1 /** The set of fields needed by an abstract recognizer to recognize input 2 * and recover from errors etc... As a separate state object, it can be 3 * shared among multiple grammars; e.g., when one grammar imports another. 4 * 5 * These fields are publically visible but the actual state pointer per 6 * parser is protected. 7 */ 8 org.antlr.runtime.RecognizerSharedState = function() { 9 /** Track the set of token types that can follow any rule invocation. 10 * Stack grows upwards. When it hits the max, it grows 2x in size 11 * and keeps going. 12 */ 13 this.following = []; 14 15 this._fsp = -1; 16 17 /** This is true when we see an error and before having successfully 18 * matched a token. Prevents generation of more than one error message 19 * per error. 20 */ 21 this.errorRecovery = false; 22 23 /** The index into the input stream where the last error occurred. 24 * This is used to prevent infinite loops where an error is found 25 * but no token is consumed during recovery...another error is found, 26 * ad naseum. This is a failsafe mechanism to guarantee that at least 27 * one token/tree node is consumed for two errors. 28 */ 29 this.lastErrorIndex = -1; 30 31 /** In lieu of a return value, this indicates that a rule or token 32 * has failed to match. Reset to false upon valid token match. 33 */ 34 this.failed = false; 35 36 /** Did the recognizer encounter a syntax error? Track how many. */ 37 this.syntaxErrors = 0; 38 39 /** If 0, no backtracking is going on. Safe to exec actions etc... 40 * If >0 then it's the level of backtracking. 41 */ 42 this.backtracking = 0; 43 44 /** An array[size num rules] of Map<Integer,Integer> that tracks 45 * the stop token index for each rule. ruleMemo[ruleIndex] is 46 * the memoization table for ruleIndex. For key ruleStartIndex, you 47 * get back the stop token for associated rule or MEMO_RULE_FAILED. 48 * 49 * This is only used if rule memoization is on (which it is by default). 50 */ 51 this.ruleMemo = null; 52 53 54 // LEXER FIELDS (must be in same state object to avoid casting 55 // constantly in generated code and Lexer object) :( 56 57 58 /** The goal of all lexer rules/methods is to create a token object. 59 * This is an instance variable as multiple rules may collaborate to 60 * create a single token. nextToken will return this object after 61 * matching lexer rule(s). If you subclass to allow multiple token 62 * emissions, then set this to the last token to be matched or 63 * something nonnull so that the auto token emit mechanism will not 64 * emit another token. 65 */ 66 this.token = null; 67 68 /** What character index in the stream did the current token start at? 69 * Needed, for example, to get the text for current token. Set at 70 * the start of nextToken. 71 */ 72 this.tokenStartCharIndex = -1; 73 74 /** The line on which the first character of the token resides */ 75 // this.tokenStartLine; 76 77 /** The character position of first character within the line */ 78 // this.tokenStartCharPositionInLine; 79 80 /** The channel number for the current token */ 81 // this.channel; 82 83 /** The token type for the current token */ 84 // this.type; 85 86 /** You can set the text for the current token to override what is in 87 * the input char buffer. Use setText() or can set this instance var. 88 */ 89 this.text = null; 90 }; 91