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 { 35 /** <summary>A stream of tree nodes, accessing nodes from a tree of some kind</summary> */ 36 public interface ITreeNodeStream : IIntStream 37 { 38 /** <summary> 39 * Get a tree node at an absolute index i; 0..n-1. 40 * If you don't want to buffer up nodes, then this method makes no 41 * sense for you. 42 * </summary> 43 */ 44 object this[int i] 45 { 46 get; 47 } 48 49 /** <summary> 50 * Get tree node at current input pointer + i ahead where i=1 is next node. 51 * i<0 indicates nodes in the past. So LT(-1) is previous node, but 52 * implementations are not required to provide results for k < -1. 53 * LT(0) is undefined. For i>=n, return null. 54 * Return null for LT(0) and any index that results in an absolute address 55 * that is negative. 56 * </summary> 57 * 58 * <remarks> 59 * This is analogus to the LT() method of the TokenStream, but this 60 * returns a tree node instead of a token. Makes code gen identical 61 * for both parser and tree grammars. :) 62 * </remarks> 63 */ 64 object LT( int k ); 65 66 /** <summary> 67 * Where is this stream pulling nodes from? This is not the name, but 68 * the object that provides node objects. 69 * </summary> 70 */ 71 object TreeSource 72 { 73 get; 74 } 75 76 /** <summary> 77 * If the tree associated with this stream was created from a TokenStream, 78 * you can specify it here. Used to do rule $text attribute in tree 79 * parser. Optional unless you use tree parser rule text attribute 80 * or output=template and rewrite=true options. 81 * </summary> 82 */ 83 ITokenStream TokenStream 84 { 85 get; 86 } 87 88 /** <summary> 89 * What adaptor can tell me how to interpret/navigate nodes and 90 * trees. E.g., get text of a node. 91 * </summary> 92 */ 93 ITreeAdaptor TreeAdaptor 94 { 95 get; 96 } 97 98 /** <summary> 99 * As we flatten the tree, we use UP, DOWN nodes to represent 100 * the tree structure. When debugging we need unique nodes 101 * so we have to instantiate new ones. When doing normal tree 102 * parsing, it's slow and a waste of memory to create unique 103 * navigation nodes. Default should be false; 104 * </summary> 105 */ 106 bool UniqueNavigationNodes 107 { 108 get; 109 set; 110 } 111 112 /** <summary> 113 * Return the text of all nodes from start to stop, inclusive. 114 * If the stream does not buffer all the nodes then it can still 115 * walk recursively from start until stop. You can always return 116 * null or "" too, but users should not access $ruleLabel.text in 117 * an action of course in that case. 118 * </summary> 119 */ 120 string ToString( object start, object stop ); 121 122 123 #region REWRITING TREES (used by tree parser) 124 125 /** <summary> 126 * Replace from start to stop child index of parent with t, which might 127 * be a list. Number of children may be different 128 * after this call. The stream is notified because it is walking the 129 * tree and might need to know you are monkeying with the underlying 130 * tree. Also, it might be able to modify the node stream to avoid 131 * restreaming for future phases. 132 * </summary> 133 * 134 * <remarks> 135 * If parent is null, don't do anything; must be at root of overall tree. 136 * Can't replace whatever points to the parent externally. Do nothing. 137 * </remarks> 138 */ 139 void ReplaceChildren( object parent, int startChildIndex, int stopChildIndex, object t ); 140 141 #endregion 142 143 } 144 } 145
