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.util.format;
  
  import java.util.List;
  import java.util.Map;
  
  /**
   * Describes the format strings used by a formatting function such as
   * {@code FORMAT_TIMESTAMP} or {@code CAST(string AS DATE FORMAT formatString)}.
   *
   * <p>Can parse a format string to a list of format elements.
   *
   * @see FormatModels
   */
  public interface FormatModel {
    /** Returns the map used to create the {@link FormatModel} instance. */
    Map<String, FormatElement> getElementMap();
  
    /** Parses a format string using element identifiers supplied by
     * {@code format}. */
    List<FormatElement> parse(String format);
  
    /** As {@link #parse}, but does not cache. */
    List<FormatElement> parseNoCache(String format);
  }
  