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 java.util.Arrays;

import org.w3c.dom.Element;

import org.eclipse.core.expressions.EvaluationContext;
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 WithExpression extends CompositeExpression {

	private String fVariable;
	private static final String ATT_VARIABLE= "variable";  //$NON-NLS-1$

	
The seed for the hash code for all with expressions.
/**
	 * The seed for the hash code for all with expressions.
	 */
	private static final int HASH_INITIAL= WithExpression.class.getName().hashCode();

	public WithExpression(IConfigurationElement configElement) throws CoreException {
		fVariable= configElement.getAttribute(ATT_VARIABLE);
		Expressions.checkAttribute(ATT_VARIABLE, fVariable);
	}

	public WithExpression(Element element) throws CoreException {
		fVariable= element.getAttribute(ATT_VARIABLE);
		Expressions.checkAttribute(ATT_VARIABLE, fVariable.isEmpty() ? null : fVariable);
	}

	public WithExpression(String variable) {
		Assert.isNotNull(variable);
		fVariable= variable;
	}

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

		final WithExpression that= (WithExpression)object;
		return this.fVariable.equals(that.fVariable) && equals(this.fExpressions, that.fExpressions);
	}

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

	@Override
	public EvaluationResult evaluate(IEvaluationContext context) throws CoreException {
		Object variable= context.getVariable(fVariable);
		if (variable == null) {
			throw new CoreException(new ExpressionStatus(
				ExpressionStatus.VARIABLE_NOT_DEFINED,
				Messages.format(ExpressionMessages.WithExpression_variable_not_defined, fVariable)));
		}
		if (variable == IEvaluationContext.UNDEFINED_VARIABLE) {
			return EvaluationResult.FALSE;
		}
		return evaluateAnd(new EvaluationContext(context, variable));
	}

	@Override
	public void collectExpressionInfo(ExpressionInfo info) {
		ExpressionInfo other= new ExpressionInfo();
		super.collectExpressionInfo(other);
		if (other.hasDefaultVariableAccess()) {
			info.addVariableNameAccess(fVariable);
		}
		info.mergeExceptDefaultVariable(other);
	}

	@Override
	public String toString() {
		StringBuilder builder = new StringBuilder(getClass().getSimpleName());
		builder.append(" [variable=").append(fVariable); //$NON-NLS-1$
		Expression[] children = getChildren();
		if (children.length > 0) {
			builder.append(", children="); //$NON-NLS-1$
			builder.append(Arrays.toString(children));
		}
		builder.append("]"); //$NON-NLS-1$
		return builder.toString();
	}
}