clients as it is a part of Java preview feature.
	 * @nooverride This method is not intended to be re-implemented or extended by clients as it is a part of Java preview feature.
	 * @since 3.18
	 */
	public List expressions() {
		if (this.expressions == null) {
			supportedOnlyIn13();
			unsupportedWithoutPreviewError();
		}
		return this.expressions;
	}

	
Sets the expression of this switch case, or clears it (turns it into
the  "default:" case).
Params:
expression – the expression node, or null to
   turn it into the  "default:" case
Throws:
IllegalArgumentException – if:

the node belongs to a different AST
the node already has a parent
a cycle in would be created
Deprecated:
see JLS 12/**
	 * Sets the expression of this switch case, or clears it (turns it into
	 * the  "default:" case).
	 *
	 * @param expression the expression node, or <code>null</code> to
	 *    turn it into the  "default:" case
	 * @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>
	 * @deprecated see JLS 12
	 */
	public void setExpression(Expression expression) {
		ASTNode oldChild = this.optionalExpression;
		preReplaceChild(oldChild, expression, EXPRESSION_PROPERTY);
		this.optionalExpression = expression;
		this.expressionInitialized = true;
		postReplaceChild(oldChild, expression, EXPRESSION_PROPERTY);
	}
	
	
Sets the switchLabeledRule of this switch case as true or false.
true indicates "->" and false indicates ":".
Params:
switchLabeledRule – true or false
Throws:
UnsupportedOperationException – if this operation is used other than JLS13
UnsupportedOperationException – if this expression is used with previewEnabled flag as false
@noreference
This method is not intended to be referenced by clients as it is a part of Java preview feature.
@nooverride
This method is not intended to be re-implemented or extended by clients as it is a part of Java preview feature.
Since:
3.18/**
	 * Sets the switchLabeledRule of this switch case as <code>true</code> or <code>false</code>.
	 * <code>true</code> indicates "->" and <code>false</code> indicates ":".

	 * @param switchLabeledRule <code>true</code> or <code>false</code>
	 * @exception UnsupportedOperationException if this operation is used other than JLS13
	 * @exception UnsupportedOperationException if this expression is used with previewEnabled flag as false
	 * @noreference This method is not intended to be referenced by clients as it is a part of Java preview feature.
	 * @nooverride This method is not intended to be re-implemented or extended by clients as it is a part of Java preview feature.
	 * @since 3.18
	 */
	public void setSwitchLabeledRule(boolean switchLabeledRule) {
		supportedOnlyIn13();
		unsupportedWithoutPreviewError();
		preValueChange(SWITCH_LABELED_RULE_PROPERTY);
		this.switchLabeledRule = switchLabeledRule;
		postValueChange(SWITCH_LABELED_RULE_PROPERTY);
	}
	
	
Gets the switchLabeledRule of this switch case as true or false.
true indicates "->" and false indicates ":".
Throws:
UnsupportedOperationException – if this operation is used other than JLS13
UnsupportedOperationException – if this expression is used with previewEnabled flag as false
Returns:
switchLabeledRule true or false
@noreference
This method is not intended to be referenced by clients as it is a part of Java preview feature.
@nooverride
This method is not intended to be re-implemented or extended by clients as it is a part of Java preview feature.
Since:
3.18/**
	 * Gets the switchLabeledRule of this switch case as <code>true</code> or <code>false</code>.
	 *<code>true</code> indicates "->" and <code>false</code> indicates ":".
	 *
	 * @return switchLabeledRule <code>true</code> or <code>false</code>
	 * @exception UnsupportedOperationException if this operation is used other than JLS13
	 * @exception UnsupportedOperationException if this expression is used with previewEnabled flag as false
	 * @noreference This method is not intended to be referenced by clients as it is a part of Java preview feature.
	 * @nooverride This method is not intended to be re-implemented or extended by clients as it is a part of Java preview feature.
	 * @since 3.18
	 */
	public boolean isSwitchLabeledRule() {
		supportedOnlyIn13();
		unsupportedWithoutPreviewError();
		return this.switchLabeledRule;
	}

	
Returns whether this switch case represents the "default:" case.

This convenience method is equivalent to
getExpression() == null or expressions().isEmpty().

Returns:
true if this is the default switch case, and
   false if this is a non-default switch case/**
	 * Returns whether this switch case represents the "default:" case.
	 * <p>
	 * This convenience method is equivalent to
	 * <code>getExpression() == null</code> or <code>expressions().isEmpty()</code>.
	 * </p>
	 *
	 * @return <code>true</code> if this is the default switch case, and
	 *    <code>false</code> if this is a non-default switch case
	 */
	public boolean isDefault()  {
		if (this.ast.isPreviewEnabled()) {
			return expressions().isEmpty();
		}
		return getExpression() == null;
	}

	@Override
	int memSize() {
		return super.memSize() + 2 * 4;
	}

	@Override
	int treeSize() {
		return
			memSize()
			+ (this.optionalExpression == null ? 0 : this.optionalExpression.treeSize());
	}
	

}