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 28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 namespace Antlr.Runtime.Tree { 34 /** <summary>A stream of tree nodes, accessing nodes from a tree of some kind</summary> */ 35 public interface ITreeNodeStream : IIntStream { 36 /** <summary> 37 * Get a tree node at an absolute index i; 0..n-1. 38 * If you don't want to buffer up nodes, then this method makes no 39 * sense for you. 40 * </summary> 41 */ 42 object this[int i] { 43 get; 44 } 45 46 /** <summary> 47 * Get tree node at current input pointer + i ahead where i=1 is next node. 48 * i<0 indicates nodes in the past. So LT(-1) is previous node, but 49 * implementations are not required to provide results for k < -1. 50 * LT(0) is undefined. For i>=n, return null. 51 * Return null for LT(0) and any index that results in an absolute address 52 * that is negative. 53 * </summary> 54 * 55 * <remarks> 56 * This is analogus to the LT() method of the TokenStream, but this 57 * returns a tree node instead of a token. Makes code gen identical 58 * for both parser and tree grammars. :) 59 * </remarks> 60 */ 61 object LT(int k); 62 63 /** <summary> 64 * Where is this stream pulling nodes from? This is not the name, but 65 * the object that provides node objects. 66 * </summary> 67 */ 68 object TreeSource { 69 get; 70 } 71 72 /** <summary> 73 * If the tree associated with this stream was created from a TokenStream, 74 * you can specify it here. Used to do rule $text attribute in tree 75 * parser. Optional unless you use tree parser rule text attribute 76 * or output=template and rewrite=true options. 77 * </summary> 78 */ 79 ITokenStream TokenStream { 80 get; 81 } 82 83 /** <summary> 84 * What adaptor can tell me how to interpret/navigate nodes and 85 * trees. E.g., get text of a node. 86 * </summary> 87 */ 88 ITreeAdaptor TreeAdaptor { 89 get; 90 } 91 92 /** <summary> 93 * As we flatten the tree, we use UP, DOWN nodes to represent 94 * the tree structure. When debugging we need unique nodes 95 * so we have to instantiate new ones. When doing normal tree 96 * parsing, it's slow and a waste of memory to create unique 97 * navigation nodes. Default should be false; 98 * </summary> 99 */ 100 bool UniqueNavigationNodes { 101 get; 102 set; 103 } 104 105 /** <summary> 106 * Return the text of all nodes from start to stop, inclusive. 107 * If the stream does not buffer all the nodes then it can still 108 * walk recursively from start until stop. You can always return 109 * null or "" too, but users should not access $ruleLabel.text in 110 * an action of course in that case. 111 * </summary> 112 */ 113 string ToString(object start, object stop); 114 115 116 #region REWRITING TREES (used by tree parser) 117 118 /** <summary> 119 * Replace from start to stop child index of parent with t, which might 120 * be a list. Number of children may be different 121 * after this call. The stream is notified because it is walking the 122 * tree and might need to know you are monkeying with the underlying 123 * tree. Also, it might be able to modify the node stream to avoid 124 * restreaming for future phases. 125 * </summary> 126 * 127 * <remarks> 128 * If parent is null, don't do anything; must be at root of overall tree. 129 * Can't replace whatever points to the parent externally. Do nothing. 130 * </remarks> 131 */ 132 void ReplaceChildren(object parent, int startChildIndex, int stopChildIndex, object t); 133 134 #endregion 135 136 } 137 } 138
