RowExpressionNodeInliner.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.expressions;

import com.facebook.presto.spi.relation.RowExpression;

import java.util.Map;

public class RowExpressionNodeInliner
        extends RowExpressionRewriter<Void>
{
    private final Map<? extends RowExpression, ? extends RowExpression> mappings;

    public static RowExpression replaceExpression(RowExpression expression, Map<? extends RowExpression, ? extends RowExpression> mappings)
    {
        return RowExpressionTreeRewriter.rewriteWith(new RowExpressionNodeInliner(mappings), expression);
    }

    public RowExpressionNodeInliner(Map<? extends RowExpression, ? extends RowExpression> mappings)
    {
        this.mappings = mappings;
    }

    @Override
    public RowExpression rewriteRowExpression(RowExpression node, Void context, RowExpressionTreeRewriter<Void> treeRewriter)
    {
        return mappings.get(node);
    }
}