Copyright (c) 2000, 2008 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, 2008 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.core.internal.expressions;

import org.w3c.dom.Element;

import org.eclipse.core.expressions.EvaluationResult;
import org.eclipse.core.expressions.Expression;
import org.eclipse.core.expressions.ExpressionInfo;
import org.eclipse.core.expressions.IEvaluationContext;

import org.eclipse.core.runtime.Assert;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IConfigurationElement;

public class InstanceofExpression extends Expression {
	
The seed for the hash code for all instance of expressions.
/**
	 * The seed for the hash code for all instance of expressions.
	 */
	private static final int HASH_INITIAL= InstanceofExpression.class.getName().hashCode();

	private String fTypeName;

	public InstanceofExpression(IConfigurationElement element) throws CoreException {
		fTypeName= element.getAttribute(ATT_VALUE);
		Expressions.checkAttribute(ATT_VALUE, fTypeName);
	}

	public InstanceofExpression(Element element) throws CoreException {
		fTypeName= element.getAttribute(ATT_VALUE);
		Expressions.checkAttribute(ATT_VALUE, fTypeName.isEmpty() ? null : fTypeName);
	}

	public InstanceofExpression(String typeName) {
		Assert.isNotNull(typeName);
		fTypeName= typeName;
	}

	/* (non-Javadoc)
	 * @see org.eclipse.jdt.internal.corext.refactoring.participants.Expression#evaluate(java.lang.Object)
	 */
	@Override
	public EvaluationResult evaluate(IEvaluationContext context) {
		Object element= context.getDefaultVariable();
		return EvaluationResult.valueOf(Expressions.isInstanceOf(element, fTypeName));
	}

	@Override
	public void collectExpressionInfo(ExpressionInfo info) {
		info.markDefaultVariableAccessed();
	}

	@Override
	public boolean equals(final Object object) {
		if (!(object instanceof InstanceofExpression))
			return false;

		final InstanceofExpression that= (InstanceofExpression) object;
		return this.fTypeName.equals(that.fTypeName);
	}

	@Override
	protected int computeHashCode() {
		return HASH_INITIAL * HASH_FACTOR + fTypeName.hashCode();
	}

	//---- Debugging ---------------------------------------------------

	@Override
	public String toString() {
		return "<instanceof value=\"" + fTypeName + "\"/>"; //$NON-NLS-1$ //$NON-NLS-2$
	}
}