/*******************************************************************************
* Copyright (c) 2000, 2006 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.core.internal.expressions;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.expressions.EvaluationResult;
import org.eclipse.core.expressions.Expression;
import org.eclipse.core.expressions.ExpressionInfo;
import org.eclipse.core.expressions.IEvaluationContext;
public abstract class CompositeExpression extends Expression {
private static final Expression[] EMPTY_ARRAY = new Expression[0];
/**
* The seed for the hash code for all composite expressions.
*/
private static final int HASH_INITIAL= CompositeExpression.class.getName().hashCode();
protected List fExpressions;
public void add(Expression expression) {
if (fExpressions == null)
fExpressions= new ArrayList(2);
fExpressions.add(expression);
}
public Expression[] getChildren() {
if (fExpressions == null)
return EMPTY_ARRAY;
return (Expression[])fExpressions.toArray(new Expression[fExpressions.size()]);
}
protected EvaluationResult evaluateAnd(IEvaluationContext scope) throws CoreException {
if (fExpressions == null)
return EvaluationResult.TRUE;
EvaluationResult result= EvaluationResult.TRUE;
for (Iterator iter= fExpressions.iterator(); iter.hasNext();) {
Expression expression= (Expression)iter.next();
result= result.and(expression.evaluate(scope));
// keep iterating even if we have a not loaded found. It can be
// that we find a false which will result in a better result.
if (result == EvaluationResult.FALSE)
return result;
}
return result;
}
protected EvaluationResult evaluateOr(IEvaluationContext scope) throws CoreException {
if (fExpressions == null)
return EvaluationResult.TRUE;
EvaluationResult result= EvaluationResult.FALSE;
for (Iterator iter= fExpressions.iterator(); iter.hasNext();) {
Expression expression= (Expression)iter.next();
result= result.or(expression.evaluate(scope));
if (result == EvaluationResult.TRUE)
return result;
}
return result;
}
public void collectExpressionInfo(ExpressionInfo info) {
if (fExpressions == null)
return;
for (Iterator iter= fExpressions.iterator(); iter.hasNext();) {
Expression expression= (Expression)iter.next();
expression.collectExpressionInfo(info);
}
}
protected int computeHashCode() {
return HASH_INITIAL * HASH_FACTOR + hashCode(fExpressions);
}
}