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