/interpreter/tags/at2dist130208/src/edu/vub/at/objects/natives/grammar/NATAbstractGrammar.java

 1/**
 2 * AmbientTalk/2 Project
 3 * NATAbstractGrammar.java created on 26-jul-2006 at 11:57:00
 4 * (c) Programming Technology Lab, 2006 - 2007
 5 * Authors: Tom Van Cutsem & Stijn Mostinckx
 6 * 
 7 * Permission is hereby granted, free of charge, to any person
 8 * obtaining a copy of this software and associated documentation
 9 * files (the "Software"), to deal in the Software without
10 * restriction, including without limitation the rights to use,
11 * copy, modify, merge, publish, distribute, sublicense, and/or
12 * sell copies of the Software, and to permit persons to whom the
13 * Software is furnished to do so, subject to the following
14 * conditions:
15 *
16 * The above copyright notice and this permission notice shall be
17 * included in all copies or substantial portions of the Software.
18 *
19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
20 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
21 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
22 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
23 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
24 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
25 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
26 * OTHER DEALINGS IN THE SOFTWARE.
27 */
28package edu.vub.at.objects.natives.grammar;
29
30import edu.vub.at.exceptions.InterpreterException;
31import edu.vub.at.objects.ATAbstractGrammar;
32import edu.vub.at.objects.ATTable;
33import edu.vub.at.objects.coercion.NativeTypeTags;
34import edu.vub.at.objects.natives.NATByCopy;
35import edu.vub.at.objects.natives.NATTable;
36
37/**
38 * @author tvc
39 *
40 * NATAbstractGrammar is the common superclass of all native ambienttalk objects
41 * that represent abstract grammar parse tree elements. That is, any object that
42 * can be returned as part of the AST produced by the native parser.
43 */
44public abstract class NATAbstractGrammar extends NATByCopy implements ATAbstractGrammar {
45
46	// This is an empty superclass used only for proper documentation and
47	// to identify which native objects can be output by the parser.
48	
49	// subclasses of NATAbstractGrammar will override meta_eval and meta_quote as appropriate,
50	// except for the literal grammar elements which can inherit the self-evaluating behaviour of NATNil.
51	
52    public ATTable meta_typeTags() throws InterpreterException {
53    	return NATTable.of(NativeTypeTags._ABSTRACTGRAMMAR_, NativeTypeTags._ISOLATE_);
54    }
55	
56}