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 34 { 35 using System.Collections.Generic; 36 using CLSCompliant = System.CLSCompliantAttribute; 37 using ArgumentNullException = System.ArgumentNullException; 38 39 /** <summary> 40 * The set of fields needed by an abstract recognizer to recognize input 41 * and recover from errors etc... As a separate state object, it can be 42 * shared among multiple grammars; e.g., when one grammar imports another. 43 * </summary> 44 * 45 * <remarks> 46 * These fields are publically visible but the actual state pointer per 47 * parser is protected. 48 * </remarks> 49 */ 50 public class RecognizerSharedState 51 { 52 /** <summary> 53 * Track the set of token types that can follow any rule invocation. 54 * Stack grows upwards. When it hits the max, it grows 2x in size 55 * and keeps going. 56 * </summary> 57 */ 58 //public List<BitSet> following; 59 public BitSet[] following; 60 [CLSCompliant( false )] 61 public int _fsp; 62 63 /** <summary> 64 * This is true when we see an error and before having successfully 65 * matched a token. Prevents generation of more than one error message 66 * per error. 67 * </summary> 68 */ 69 public bool errorRecovery; 70 71 /** <summary> 72 * The index into the input stream where the last error occurred. 73 * This is used to prevent infinite loops where an error is found 74 * but no token is consumed during recovery...another error is found, 75 * ad naseum. This is a failsafe mechanism to guarantee that at least 76 * one token/tree node is consumed for two errors. 77 * </summary> 78 */ 79 public int lastErrorIndex; 80 81 /** <summary> 82 * In lieu of a return value, this indicates that a rule or token 83 * has failed to match. Reset to false upon valid token match. 84 * </summary> 85 */ 86 public bool failed; 87 88 /** <summary>Did the recognizer encounter a syntax error? Track how many.</summary> */ 89 public int syntaxErrors; 90 91 /** <summary> 92 * If 0, no backtracking is going on. Safe to exec actions etc... 93 * If >0 then it's the level of backtracking. 94 * </summary> 95 */ 96 public int backtracking; 97 98 /** <summary> 99 * An array[size num rules] of Map<Integer,Integer> that tracks 100 * the stop token index for each rule. ruleMemo[ruleIndex] is 101 * the memoization table for ruleIndex. For key ruleStartIndex, you 102 * get back the stop token for associated rule or MEMO_RULE_FAILED. 103 * </summary> 104 * 105 * <remarks>This is only used if rule memoization is on (which it is by default).</remarks> 106 */ 107 public IDictionary<int, int>[] ruleMemo; 108 109 110 // LEXER FIELDS (must be in same state object to avoid casting 111 // constantly in generated code and Lexer object) :( 112 113 114 /** <summary> 115 * The goal of all lexer rules/methods is to create a token object. 116 * This is an instance variable as multiple rules may collaborate to 117 * create a single token. nextToken will return this object after 118 * matching lexer rule(s). If you subclass to allow multiple token 119 * emissions, then set this to the last token to be matched or 120 * something nonnull so that the auto token emit mechanism will not 121 * emit another token. 122 * </summary> 123 */ 124 public IToken token; 125 126 /** <summary> 127 * What character index in the stream did the current token start at? 128 * Needed, for example, to get the text for current token. Set at 129 * the start of nextToken. 130 * </summary> 131 */ 132 public int tokenStartCharIndex; 133 134 /** <summary>The line on which the first character of the token resides</summary> */ 135 public int tokenStartLine; 136 137 /** <summary>The character position of first character within the line</summary> */ 138 public int tokenStartCharPositionInLine; 139 140 /** <summary>The channel number for the current token</summary> */ 141 public int channel; 142 143 /** <summary>The token type for the current token</summary> */ 144 public int type; 145 146 /** <summary> 147 * You can set the text for the current token to override what is in 148 * the input char buffer. Use setText() or can set this instance var. 149 * </summary> 150 */ 151 public string text; 152 RecognizerSharedState()153 public RecognizerSharedState() 154 { 155 //following = new List<BitSet>( BaseRecognizer.InitialFollowStackSize ); 156 following = new BitSet[BaseRecognizer.InitialFollowStackSize]; 157 _fsp = -1; 158 lastErrorIndex = -1; 159 tokenStartCharIndex = -1; 160 } 161 RecognizerSharedState( RecognizerSharedState state )162 public RecognizerSharedState( RecognizerSharedState state ) 163 { 164 if (state == null) 165 throw new ArgumentNullException("state"); 166 167 following = (BitSet[])state.following.Clone(); 168 _fsp = state._fsp; 169 errorRecovery = state.errorRecovery; 170 lastErrorIndex = state.lastErrorIndex; 171 failed = state.failed; 172 syntaxErrors = state.syntaxErrors; 173 backtracking = state.backtracking; 174 175 if ( state.ruleMemo != null ) 176 ruleMemo = (IDictionary<int, int>[])state.ruleMemo.Clone(); 177 178 token = state.token; 179 tokenStartCharIndex = state.tokenStartCharIndex; 180 tokenStartCharPositionInLine = state.tokenStartCharPositionInLine; 181 channel = state.channel; 182 type = state.type; 183 text = state.text; 184 } 185 } 186 } 187