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 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<0 indicates nodes in the past. So LT(-1) is previous node, but 51 * implementations are not required to provide results for k < -1. 52 * LT(0) is undefined. For i>=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
