/*
* Copyright (c) 2015 Cisco Systems, Inc. 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
*/
package org.opendaylight.yangtools.yang.data.api.schema.xpath;
import com.google.common.annotations.Beta;
import javax.annotation.Nonnull;
/**
* Interface implemented by {@link XPathExpression}s which can be further optimized for execution efficiency at the
* expense of additional processing being performed on them. The decision to optimize a particular expression is left
* to the user's discretion.
*
* Implementations supporting profile-driven and similar optimizations which depend on data being gathered during
* evaluation should not implement this interface, but rather perform these optimizations transparently behind the
* scenes. That implies the users can expect those optimizations not interfering with the user's ability to evaluate
* the expression.
*/
@Beta
public interface OptimizableXPathExpression extends XPathExpression {
/**
* Perform optimization of this expression. If an implementation supports different levels of optimization, it
* should return an {@link OptimizableXPathExpression} as a result of progressing optimizations for as long as
* it determines further processing can result in execution benefits. Note this expression is expected to remain
* unchanged.
*
* @return An optimized version of this expression.
*/
@Nonnull XPathExpression optimizeExpression();
}