2 * Defines the basic structure to support recognizing by either a lexer,
3 * parser, or tree parser.
4 * \addtogroup ANTLR3_BASE_RECOGNIZER
7 #ifndef _ANTLR3_BASERECOGNIZER_H
8 #define _ANTLR3_BASERECOGNIZER_H
10 // [The "BSD licence"]
11 // Copyright (c) 2005-2009 Jim Idle, Temporal Wave LLC
12 // http://www.temporal-wave.com
13 // http://www.linkedin.com/in/jimidle
15 // All rights reserved.
17 // Redistribution and use in source and binary forms, with or without
18 // modification, are permitted provided that the following conditions
20 // 1. Redistributions of source code must retain the above copyright
21 // notice, this list of conditions and the following disclaimer.
22 // 2. Redistributions in binary form must reproduce the above copyright
23 // notice, this list of conditions and the following disclaimer in the
24 // documentation and/or other materials provided with the distribution.
25 // 3. The name of the author may not be used to endorse or promote products
26 // derived from this software without specific prior written permission.
28 // THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
29 // IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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39 #include <antlr3defs.h>
40 #include <antlr3exception.h>
41 #include <antlr3input.h>
42 #include <antlr3tokenstream.h>
43 #include <antlr3commontoken.h>
44 #include <antlr3commontreenodestream.h>
45 #include <antlr3debugeventlistener.h>
46 #include <antlr3recognizersharedstate.h>
48 /** Type indicator for a lexer recognizer
50 #define ANTLR3_TYPE_LEXER 0x0001
52 /** Type indicator for a parser recognizer
54 #define ANTLR3_TYPE_PARSER 0x0002
56 /** Type indicator for a tree parser recognizer
58 #define ANTLR3_TYPE_TREE_PARSER 0x0004
64 /** \brief Base tracking context structure for all types of
67 typedef struct ANTLR3_BASE_RECOGNIZER_struct
69 /// Whatever super structure is providing this interface needs a pointer to itself
70 /// so that this can be passed back to it whenever the api functions
71 /// are called back from here.
75 /// Indicates the type of recognizer that we are an instance of.
76 /// The programmer may set this to anything of course, but the default
77 /// implementations of the interface only really understand the built in
78 /// types, so new error handlers etc would probably be required to as well.
82 /// - #ANTLR3_TYPE_LEXER
83 /// - #ANTLR3_TYPE_PARSER
84 /// - #ANTLR3_TYPE_TREE_PARSER
88 /// A pointer to the shared recognizer state, such that multiple
89 /// recognizers can use the same inputs streams and so on (in
90 /// the case of grammar inheritance for instance.
92 pANTLR3_RECOGNIZER_SHARED_STATE state
;
94 /// If set to something other than NULL, then this structure is
95 /// points to an instance of the debugger interface. In general, the
96 /// debugger is only referenced internally in recovery/error operations
97 /// so that it does not cause overhead by having to check this pointer
98 /// in every function/method
100 pANTLR3_DEBUG_EVENT_LISTENER debugger
;
103 /// Pointer to a function that matches the current input symbol
104 /// against the supplied type. the function causes an error if a
105 /// match is not found and the default implementation will also
106 /// attempt to perform one token insertion or deletion if that is
107 /// possible with the input stream. You can override the default
108 /// implementation by installing a pointer to your own function
109 /// in this interface after the recognizer has initialized. This can
110 /// perform different recovery options or not recover at all and so on.
111 /// To ignore recovery altogether, see the comments in the default
112 /// implementation of this function in antlr3baserecognizer.c
114 /// Note that errors are signalled by setting the error flag below
115 /// and creating a new exception structure and installing it in the
116 /// exception pointer below (you can chain these if you like and handle them
117 /// in some customized way).
119 void * (*match
) (struct ANTLR3_BASE_RECOGNIZER_struct
* recognizer
,
120 ANTLR3_UINT32 ttype
, pANTLR3_BITSET_LIST follow
);
122 /// Pointer to a function that matches the next token/char in the input stream
123 /// regardless of what it actually is.
