content: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to you 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 org.apache.calcite.sql.validate;
  
  import org.apache.calcite.rel.type.RelDataType;
  import org.apache.calcite.sql.SqlLambda;
  import org.apache.calcite.sql.SqlNode;
  
  import org.checkerframework.checker.nullness.qual.Nullable;
  
  import static java.util.Objects.requireNonNull;
  
  /**
   * Namespace for {@code lambda expression}.
   */
  public class LambdaNamespace extends AbstractNamespace {
    private final SqlLambda lambdaExpression;
  
    /**
     * Creates a LambdaNamespace.
     */
    LambdaNamespace(SqlValidatorImpl validator, SqlLambda lambdaExpression,
        SqlNode enclosingNode) {
      super(validator, enclosingNode);
      this.lambdaExpression = lambdaExpression;
    }
  
    @Override protected RelDataType validateImpl(RelDataType targetRowType) {
      validator.validateLambda(lambdaExpression);
      requireNonNull(rowType, "rowType");
      return rowType;
    }
  
    @Override public @Nullable SqlNode getNode() {
      return lambdaExpression;
    }
  }
  