ITreeNodeStream`1.cs revision 324c4644fee44b9898524c09511bd33c3f12e2df 
1/*
2 * [The "BSD licence"]
3 * Copyright (c) 2005-2008 Terence Parr
4 * All rights reserved.
5 *
6 * Conversion to C#:
7 * Copyright (c) 2008-2009 Sam Harwell, Pixel Mine, Inc.
8 * All rights reserved.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 3. The name of the author may not be used to endorse or promote products
19 *    derived from this software without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
26 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 */
32
33namespace Antlr.Runtime.Tree
34{
35    public interface ITreeNodeStream<T>
36    {
37        /** <summary>
38         *  Get a tree node at an absolute index i; 0..n-1.
39         *  If you don't want to buffer up nodes, then this method makes no
40         *  sense for you.
41         *  </summary>
42         */
43        T this[int i]
44        {
45            get;
46        }
47
48        /** <summary>
49         *  Get tree node at current input pointer + i ahead where i=1 is next node.
50         *  i&lt;0 indicates nodes in the past.  So LT(-1) is previous node, but
51         *  implementations are not required to provide results for k &lt; -1.
52         *  LT(0) is undefined.  For i&gt;=n, return null.
53         *  Return null for LT(0) and any index that results in an absolute address
54         *  that is negative.
55         *  </summary>
56         *
57         *  <remarks>
58         *  This is analogus to the LT() method of the TokenStream, but this
59         *  returns a tree node instead of a token.  Makes code gen identical
60         *  for both parser and tree grammars. :)
61         *  </remarks>
62         */
63        T LT(int k);
64
65        /** <summary>
66         *  Where is this stream pulling nodes from?  This is not the name, but
67         *  the object that provides node objects.
68         *  </summary>
69         */
70        object TreeSource
71        {
72            get;
73        }
74
75        /** <summary>
76         *  If the tree associated with this stream was created from a TokenStream,
77         *  you can specify it here.  Used to do rule $text attribute in tree
78         *  parser.  Optional unless you use tree parser rule text attribute
79         *  or output=template and rewrite=true options.
80         *  </summary>
81         */
82        ITokenStream TokenStream
83        {
84            get;
85        }
86
87        /** <summary>
88         *  What adaptor can tell me how to interpret/navigate nodes and
89         *  trees.  E.g., get text of a node.
90         *  </summary>
91         */
92        ITreeAdaptor<T> TreeAdaptor
93        {
94            get;
95        }
96
97        /** <summary>
98         *  As we flatten the tree, we use UP, DOWN nodes to represent
99         *  the tree structure.  When debugging we need unique nodes
100         *  so we have to instantiate new ones.  When doing normal tree
101         *  parsing, it's slow and a waste of memory to create unique
102         *  navigation nodes.  Default should be false;
103         *  </summary>
104         */
105        bool UniqueNavigationNodes
106        {
107            get;
108            set;
109        }
110
111        /** <summary>
112         *  Return the text of all nodes from start to stop, inclusive.
113         *  If the stream does not buffer all the nodes then it can still
114         *  walk recursively from start until stop.  You can always return
115         *  null or "" too, but users should not access $ruleLabel.text in
116         *  an action of course in that case.
117         *  </summary>
118         */
119        string ToString(T start, T stop);
120
121
122        #region REWRITING TREES (used by tree parser)
123
124        /** <summary>
125         *  Replace from start to stop child index of parent with t, which might
126         *  be a list.  Number of children may be different
127         *  after this call.  The stream is notified because it is walking the
128         *  tree and might need to know you are monkeying with the underlying
129         *  tree.  Also, it might be able to modify the node stream to avoid
130         *  restreaming for future phases.
131         *  </summary>
132         *
133         *  <remarks>
134         *  If parent is null, don't do anything; must be at root of overall tree.
135         *  Can't replace whatever points to the parent externally.  Do nothing.
136         *  </remarks>
137         */
138        void ReplaceChildren(T parent, int startChildIndex, int stopChildIndex, T t);
139
140        #endregion
141    }
142}
143