125 void (*matchAny
) (struct ANTLR3_BASE_RECOGNIZER_struct
* recognizer
);
127 /// Pointer to a function that decides if the token ahead of the current one is the
128 /// one we were loking for, in which case the curernt one is very likely extraneous
129 /// and can be reported that way.
132 (*mismatchIsUnwantedToken
) (struct ANTLR3_BASE_RECOGNIZER_struct
* recognizer
, pANTLR3_INT_STREAM input
, ANTLR3_UINT32 ttype
);
134 /// Pointer to a function that decides if the current token is one that can logically
135 /// follow the one we were looking for, in which case the one we were looking for is
136 /// probably missing from the input.
139 (*mismatchIsMissingToken
) (struct ANTLR3_BASE_RECOGNIZER_struct
* recognizer
, pANTLR3_INT_STREAM input
, pANTLR3_BITSET_LIST follow
);
141 /** Pointer to a function that works out what to do when a token mismatch
142 * occurs, so that Tree parsers can behave differently to other recognizers.
144 void (*mismatch
) (struct ANTLR3_BASE_RECOGNIZER_struct
* recognizer
,
145 ANTLR3_UINT32 ttype
, pANTLR3_BITSET_LIST follow
);
147 /** Pointer to a function to call to report a recognition problem. You may override
148 * this function with your own function, but refer to the standard implementation
149 * in antlr3baserecognizer.c for guidance. The function should recognize whether
150 * error recovery is in force, so that it does not print out more than one error messages
151 * for the same error. From the java comments in BaseRecognizer.java:
153 * This method sets errorRecovery to indicate the parser is recovering
154 * not parsing. Once in recovery mode, no errors are generated.
155 * To get out of recovery mode, the parser must successfully match
156 * a token (after a resync). So it will go:
159 * 2. enter recovery mode, report error
160 * 3. consume until token found in resynch set
161 * 4. try to resume parsing
162 * 5. next match() will reset errorRecovery mode
164 void (*reportError
) (struct ANTLR3_BASE_RECOGNIZER_struct
* recognizer
);
166 /** Pointer to a function that is called to display a recognition error message. You may
167 * override this function independently of (*reportError)() above as that function calls
168 * this one to do the actual exception printing.
170 void (*displayRecognitionError
) (struct ANTLR3_BASE_RECOGNIZER_struct
* recognizer
, pANTLR3_UINT8
* tokenNames
);
172 /// Get number of recognition errors (lexer, parser, tree parser). Each
173 /// recognizer tracks its own number. So parser and lexer each have
174 /// separate count. Does not count the spurious errors found between
175 /// an error and next valid token match
177 /// \see reportError()
180 (*getNumberOfSyntaxErrors
) (struct ANTLR3_BASE_RECOGNIZER_struct
* recognizer
);
182 /** Pointer to a function that recovers from an error found in the input stream.
183 * Generally, this will be a #ANTLR3_EXCEPTION_NOVIABLE_ALT but it could also
184 * be from a mismatched token that the (*match)() could not recover from.
186 void (*recover
) (struct ANTLR3_BASE_RECOGNIZER_struct
* recognizer
);
188 /** Pointer to a function that is a hook to listen to token consumption during error recovery.
189 * This is mainly used by the debug parser to send events to the listener.
191 void (*beginResync
) (struct ANTLR3_BASE_RECOGNIZER_struct
* recognizer
);
193 /** Pointer to a function that is a hook to listen to token consumption during error recovery.
194 * This is mainly used by the debug parser to send events to the listener.
196 void (*endResync
) (struct ANTLR3_BASE_RECOGNIZER_struct
* recognizer
);
198 /** Pointer to a function that is a hook to listen to token consumption during error recovery.
199 * This is mainly used by the debug parser to send events to the listener.
