Copyright (c) 2000, 2013 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, 2013 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.HashMap;
import java.util.List;
import java.util.Map;

Assignment expression AST node type.
Assignment:
   Expression AssignmentOperator Expression

Since:
2.0
@noinstantiate
This class is not intended to be instantiated by clients./**
 * Assignment expression AST node type.
 *
 * <pre>
 * Assignment:
 *    Expression AssignmentOperator Expression
 * </pre>
 *
 * @since 2.0
 * @noinstantiate This class is not intended to be instantiated by clients.
 */
@SuppressWarnings({"rawtypes", "unchecked"})
public class Assignment extends Expression {

	
Assignment operators (typesafe enumeration).
AssignmentOperator:
   = ASSIGN
   += PLUS_ASSIGN
   -= MINUS_ASSIGN
   *= TIMES_ASSIGN
   /= DIVIDE_ASSIGN
   &= BIT_AND_ASSIGN
   |= BIT_OR_ASSIGN
   ^= BIT_XOR_ASSIGN
   %= REMAINDER_ASSIGN
   <<= LEFT_SHIFT_ASSIGN
   >>= RIGHT_SHIFT_SIGNED_ASSIGN
   >>>= RIGHT_SHIFT_UNSIGNED_ASSIGN

/**
 	 * Assignment operators (typesafe enumeration).
	 * <pre>
	 * AssignmentOperator:<code>
	 *    <b>=</b> ASSIGN
	 *    <b>+=</b> PLUS_ASSIGN
	 *    <b>-=</b> MINUS_ASSIGN
	 *    <b>*=</b> TIMES_ASSIGN
	 *    <b>/=</b> DIVIDE_ASSIGN
	 *    <b>&amp;=</b> BIT_AND_ASSIGN
	 *    <b>|=</b> BIT_OR_ASSIGN
	 *    <b>^=</b> BIT_XOR_ASSIGN
	 *    <b>%=</b> REMAINDER_ASSIGN
	 *    <b>&lt;&lt;=</b> LEFT_SHIFT_ASSIGN
	 *    <b>&gt;&gt;=</b> RIGHT_SHIFT_SIGNED_ASSIGN
	 *    <b>&gt;&gt;&gt;=</b> RIGHT_SHIFT_UNSIGNED_ASSIGN</code>
	 * </pre>
	 */
	public static class Operator {

		
The name of the operator
/**
		 * The name of the operator
		 */
		private String op;

		
Creates a new assignment operator with the given name.

Note: this constructor is private. The only instances
ever created are the ones for the standard operators.

Params:
op – the character sequence for the operator/**
		 * Creates a new assignment operator with the given name.
		 * <p>
		 * Note: this constructor is private. The only instances
		 * ever created are the ones for the standard operators.
		 * </p>
		 *
		 * @param op the character sequence for the operator
		 */
		private Operator(String op) {
			this.op = op;
		}

		
Returns the character sequence for the operator.
Returns:
the character sequence for the operator/**
		 * Returns the character sequence for the operator.
		 *
		 * @return the character sequence for the operator
		 */
		@Override
		public String toString() {
			return this.op;
		}

		
= operator. /** = operator. */
		public static final Operator ASSIGN = new Operator("=");//$NON-NLS-1$
		
+= operator. /** += operator. */
		public static final Operator PLUS_ASSIGN = new Operator("+=");//$NON-NLS-1$
		
-= operator. /** -= operator. */
		public static final Operator MINUS_ASSIGN = new Operator("-=");//$NON-NLS-1$
		
 *= operator. /** *= operator. */
		public static final Operator TIMES_ASSIGN = new Operator("*=");//$NON-NLS-1$
		
/= operator. /** /= operator. */
		public static final Operator DIVIDE_ASSIGN = new Operator("/=");//$NON-NLS-1$
		
&= operator. /** &amp;= operator. */
		public static final Operator BIT_AND_ASSIGN = new Operator("&=");//$NON-NLS-1$
		
|= operator. /** |= operator. */
		public static final Operator BIT_OR_ASSIGN = new Operator("|=");//$NON-NLS-1$
		
^= operator. /** ^= operator. */
		public static final Operator BIT_XOR_ASSIGN = new Operator("^=");//$NON-NLS-1$
		
%= operator. /** %= operator. */
		public static final Operator REMAINDER_ASSIGN = new Operator("%=");//$NON-NLS-1$
		
<<== operator. /** &lt;&lt;== operator. */
		public static final Operator LEFT_SHIFT_ASSIGN =
			new Operator("<<=");//$NON-NLS-1$
		
>>= operator. /** &gt;&gt;= operator. */
		public static final Operator RIGHT_SHIFT_SIGNED_ASSIGN =
			new Operator(">>=");//$NON-NLS-1$
		
>>>= operator. /** &gt;&gt;&gt;= operator. */
		public static final Operator RIGHT_SHIFT_UNSIGNED_ASSIGN =
			new Operator(">>>=");//$NON-NLS-1$

		
Returns the assignment operator corresponding to the given string,
or null if none.

toOperator is the converse of toString:
that is, Operator.toOperator(op.toString()) == op for all
operators op.

