ChildReplacer.java

/*
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.facebook.presto.sql.planner.plan;

import com.facebook.presto.spi.plan.PlanNode;

import java.util.List;

public class ChildReplacer
{
    private ChildReplacer()
    {
    }

    /**
     * Return an identical copy of the given node with its children replaced
     */
    public static PlanNode replaceChildren(PlanNode node, List<PlanNode> children)
    {
        for (int i = 0; i < node.getSources().size(); i++) {
            if (children.get(i) != node.getSources().get(i)) {
                return node.replaceChildren(children);
            }
        }
        return node;
    }
}