201 void (*beginBacktrack
) (struct ANTLR3_BASE_RECOGNIZER_struct
* recognizer
, ANTLR3_UINT32 level
);
203 /** Pointer to a function that is a hook to listen to token consumption during error recovery.
204 * This is mainly used by the debug parser to send events to the listener.
206 void (*endBacktrack
) (struct ANTLR3_BASE_RECOGNIZER_struct
* recognizer
, ANTLR3_UINT32 level
, ANTLR3_BOOLEAN successful
);
208 /** Pointer to a function to computer the error recovery set for the current rule.
209 * \see antlr3ComputeErrorRecoverySet() for details.
211 pANTLR3_BITSET (*computeErrorRecoverySet
) (struct ANTLR3_BASE_RECOGNIZER_struct
* recognizer
);
213 /** Pointer to a function that computes the context-sensitive FOLLOW set for the
215 * \see antlr3ComputeCSRuleFollow() for details.
217 pANTLR3_BITSET (*computeCSRuleFollow
) (struct ANTLR3_BASE_RECOGNIZER_struct
* recognizer
);
219 /** Pointer to a function to combine follow bitsets.
220 * \see antlr3CombineFollows() for details.
222 pANTLR3_BITSET (*combineFollows
) (struct ANTLR3_BASE_RECOGNIZER_struct
* recognizer
,
223 ANTLR3_BOOLEAN exact
);
225 /** Pointer to a function that recovers from a mismatched token in the input stream.
226 * \see antlr3RecoverMismatch() for details.
228 void * (*recoverFromMismatchedToken
)
229 (struct ANTLR3_BASE_RECOGNIZER_struct
* recognizer
,
231 pANTLR3_BITSET_LIST follow
);
233 /** Pointer to a function that recovers from a mismatched set in the token stream, in a similar manner
234 * to (*recoverFromMismatchedToken)
236 void * (*recoverFromMismatchedSet
) (struct ANTLR3_BASE_RECOGNIZER_struct
* recognizer
,
237 pANTLR3_BITSET_LIST follow
);
239 /** Pointer to common routine to handle single token insertion for recovery functions.
241 ANTLR3_BOOLEAN (*recoverFromMismatchedElement
)
242 (struct ANTLR3_BASE_RECOGNIZER_struct
* recognizer
,
243 pANTLR3_BITSET_LIST follow
);
245 /** Pointer to function that consumes input until the next token matches
248 void (*consumeUntil
) (struct ANTLR3_BASE_RECOGNIZER_struct
* recognizer
,
249 ANTLR3_UINT32 tokenType
);
251 /** Pointer to function that consumes input until the next token matches
252 * one in the given set.
254 void (*consumeUntilSet
) (struct ANTLR3_BASE_RECOGNIZER_struct
* recognizer
,
257 /** Pointer to function that returns an ANTLR3_LIST of the strings that identify
258 * the rules in the parser that got you to this point. Can be overridden by installing your
261 * \todo Document how to override invocation stack functions.
263 pANTLR3_STACK (*getRuleInvocationStack
) (struct ANTLR3_BASE_RECOGNIZER_struct
* recognizer
);
264 pANTLR3_STACK (*getRuleInvocationStackNamed
) (struct ANTLR3_BASE_RECOGNIZER_struct
* recognizer
,
267 /** Pointer to a function that converts an ANLR3_LIST of tokens to an ANTLR3_LIST of
268 * string token names. As this is mostly used in string template processing it may not be useful
271 pANTLR3_HASH_TABLE (*toStrings
) (struct ANTLR3_BASE_RECOGNIZER_struct
* recognizer
,
274 /** Pointer to a function to return whether the rule has parsed input starting at the supplied
275 * start index before. If the rule has not parsed input starting from the supplied start index,
276 * then it will return ANTLR3_MEMO_RULE_UNKNOWN. If it has parsed from the suppled start point
277 * then it will return the point where it last stopped parsing after that start point.