Params:
token – the character sequence for the operator
Returns:
the assignment operator, or null if none/**
		 * Returns the assignment operator corresponding to the given string,
		 * or <code>null</code> if none.
		 * <p>
		 * <code>toOperator</code> is the converse of <code>toString</code>:
		 * that is, <code>Operator.toOperator(op.toString()) == op</code> for all
		 * operators <code>op</code>.
		 * </p>
		 *
		 * @param token the character sequence for the operator
		 * @return the assignment operator, or <code>null</code> if none
		 */
		public static Operator toOperator(String token) {
			return (Operator) CODES.get(token);
		}

		
Map from token to operator (key type: String;
value type: Operator).
/**
		 * Map from token to operator (key type: <code>String</code>;
		 * value type: <code>Operator</code>).
		 */
		private static final Map CODES;
		static {
			CODES = new HashMap(20);
			Operator[] ops = {
					ASSIGN,
					PLUS_ASSIGN,
					MINUS_ASSIGN,
					TIMES_ASSIGN,
					DIVIDE_ASSIGN,
					BIT_AND_ASSIGN,
					BIT_OR_ASSIGN,
					BIT_XOR_ASSIGN,
					REMAINDER_ASSIGN,
					LEFT_SHIFT_ASSIGN,
					RIGHT_SHIFT_SIGNED_ASSIGN,
					RIGHT_SHIFT_UNSIGNED_ASSIGN
				};
			for (int i = 0; i < ops.length; i++) {
				CODES.put(ops[i].toString(), ops[i]);
			}
		}
	}

	
The "leftHandSide" structural property of this node type (child type: Expression). 
Since:
3.0/**
	 * The "leftHandSide" structural property of this node type (child type: {@link Expression}).
	 * @since 3.0
	 */
	public static final ChildPropertyDescriptor LEFT_HAND_SIDE_PROPERTY =
		new ChildPropertyDescriptor(Assignment.class, "leftHandSide", Expression.class, MANDATORY, CYCLE_RISK); //$NON-NLS-1$

	
The "operator" structural property of this node type (type: Operator). 
Since:
3.0/**
	 * The "operator" structural property of this node type (type: {@link Assignment.Operator}).
	 * @since 3.0
	 */
	public static final SimplePropertyDescriptor OPERATOR_PROPERTY =
		new SimplePropertyDescriptor(Assignment.class, "operator", Assignment.Operator.class, MANDATORY); //$NON-NLS-1$

	
The "rightHandSide" structural property of this node type (child type: Expression). 
Since:
3.0/**
	 * The "rightHandSide" structural property of this node type (child type: {@link Expression}).
	 * @since 3.0
	 */
	public static final ChildPropertyDescriptor RIGHT_HAND_SIDE_PROPERTY =
		new ChildPropertyDescriptor(Assignment.class, "rightHandSide", Expression.class, MANDATORY, 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 properyList = new ArrayList(4);
		createPropertyList(Assignment.class, properyList);
		addProperty(LEFT_HAND_SIDE_PROPERTY, properyList);
		addProperty(OPERATOR_PROPERTY, properyList);
		addProperty(RIGHT_HAND_SIDE_PROPERTY, properyList);
		PROPERTY_DESCRIPTORS = reapPropertyList(properyList);
	}

	
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 PROPERTY_DESCRIPTORS;
	}

	
The assignment operator; defaults to Assignment.Operator.ASSIGN
/**
	 * The assignment operator; defaults to Assignment.Operator.ASSIGN
	 */
	private Assignment.Operator assignmentOperator = Assignment.Operator.ASSIGN;

	
The left hand side; lazily initialized; defaults to an unspecified,
but legal, simple name.
/**
	 * The left hand side; lazily initialized; defaults to an unspecified,
	 * but legal, simple name.
	 */
	private Expression leftHandSide = null;

	
The right hand side; lazily initialized; defaults to an unspecified,
but legal, simple name.
/**
	 * The right hand side; lazily initialized; defaults to an unspecified,
	 * but legal, simple name.
	 */
	private Expression rightHandSide = null;

	
Creates a new AST node for an assignment expression owned by the given
AST. By default, the node has an assignment operator, and unspecified
left and right hand sides.
Params:
ast – the AST that is to own this node/**
	 * Creates a new AST node for an assignment expression owned by the given
	 * AST. By default, the node has an assignment operator, and unspecified
	 * left and right hand sides.
	 *
	 * @param ast the AST that is to own this node
	 */
	Assignment(AST ast) {
		super(ast);
	}

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

	@Override
	final Object internalGetSetObjectProperty(SimplePropertyDescriptor property, boolean get, Object value) {
		if (property == OPERATOR_PROPERTY) {
			if (get) {
				return getOperator();
			} else {
				setOperator((Operator) value);
				return null;
			}
		}
		// allow default implementation to flag the error
		return super.internalGetSetObjectProperty(property, get, value);
	}

