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.linq4j;
  
  import org.checkerframework.framework.qual.Covariant;
  
  /**
   * Exposes the enumerator, which supports a simple iteration over a collection,
   * without the extension methods.
   *
   * <p>Just the bare methods, to make it easier to implement. Code that requires
   * the extension methods can use the static methods in {@link Extensions}.
   *
   * <p>Analogous to LINQ's System.Collections.IEnumerable (both generic
   * and non-generic variants), without the extension methods.
   *
   * @param <T> Element type
   * @see Enumerable
   */
  @Covariant(0)
  public interface RawEnumerable<T> {
    /**
     * Returns an enumerator that iterates through a collection.
     */
    Enumerator<T> enumerator();
  }
  