Package org.antlr.runtime.debug

Class DebugTreeParser

java.lang.Object

org.antlr.runtime.BaseRecognizer

org.antlr.runtime.tree.TreeParser

org.antlr.runtime.debug.DebugTreeParser

public class DebugTreeParser
extends TreeParser

Field Summary

Fields

Modifier and Type	Field	Description
protected DebugEventListener	dbg	Who to notify when events in the parser occur.
boolean	isCyclicDecision	Used to differentiate between fixed lookahead and cyclic DFA decisions while profiling.

Fields inherited from class org.antlr.runtime.tree.TreeParser

DOWN, input, UP

Fields inherited from class org.antlr.runtime.BaseRecognizer

DEFAULT_TOKEN_CHANNEL, HIDDEN, INITIAL_FOLLOW_STACK_SIZE, MEMO_RULE_FAILED, MEMO_RULE_UNKNOWN, NEXT_TOKEN_RULE_NAME, state

Constructor Summary

Constructors

Constructor	Description
DebugTreeParser(TreeNodeStream input, DebugEventListener dbg)
DebugTreeParser(TreeNodeStream input, DebugEventListener dbg, RecognizerSharedState state)	Create a normal parser except wrap the token stream in a debug proxy that fires consume events.
DebugTreeParser(TreeNodeStream input, RecognizerSharedState state)

Method Summary

Modifier and Type	Method	Description
void	beginBacktrack(int level)
void	beginResync()	A hook to listen in on the token consumption during error recovery.
void	endBacktrack(int level, boolean successful)
void	endResync()
DebugEventListener	getDebugListener()
protected Object	getMissingSymbol(IntStream input, RecognitionException e, int expectedTokenType, BitSet follow)	Conjure up a missing token during error recovery.
void	reportError(IOException e)
void	reportError(RecognitionException e)	Report a recognition problem.
void	setDebugListener(DebugEventListener dbg)	Provide a new debug event listener for this parser.

Methods inherited from class org.antlr.runtime.tree.TreeParser

getAncestor, getCurrentInputSymbol, getErrorHeader, getErrorMessage, getSourceName, getTreeNodeStream, inContext, inContext, matchAny, recoverFromMismatchedToken, reset, setTreeNodeStream, traceIn, traceOut

Methods inherited from class org.antlr.runtime.BaseRecognizer

alreadyParsedRule, combineFollows, computeContextSensitiveRuleFOLLOW, computeErrorRecoverySet, consumeUntil, consumeUntil, displayRecognitionError, emitErrorMessage, failed, getBacktrackingLevel, getGrammarFileName, getNumberOfSyntaxErrors, getRuleInvocationStack, getRuleInvocationStack, getRuleMemoization, getRuleMemoizationCacheSize, getTokenErrorDisplay, getTokenNames, match, memoize, mismatchIsMissingToken, mismatchIsUnwantedToken, pushFollow, recover, recoverFromMismatchedSet, setBacktrackingLevel, toStrings, traceIn, traceOut

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

dbg

protected DebugEventListener dbg

Who to notify when events in the parser occur.

isCyclicDecision

public boolean isCyclicDecision

Used to differentiate between fixed lookahead and cyclic DFA decisions while profiling.

Constructor Detail

DebugTreeParser

public DebugTreeParser(TreeNodeStream input,
                       DebugEventListener dbg,
                       RecognizerSharedState state)

Create a normal parser except wrap the token stream in a debug proxy that fires consume events.

DebugTreeParser

public DebugTreeParser(TreeNodeStream input,
                       RecognizerSharedState state)

DebugTreeParser

public DebugTreeParser(TreeNodeStream input,
                       DebugEventListener dbg)

Method Detail

setDebugListener

public void setDebugListener(DebugEventListener dbg)

Provide a new debug event listener for this parser. Notify the input stream too that it should send events to this listener.

getDebugListener

public DebugEventListener getDebugListener()

reportError

public void reportError(IOException e)

reportError

public void reportError(RecognitionException e)

Description copied from class: BaseRecognizer

Report a recognition problem. This method sets errorRecovery to indicate the parser is recovering not parsing. Once in recovery mode, no errors are generated. To get out of recovery mode, the parser must successfully match a token (after a resync). So it will go: 1. error occurs 2. enter recovery mode, report error 3. consume until token found in resynch set 4. try to resume parsing 5. next match() will reset errorRecovery mode If you override, make sure to update syntaxErrors if you care about that.

Overrides:

reportError in class BaseRecognizer

getMissingSymbol

protected Object getMissingSymbol(IntStream input,
                                  RecognitionException e,
                                  int expectedTokenType,
                                  BitSet follow)

Description copied from class: BaseRecognizer

Conjure up a missing token during error recovery. The recognizer attempts to recover from single missing symbols. But, actions might refer to that missing symbol. For example, x=ID {f($x);}. The action clearly assumes that there has been an identifier matched previously and that $x points at that token. If that token is missing, but the next token in the stream is what we want we assume that this token is missing and we keep going. Because we have to return some token to replace the missing token, we have to conjure one up. This method gives the user control over the tokens returned for missing tokens. Mostly, you will want to create something special for identifier tokens. For literals such as '{' and ',', the default action in the parser or tree parser works. It simply creates a CommonToken of the appropriate type. The text will be the token. If you change what tokens must be created by the lexer, override this method to create the appropriate tokens.

Overrides:

getMissingSymbol in class TreeParser

beginResync

public void beginResync()

Description copied from class: BaseRecognizer

A hook to listen in on the token consumption during error recovery. The DebugParser subclasses this to fire events to the listenter.

Overrides:

beginResync in class BaseRecognizer

endResync

public void endResync()

Overrides:

endResync in class BaseRecognizer

beginBacktrack

public void beginBacktrack(int level)

endBacktrack

public void endBacktrack(int level,
                         boolean successful)