	@Override
	final ASTNode internalGetSetChildProperty(ChildPropertyDescriptor property, boolean get, ASTNode child) {
		if (property == LEFT_HAND_SIDE_PROPERTY) {
			if (get) {
				return getLeftHandSide();
			} else {
				setLeftHandSide((Expression) child);
				return null;
			}
		}
		if (property == RIGHT_HAND_SIDE_PROPERTY) {
			if (get) {
				return getRightHandSide();
			} else {
				setRightHandSide((Expression) child);
				return null;
			}
		}
		// allow default implementation to flag the error
		return super.internalGetSetChildProperty(property, get, child);
	}

	@Override
	final int getNodeType0() {
		return ASSIGNMENT;
	}

	@Override
	ASTNode clone0(AST target) {
		Assignment result = new Assignment(target);
		result.setSourceRange(getStartPosition(), getLength());
		result.setOperator(getOperator());
		result.setLeftHandSide((Expression) getLeftHandSide().clone(target));
		result.setRightHandSide((Expression) getRightHandSide().clone(target));
		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, getLeftHandSide());
			acceptChild(visitor, getRightHandSide());
		}
		visitor.endVisit(this);
	}

	
Returns the operator of this assignment expression.
Returns:
the assignment operator/**
	 * Returns the operator of this assignment expression.
	 *
	 * @return the assignment operator
	 */
	public Assignment.Operator getOperator() {
		return this.assignmentOperator;
	}

	
Sets the operator of this assignment expression.
Params:
assignmentOperator – the assignment operator
Throws:
IllegalArgumentException – if the argument is incorrect/**
	 * Sets the operator of this assignment expression.
	 *
	 * @param assignmentOperator the assignment operator
	 * @exception IllegalArgumentException if the argument is incorrect
	 */
	public void setOperator(Assignment.Operator assignmentOperator) {
		if (assignmentOperator == null) {
			throw new IllegalArgumentException();
		}
		preValueChange(OPERATOR_PROPERTY);
		this.assignmentOperator = assignmentOperator;
		postValueChange(OPERATOR_PROPERTY);
	}

	
Returns the left hand side of this assignment expression.
Returns:
the left hand side node/**
	 * Returns the left hand side of this assignment expression.
	 *
	 * @return the left hand side node
	 */
	public Expression getLeftHandSide() {
		if (this.leftHandSide  == null) {
			// lazy init must be thread-safe for readers
			synchronized (this) {
				if (this.leftHandSide == null) {
					preLazyInit();
					this.leftHandSide= new SimpleName(this.ast);
					postLazyInit(this.leftHandSide, LEFT_HAND_SIDE_PROPERTY);
				}
			}
		}
		return this.leftHandSide;
	}

	
Sets the left hand side of this assignment expression.
Params:
expression – the left hand side 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 left hand side of this assignment expression.
	 *
	 * @param expression the left hand side 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 setLeftHandSide(Expression expression) {
		if (expression == null) {
			throw new IllegalArgumentException();
		}
		// an Assignment may occur inside a Expression - must check cycles
		ASTNode oldChild = this.leftHandSide;
		preReplaceChild(oldChild, expression, LEFT_HAND_SIDE_PROPERTY);
		this.leftHandSide = expression;
		postReplaceChild(oldChild, expression, LEFT_HAND_SIDE_PROPERTY);
	}

	
Returns the right hand side of this assignment expression.
Returns:
the right hand side node/**
	 * Returns the right hand side of this assignment expression.
	 *
	 * @return the right hand side node
	 */
	public Expression getRightHandSide() {
		if (this.rightHandSide  == null) {
			// lazy init must be thread-safe for readers
			synchronized (this) {
				if (this.rightHandSide == null) {
					preLazyInit();
					this.rightHandSide= new SimpleName(this.ast);
					postLazyInit(this.rightHandSide, RIGHT_HAND_SIDE_PROPERTY);
				}
			}
		}
		return this.rightHandSide;
	}

	
Sets the right hand side of this assignment expression.
Params:
expression – the right hand side 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 right hand side of this assignment expression.
	 *
	 * @param expression the right hand side 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 setRightHandSide(Expression expression) {
		if (expression == null) {
			throw new IllegalArgumentException();
		}
		// an Assignment may occur inside a Expression - must check cycles
		ASTNode oldChild = this.rightHandSide;
		preReplaceChild(oldChild, expression, RIGHT_HAND_SIDE_PROPERTY);
		this.rightHandSide = expression;
		postReplaceChild(oldChild, expression, RIGHT_HAND_SIDE_PROPERTY);
	}

	@Override
	int memSize() {
		// treat Code as free
		return BASE_NODE_SIZE + 3 * 4;
	}

	@Override
	int treeSize() {
		return
			memSize()
			+ (this.leftHandSide == null ? 0 : getLeftHandSide().treeSize())
			+ (this.rightHandSide == null ? 0 : getRightHandSide().treeSize());
	}
}