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.schema;
  
  import org.apache.calcite.util.Pair;
  
  import java.util.List;
  import java.util.RandomAccess;
  
  /**
   * Path from a root schema to a particular object (schema, table, function).
   *
   * <p>Examples:
   * <ul>
   *   <li>The root schema has a single element [(root, "")].
   *   <li>A direct child "foo" of the root schema has a two elements
   *   [(root, ""), (child, "foo")].
   * </ul>
   */
  public interface Path extends List<Pair<String, Schema>>, RandomAccess {
    /** Returns the parent path, or null if the path is empty. */
    Path parent();
  
    /** Returns the names of this path, not including the name of the root. */
    List<String> names();
  
    /** Returns the schemas of this path. */
    List<Schema> schemas();
  }
  