View Javadoc

1   /**
2    * Copyright (c) 2008-2011, http://www.snakeyaml.org
3    *
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    *
8    *     http://www.apache.org/licenses/LICENSE-2.0
9    *
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  
17  package org.yaml.snakeyaml.parser;
18  
19  import org.yaml.snakeyaml.events.Event;
20  
21  /**
22   * This interface represents an input stream of {@link Event Events}.
23   * <p>
24   * The parser and the scanner form together the 'Parse' step in the loading
25   * process (see chapter 3.1 of the <a href="http://yaml.org/spec/1.1/">YAML
26   * Specification</a>).
27   * </p>
28   * 
29   * @see org.yaml.snakeyaml.events.Event
30   */
31  public interface Parser {
32  
33      /**
34       * Check if the next event is one of the given type.
35       * 
36       * @param choice
37       *            Event ID.
38       * @return <code>true</code> if the next event can be assigned to a variable
39       *         of the given type. Returns <code>false</code> if no more events
40       *         are available.
41       * @throws ParserException
42       *             Thrown in case of malformed input.
43       */
44      public boolean checkEvent(Event.ID choice);
45  
46      /**
47       * Return the next event, but do not delete it from the stream.
48       * 
49       * @return The event that will be returned on the next call to
50       *         {@link #getEvent}
51       * @throws ParserException
52       *             Thrown in case of malformed input.
53       */
54      public Event peekEvent();
55  
56      /**
57       * Returns the next event.
58       * <p>
59       * The event will be removed from the stream.
60       * </p>
61       * 
62       * @throws ParserException
63       *             Thrown in case of malformed input.
64       */
65      public Event getEvent();
66  }