279 ANTLR3_MARKER (*getRuleMemoization
) (struct ANTLR3_BASE_RECOGNIZER_struct
* recognizer
,
280 ANTLR3_INTKEY ruleIndex
,
281 ANTLR3_MARKER ruleParseStart
);
283 /** Pointer to function that determines whether the rule has parsed input at the current index
284 * in the input stream
286 ANTLR3_BOOLEAN (*alreadyParsedRule
) (struct ANTLR3_BASE_RECOGNIZER_struct
* recognizer
,
287 ANTLR3_MARKER ruleIndex
);
289 /** Pointer to function that records whether the rule has parsed the input at a
290 * current position successfully or not.
292 void (*memoize
) (struct ANTLR3_BASE_RECOGNIZER_struct
* recognizer
,
293 ANTLR3_MARKER ruleIndex
,
294 ANTLR3_MARKER ruleParseStart
);
296 /// Pointer to a function that returns the current input symbol.
297 /// The is placed into any label for the associated token ref; e.g., x=ID. Token
298 /// and tree parsers need to return different objects. Rather than test
299 /// for input stream type or change the IntStream interface, I use
300 /// a simple method to ask the recognizer to tell me what the current
303 /// This is ignored for lexers and the lexer implementation of this
304 /// function should return NULL.
306 void * (*getCurrentInputSymbol
) ( struct ANTLR3_BASE_RECOGNIZER_struct
* recognizer
,
307 pANTLR3_INT_STREAM istream
);
309 /// Conjure up a missing token during error recovery.
311 /// The recognizer attempts to recover from single missing
312 /// symbols. But, actions might refer to that missing symbol.
313 /// For example, x=ID {f($x);}. The action clearly assumes
314 /// that there has been an identifier matched previously and that
315 /// $x points at that token. If that token is missing, but
316 /// the next token in the stream is what we want we assume that
317 /// this token is missing and we keep going. Because we
318 /// have to return some token to replace the missing token,
319 /// we have to conjure one up. This method gives the user control
320 /// over the tokens returned for missing tokens. Mostly,
321 /// you will want to create something special for identifier
322 /// tokens. For literals such as '{' and ',', the default
323 /// action in the parser or tree parser works. It simply creates
324 /// a CommonToken of the appropriate type. The text will be the token.
325 /// If you change what tokens must be created by the lexer,
326 /// override this method to create the appropriate tokens.
328 void * (*getMissingSymbol
) ( struct ANTLR3_BASE_RECOGNIZER_struct
* recognizer
,
329 pANTLR3_INT_STREAM istream
,
331 ANTLR3_UINT32 expectedTokenType
,
332 pANTLR3_BITSET_LIST follow
);
334 /** Pointer to a function that returns whether the supplied grammar function
335 * will parse the current input stream or not. This is the way that syntactic
336 * predicates are evaluated. Unlike java, C is perfectly happy to invoke code
337 * via a pointer to a function (hence that's what all the ANTLR3 C interfaces
340 ANTLR3_BOOLEAN (*synpred
) ( struct ANTLR3_BASE_RECOGNIZER_struct
* recognizer
, void * ctx
,
341 void (*predicate
)(void * ctx
));
343 /** Pointer to a function that can construct a generic exception structure
344 * with such information as the input stream can provide.
346 void (*exConstruct
) (struct ANTLR3_BASE_RECOGNIZER_struct
* recognizer
);
348 /** Reset the recognizer
350 void (*reset
) (struct ANTLR3_BASE_RECOGNIZER_struct
* recognizer
);
352 /** Pointer to a function that knows how to free the resources of a base recognizer.
354 void (*free
) (struct ANTLR3_BASE_RECOGNIZER_struct
* recognizer
);
356 /* Added to support custom error handling */
360 ANTLR3_BASE_RECOGNIZER
;
366 #include <antlr3lexer.h>
367 #include <antlr3parser.h>
368 #include <antlr3treeparser.h>
373 #endif /* _ANTLR3_BASERECOGNIZER_H */